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2016 Volume 34 Issue 1
2016, 34(1): 1-1
doi: 10.3724/SP.J.1123.2015.10019
Abstract:
2016, 34(1): 2-3
doi: 10.3724/SP.J.1123.2015.06043
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2016, 34(1): 4-9
doi: 10.3724/SP.J.1123.2015.10037
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Two novel polymers containing glucose units as the main-chain that only differ in terms of their regioregularity were synthesized to evaluate their chiral recognition abilities as chiral stationary phases (CSPs) for high performance liquid chromatography (HPLC). The regioregular polymer (poly-5) shows clear resolution ability for the racemate of cobalt (Ⅲ) acetylacetonate (Co(acac)3), whereas the corresponding regioirregular polymer (poly-3) does not show any chiral recognition for Co(acac)3. The regioregular polymer main-chain seems to play an important role not only in providing an efficient interaction with the racemate but also in expressing the chiral recognition ability as a CSP for HPLC.
Two novel polymers containing glucose units as the main-chain that only differ in terms of their regioregularity were synthesized to evaluate their chiral recognition abilities as chiral stationary phases (CSPs) for high performance liquid chromatography (HPLC). The regioregular polymer (poly-5) shows clear resolution ability for the racemate of cobalt (Ⅲ) acetylacetonate (Co(acac)3), whereas the corresponding regioirregular polymer (poly-3) does not show any chiral recognition for Co(acac)3. The regioregular polymer main-chain seems to play an important role not only in providing an efficient interaction with the racemate but also in expressing the chiral recognition ability as a CSP for HPLC.
2016, 34(1): 10-15
doi: 10.3724/SP.J.1123.2015.10005
Abstract:
Chirality is a universal phenomenon in nature. Chiral separation is vitally important in drug development, agricultural chemistry, pharmacology, environmental science, biology and many other fields. Chiral metal-organic frameworks (MOFs) are a new group of porous materials with special topology and designable pore structures, as well as their high specific surface area, porosity, excellent thermal stability, solvent resistance, etc. Thus, chiral MOFs are promising with various applications in the field of analytical chemistry. This review summarizes the synthesis strategies of chiral MOFs and their applications in the selective separation of enantiomers, as well as related mechanism.
Chirality is a universal phenomenon in nature. Chiral separation is vitally important in drug development, agricultural chemistry, pharmacology, environmental science, biology and many other fields. Chiral metal-organic frameworks (MOFs) are a new group of porous materials with special topology and designable pore structures, as well as their high specific surface area, porosity, excellent thermal stability, solvent resistance, etc. Thus, chiral MOFs are promising with various applications in the field of analytical chemistry. This review summarizes the synthesis strategies of chiral MOFs and their applications in the selective separation of enantiomers, as well as related mechanism.
2016, 34(1): 16-20
doi: 10.3724/SP.J.1123.2015.09002
Abstract:
As the two enantiomers of chiral compounds have different chemical and physiologic properties, the enantioseparation of chiral compounds is of great significance in the fields such as medicine, biology, food and environment. Hence, the enantioseparation of different types of chiral compounds has become one of the hottest research topics in recent years. Capillary electrophoresis, owing to its unique advantages, has a wide application in the enantioseparation field recently. In this review, the latest research progresses in capillary electrophoresis enantioseparation are summarized from 2013 to 2015, and the future developments in this field is also prospected.
As the two enantiomers of chiral compounds have different chemical and physiologic properties, the enantioseparation of chiral compounds is of great significance in the fields such as medicine, biology, food and environment. Hence, the enantioseparation of different types of chiral compounds has become one of the hottest research topics in recent years. Capillary electrophoresis, owing to its unique advantages, has a wide application in the enantioseparation field recently. In this review, the latest research progresses in capillary electrophoresis enantioseparation are summarized from 2013 to 2015, and the future developments in this field is also prospected.
2016, 34(1): 21-27
doi: 10.3724/SP.J.1123.2015.05038
Abstract:
Enantioseparation of D,L-amino acids is of great significance in life science. As one of the most useful methods, chiral ligand exchange capillary electrophoresis possesses many advantages, including high efficiency, fast speed and tunable migration order, and it has attracted great research interest. This review summarizes the development of chiral ligand exchange capillary electrophoresis for enantioseparation of D,L-amino acids in recent years.
Enantioseparation of D,L-amino acids is of great significance in life science. As one of the most useful methods, chiral ligand exchange capillary electrophoresis possesses many advantages, including high efficiency, fast speed and tunable migration order, and it has attracted great research interest. This review summarizes the development of chiral ligand exchange capillary electrophoresis for enantioseparation of D,L-amino acids in recent years.
2016, 34(1): 28-33
doi: 10.3724/SP.J.1123.2015.08014
Abstract:
In recent eight years, authors' group has repeated a lot of experiments of chiral thin layer chromatography coming from literature. From the practical opinion, we summarized that there are nine characteristics for chiral thin layer chromatography. Some progresses of chiral thin layer chromatography are reviewed, and the enantioselectivity of a commercial chiral thin layer plate is introduced. The study of vancomycin as the chiral selector in thin layer chromatography is also reported.
In recent eight years, authors' group has repeated a lot of experiments of chiral thin layer chromatography coming from literature. From the practical opinion, we summarized that there are nine characteristics for chiral thin layer chromatography. Some progresses of chiral thin layer chromatography are reviewed, and the enantioselectivity of a commercial chiral thin layer plate is introduced. The study of vancomycin as the chiral selector in thin layer chromatography is also reported.
2016, 34(1): 34-43
doi: 10.3724/SP.J.1123.2015.10023
Abstract:
The applications of chiral drugs had a profound impact on human health. With the development of disciplines of chemistry, materials and life science, the research on the separation and analysis of chiral drugs became intensified. Chromatography and the selection of chiral stationary phase played important roles in resolving chiral drugs. The optimization of polymer materials and their derivatives as chiral stationary phase become the main issue in recent years. Recent studies as well as prospects in polymer materials used as chiral stationary phase are presented in this paper.
The applications of chiral drugs had a profound impact on human health. With the development of disciplines of chemistry, materials and life science, the research on the separation and analysis of chiral drugs became intensified. Chromatography and the selection of chiral stationary phase played important roles in resolving chiral drugs. The optimization of polymer materials and their derivatives as chiral stationary phase become the main issue in recent years. Recent studies as well as prospects in polymer materials used as chiral stationary phase are presented in this paper.
2016, 34(1): 44-49
doi: 10.3724/SP.J.1123.2015.09013
Abstract:
This article summarizes five characteristics of chiral countercurrent chromatography (CCC). The progress of chiral countercurrent chromatography is introduced. In the high speed countercurrent chromatography, the chiral selectors such as amino acid derivatives, cyclodextrin derivatives, chiral organic acid, polysaccharide and bovine serum albumin (BSA) are reviewed.
This article summarizes five characteristics of chiral countercurrent chromatography (CCC). The progress of chiral countercurrent chromatography is introduced. In the high speed countercurrent chromatography, the chiral selectors such as amino acid derivatives, cyclodextrin derivatives, chiral organic acid, polysaccharide and bovine serum albumin (BSA) are reviewed.
2016, 34(2): 130-139
doi: 10.3724/SP.J.1123.2015.11005
Abstract:
The optical absorption detector is one of the most commonly used detectors for high performance liquid chromatography (HPLC). As a core part of this kind of detector, the designs of flow cells, where light passes through samples for acquiring samples information, will affect the performance of a detector. In order to enhance the signal to noise ratio of detectors and reduce the bands broadening that come from flow cells, it is necessary to design a flow cell with a longer optical path length and a less cell volume while maintaining the luminous flux. However the limitations of the machining capacity make it difficult to increase the optical path length, reduce the cell volume and keep or increase the luminous flux simultaneously. It is a challenge to optimize the designing and machining of flow cells so as to improve the performance of detectors. This review discusses the development of designing flow cells based on the detection principle in some aspects of increasing the optical path length, reducing the cell volume, taking the advantages of total reflection and so on. At the same time, some of the designs are illustrated in detail. These various ideas and structures are significant references for designing flow cells and developing optical absorption detectors.
The optical absorption detector is one of the most commonly used detectors for high performance liquid chromatography (HPLC). As a core part of this kind of detector, the designs of flow cells, where light passes through samples for acquiring samples information, will affect the performance of a detector. In order to enhance the signal to noise ratio of detectors and reduce the bands broadening that come from flow cells, it is necessary to design a flow cell with a longer optical path length and a less cell volume while maintaining the luminous flux. However the limitations of the machining capacity make it difficult to increase the optical path length, reduce the cell volume and keep or increase the luminous flux simultaneously. It is a challenge to optimize the designing and machining of flow cells so as to improve the performance of detectors. This review discusses the development of designing flow cells based on the detection principle in some aspects of increasing the optical path length, reducing the cell volume, taking the advantages of total reflection and so on. At the same time, some of the designs are illustrated in detail. These various ideas and structures are significant references for designing flow cells and developing optical absorption detectors.
2016, 34(1): 50-56
doi: 10.3724/SP.J.1123.2015.10015
Abstract:
Five new amylose derivatives, namely amylose 2-benzoate-3-(4-chlorophenylcarbamate)-6-(3,5-dimethylphenylcarbamate), amylose 2-benzoate-3-(4-chlorophenylcarbamate)-6-(3,5-dichlorophenylcarbamate), amylose 2-benzoate-3,6-bis(4-chlorophenylcarbamate), amylose 2-(4-chlorobenzoate)-3,6-bis(4-chlorophenylcarbamate) and amylose 2-(4-chlorobenzoate)-3,6-biscyclohexylcarbamate, were synthesized by a series of regioselective process. These derivatives were then coated on the surface of aminopropyl silica gels, and used as chiral stationary phases (CSPs) for high performance liquid chromatography (HPLC). These derivatives were characterized by 1H-nuclear magnetic resonance (1H-NMR) and Fourier transform infrared (FT-IR) spectroscopies, and their chiral recognition abilities were evaluated using nine racemates by HPLC. Compared with other amylose derivatives, some racemates were better resolved on the new CSPs. The obtained results indicate that the property and position of substituents at 2-, 3- and 6-positions of glucose unit have great influence on the chiral recognition abilities of the amylose derivatives.
Five new amylose derivatives, namely amylose 2-benzoate-3-(4-chlorophenylcarbamate)-6-(3,5-dimethylphenylcarbamate), amylose 2-benzoate-3-(4-chlorophenylcarbamate)-6-(3,5-dichlorophenylcarbamate), amylose 2-benzoate-3,6-bis(4-chlorophenylcarbamate), amylose 2-(4-chlorobenzoate)-3,6-bis(4-chlorophenylcarbamate) and amylose 2-(4-chlorobenzoate)-3,6-biscyclohexylcarbamate, were synthesized by a series of regioselective process. These derivatives were then coated on the surface of aminopropyl silica gels, and used as chiral stationary phases (CSPs) for high performance liquid chromatography (HPLC). These derivatives were characterized by 1H-nuclear magnetic resonance (1H-NMR) and Fourier transform infrared (FT-IR) spectroscopies, and their chiral recognition abilities were evaluated using nine racemates by HPLC. Compared with other amylose derivatives, some racemates were better resolved on the new CSPs. The obtained results indicate that the property and position of substituents at 2-, 3- and 6-positions of glucose unit have great influence on the chiral recognition abilities of the amylose derivatives.
2016, 34(1): 57-61
doi: 10.3724/SP.J.1123.2015.10002
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The method for the enantioseparation of ferroence derivatives, four derivatives with single chirality and three derivatives with double chiralities containing centre and face chirality, on chiral stationary phases, namely Chiralpak IC (cellulose-tris(3,5-dichlorobenzene carbamate)) and Chiralpak IE3 (amylose-tris(3,5-dichlorobenzene carbamate)), was investigated. We found that the three derivatives of the four chiral ferroence derivatives with single chirality can be baseline separated on Chiralpak IE3; another one can be baseline separated on Chiralpak IC. Meanwhile, the three chiral ferroence derivatives with double chiralities can be baseline separated on Chiralpak IC. The research shows that the both kinds of chiral stationary phases exhibited high enantiomeric recognition capability to the enantiomers of the chiral ferroence derivatives. This two chiral stationary phases exhibited complementary selectivities in the enantioseparation of chiral ferroence derivatives. This study provides a reference method for the enantioseparation of chiral ferroence derivatives.
The method for the enantioseparation of ferroence derivatives, four derivatives with single chirality and three derivatives with double chiralities containing centre and face chirality, on chiral stationary phases, namely Chiralpak IC (cellulose-tris(3,5-dichlorobenzene carbamate)) and Chiralpak IE3 (amylose-tris(3,5-dichlorobenzene carbamate)), was investigated. We found that the three derivatives of the four chiral ferroence derivatives with single chirality can be baseline separated on Chiralpak IE3; another one can be baseline separated on Chiralpak IC. Meanwhile, the three chiral ferroence derivatives with double chiralities can be baseline separated on Chiralpak IC. The research shows that the both kinds of chiral stationary phases exhibited high enantiomeric recognition capability to the enantiomers of the chiral ferroence derivatives. This two chiral stationary phases exhibited complementary selectivities in the enantioseparation of chiral ferroence derivatives. This study provides a reference method for the enantioseparation of chiral ferroence derivatives.
2016, 34(1): 62-67
doi: 10.3724/SP.J.1123.2015.07015
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A novel chiral stationary phase combining quinine and crown ether (QN-CR CSP) was developed to separate amino acid enantiomers. This CSP showed good enantioselectivity for some amino acids. Since the synergistic effect of ion exchange and complexation in chiral recognition of amino acids, a new adsorption isotherm was built. Using the method of frontal analysis by characteristic point (FACP), the adsorption isotherms of tryptophan (Trp) under different mobile phase conditions were determined and fitted the proposed adsorption isotherm model well. With the increase of the competition between metal cationic and amino to crown ether, the equilibrium constant of complexing adsorption was found increased. The chiral separation ability was decreased. The adsorption isotherm improved the understanding of the retention behavior of amino acids on QN-CR CSP, which was also benefit to optimize the structure of the stationary phase.
A novel chiral stationary phase combining quinine and crown ether (QN-CR CSP) was developed to separate amino acid enantiomers. This CSP showed good enantioselectivity for some amino acids. Since the synergistic effect of ion exchange and complexation in chiral recognition of amino acids, a new adsorption isotherm was built. Using the method of frontal analysis by characteristic point (FACP), the adsorption isotherms of tryptophan (Trp) under different mobile phase conditions were determined and fitted the proposed adsorption isotherm model well. With the increase of the competition between metal cationic and amino to crown ether, the equilibrium constant of complexing adsorption was found increased. The chiral separation ability was decreased. The adsorption isotherm improved the understanding of the retention behavior of amino acids on QN-CR CSP, which was also benefit to optimize the structure of the stationary phase.
2016, 34(1): 68-73
doi: 10.3724/SP.J.1123.2015.10024
Abstract:
Due to some advantages such as high precision, high efficiency and low consumption of organic solvents, chromatographic separation technique by simulated moving bed (SMB) has attracted considerable attention in the past decades. Herein, the enantioseparation of metalaxyl racemate on EnantioPak OD columns has been carried out by SMB chromatography with the mixture of hexane-ethanol (70 : 30, v/v). The elution order of two metalaxyl enantiomers under current chromatographic conditions was determined by HPLC with the optical rotation detector. Then, the influence of running parameters, such as the concentration, flow rate and switch time on the resolution of metalaxyl racemate has been studied in detail. In addition, the separation results from SMB and the preparative chromatography have been compared under the same concentrations. The results showed that the retention of S-(+)-metalaxyl was weaker than R-(-)-metalaxyl and S-(+)-metalaxyl was eluted first. Most importantly, metalaxyl racemate was well separated by SMB chromatography under linear or non-linear conditions, and the purity of each enantiomer product was over 99%. Furthermore, the amount separated by SMB was much more than by the preparative chromatography with racemate concentration of 15 mg/mL, and the mobile phase consumption was one-ninth of the latter. In brief, these results provide us important information for the future development of large-scale chromatographic separation of metalaxyl enantiomers.
Due to some advantages such as high precision, high efficiency and low consumption of organic solvents, chromatographic separation technique by simulated moving bed (SMB) has attracted considerable attention in the past decades. Herein, the enantioseparation of metalaxyl racemate on EnantioPak OD columns has been carried out by SMB chromatography with the mixture of hexane-ethanol (70 : 30, v/v). The elution order of two metalaxyl enantiomers under current chromatographic conditions was determined by HPLC with the optical rotation detector. Then, the influence of running parameters, such as the concentration, flow rate and switch time on the resolution of metalaxyl racemate has been studied in detail. In addition, the separation results from SMB and the preparative chromatography have been compared under the same concentrations. The results showed that the retention of S-(+)-metalaxyl was weaker than R-(-)-metalaxyl and S-(+)-metalaxyl was eluted first. Most importantly, metalaxyl racemate was well separated by SMB chromatography under linear or non-linear conditions, and the purity of each enantiomer product was over 99%. Furthermore, the amount separated by SMB was much more than by the preparative chromatography with racemate concentration of 15 mg/mL, and the mobile phase consumption was one-ninth of the latter. In brief, these results provide us important information for the future development of large-scale chromatographic separation of metalaxyl enantiomers.
2016, 34(1): 74-79
doi: 10.3724/SP.J.1123.2015.10036
Abstract:
High performance liquid chromatography (HPLC) has been widely considered as the most effective way for the separation and preparation of optically pure enantiomers. In the resolution by HPLC, the separation ability of a column strongly depends on the properties of a chiral stationary phase (CSP). Among many CSPs, the immobilized CSPs, which are becoming one of the most important kinds of CSPs, have the advantages of good solvent durability and enormous method flexibility. In this work, a novel optically active acrylamide derivative (S)-APACP was synthesized by two-step reactions, and its chemical structure was characterized by 1H NMR. The polyacrylamide derivatives were immobilized on silica gel by three-step reactions to prepare immobilized CSPs, and the immobilization amount of the polymers was tested by thermogravimetric analysis. The chiral recognition ability of the immobilized CSPs was evaluated by HPLC, and the effects of Lewis acid and mobile phase on the chiral recognition ability were investigated. The results showed that APACP polymer was successfully immobilized on silica gel to prepare immobilized-type CSP with better solvent durability, and the amount of immobilized polymer was 10.2% to 11.8%. The immobilized-type CSP showed good chiral recognition ability for several enantiomers.
High performance liquid chromatography (HPLC) has been widely considered as the most effective way for the separation and preparation of optically pure enantiomers. In the resolution by HPLC, the separation ability of a column strongly depends on the properties of a chiral stationary phase (CSP). Among many CSPs, the immobilized CSPs, which are becoming one of the most important kinds of CSPs, have the advantages of good solvent durability and enormous method flexibility. In this work, a novel optically active acrylamide derivative (S)-APACP was synthesized by two-step reactions, and its chemical structure was characterized by 1H NMR. The polyacrylamide derivatives were immobilized on silica gel by three-step reactions to prepare immobilized CSPs, and the immobilization amount of the polymers was tested by thermogravimetric analysis. The chiral recognition ability of the immobilized CSPs was evaluated by HPLC, and the effects of Lewis acid and mobile phase on the chiral recognition ability were investigated. The results showed that APACP polymer was successfully immobilized on silica gel to prepare immobilized-type CSP with better solvent durability, and the amount of immobilized polymer was 10.2% to 11.8%. The immobilized-type CSP showed good chiral recognition ability for several enantiomers.
2016, 34(1): 80-84
doi: 10.3724/SP.J.1123.2015.10039
Abstract:
Eleven kinds of chiral compounds have been well separated within 10 min on polysaccharide derivative-based chiral stationary phases named Chiralpak IA, IB, IC, ID, IE and IF by supercritical fluid chromatography (SFC). The chiral recognition of these chiral compounds has demonstrated good complementary enantioselectivities of the six chiral columns, which were proved to be useful for chiral SFC. Both the elution time and enantioselectivies could be significantly affected by the modifier types and their concentrations, such as methanol, ethanol and isopropanol, which should be optimized during the experiments. In addition, the solvent versatility of the immobilized chiral stationary phase on the optimization of the chiral separation was helpful.
Eleven kinds of chiral compounds have been well separated within 10 min on polysaccharide derivative-based chiral stationary phases named Chiralpak IA, IB, IC, ID, IE and IF by supercritical fluid chromatography (SFC). The chiral recognition of these chiral compounds has demonstrated good complementary enantioselectivities of the six chiral columns, which were proved to be useful for chiral SFC. Both the elution time and enantioselectivies could be significantly affected by the modifier types and their concentrations, such as methanol, ethanol and isopropanol, which should be optimized during the experiments. In addition, the solvent versatility of the immobilized chiral stationary phase on the optimization of the chiral separation was helpful.
2016, 34(1): 85-88
doi: 10.3724/SP.J.1123.2015.06044
Abstract:
Chiral 2-arylcarboxylic acid derivatives are important intermediates for preparing 2-arylcarboxylic acids, which are non-steroidal anti-inflammatory drugs (NSAIDs). In order to separate 2-phenylcarboxylic acid ester enantiomers by capillary gas chromatography (CGC), 2,6-di-O-pentyl-3-O-butyryl- β-cyclodextrin and 2,6-di-O-benzyl-3-O-heptanoyl- β-cyclodextrin were used as CGC chiral stationary phases, separately, and their enantioseparation abilities to enantiomers of methyl 2-phenylbutanoate, ethyl 2-phenylbutanoate, isopropyl 2-phenylbutanoate, methyl 2-phenylpropionate and cyclopentyl 2-phenylpropionate were examined. It was found that methyl 2-phenylbutanoate, methyl 2-phenylpropionate and cyclopentyl 2-phenylpropionate were successfully separated by using 2,6-di-O-pentyl-3-O-butyryl- β-cyclodextrin and 2,6-di-O-benzyl-3-O-heptanoyl- β-cyclodextrin as CGC chiral stationary phases, respectively. The enantiomer separation abilities of 2,6-di-O-pentyl-3-O-butyryl- β-cyclodextrin to the three pairs of 2-phenylcarboxylic acid esters tested are superior to those of 2,6-di-O-benzyl-3-O-heptanoyl- β-cyclodextrin.
Chiral 2-arylcarboxylic acid derivatives are important intermediates for preparing 2-arylcarboxylic acids, which are non-steroidal anti-inflammatory drugs (NSAIDs). In order to separate 2-phenylcarboxylic acid ester enantiomers by capillary gas chromatography (CGC), 2,6-di-O-pentyl-3-O-butyryl- β-cyclodextrin and 2,6-di-O-benzyl-3-O-heptanoyl- β-cyclodextrin were used as CGC chiral stationary phases, separately, and their enantioseparation abilities to enantiomers of methyl 2-phenylbutanoate, ethyl 2-phenylbutanoate, isopropyl 2-phenylbutanoate, methyl 2-phenylpropionate and cyclopentyl 2-phenylpropionate were examined. It was found that methyl 2-phenylbutanoate, methyl 2-phenylpropionate and cyclopentyl 2-phenylpropionate were successfully separated by using 2,6-di-O-pentyl-3-O-butyryl- β-cyclodextrin and 2,6-di-O-benzyl-3-O-heptanoyl- β-cyclodextrin as CGC chiral stationary phases, respectively. The enantiomer separation abilities of 2,6-di-O-pentyl-3-O-butyryl- β-cyclodextrin to the three pairs of 2-phenylcarboxylic acid esters tested are superior to those of 2,6-di-O-benzyl-3-O-heptanoyl- β-cyclodextrin.
2016, 34(1): 89-95
doi: 10.3724/SP.J.1123.2015.06036
Abstract:
A simple preparation method for β-cyclodextrin-silica hybrid chiral stationary phases was developed. Firstly, the β-cyclodextrin-silica derivative was synthesized by the reaction of 3-aminopropyltriethoxysilane and monochlorotriazinyl β-cyclodextrin under weak base condition. Spherical β-cyclodextrin-silica hybrid materials with β-cyclodextrin in the surface of pores by covalent bonding were prepared using 1,2-bis(triethoxysilyl) ethane and the β-cyclodextrin-silica derivative under the alkaline condition by one-step polymerization reaction. The β-Cyclodextrin-silica hybrid chiral stationary phases could be directly used as high performance liquid chromatographic packings after the template removal. The hybrid materials prepared in this paper possessed regular spherical morphology, good monodispersion, high specific surface area, good mechanical property, high chemical stability and simple preparation process. It combined the chiral recognition performance of β-cyclodextrin and the outstanding performance of organic-inorganic hybrid material. The effect of the composition, ratio and pH of mobile phase on chiral separation was investigated, and the best chiral separation conditions had been optimized. The baseline chiral separations for five chiral compounds were obtained under the optimal conditions. The results of enantioseparation showed that the hybrid chiral stationary phases had favorable chiral recognition ability. Compared with the traditional preparation process of chiral stationary phases, a new thought for new type of chiral stationary phase is provided by the present method in this paper.
A simple preparation method for β-cyclodextrin-silica hybrid chiral stationary phases was developed. Firstly, the β-cyclodextrin-silica derivative was synthesized by the reaction of 3-aminopropyltriethoxysilane and monochlorotriazinyl β-cyclodextrin under weak base condition. Spherical β-cyclodextrin-silica hybrid materials with β-cyclodextrin in the surface of pores by covalent bonding were prepared using 1,2-bis(triethoxysilyl) ethane and the β-cyclodextrin-silica derivative under the alkaline condition by one-step polymerization reaction. The β-Cyclodextrin-silica hybrid chiral stationary phases could be directly used as high performance liquid chromatographic packings after the template removal. The hybrid materials prepared in this paper possessed regular spherical morphology, good monodispersion, high specific surface area, good mechanical property, high chemical stability and simple preparation process. It combined the chiral recognition performance of β-cyclodextrin and the outstanding performance of organic-inorganic hybrid material. The effect of the composition, ratio and pH of mobile phase on chiral separation was investigated, and the best chiral separation conditions had been optimized. The baseline chiral separations for five chiral compounds were obtained under the optimal conditions. The results of enantioseparation showed that the hybrid chiral stationary phases had favorable chiral recognition ability. Compared with the traditional preparation process of chiral stationary phases, a new thought for new type of chiral stationary phase is provided by the present method in this paper.
2016, 34(1): 96-102
doi: 10.3724/SP.J.1123.2015.06038
Abstract:
Cyclodextrin (CD) based chiral stationary phases (CSPs) have simulated great attention due to their unique chiral recognition ability. Functionalized cyclodextrins bonded silica gel as chiral stationary phases have been dramatically developed due to their chemical stability and solvent tolerability. To explore the functionalization of phenylcarbamoylated β-cyclodextrin CSPs on their enantioselectivities, 4-chloro-3-methylaniline and 5-chloro-2-methyl phenyl isocyanate were employed. Two CSPs have been thus developed by clicking the CD derivatives onto alkynylated silica support. They include per-4-chloro-3-methylphenylcarbamoylated β-cyclodextrin clicked CSP (CSP1) and per-5-chloro-2-methylphenylcarbamoylated β-cyclodextrin clicked CSP (CSP2), which have both electron-donating (methyl) and withdrawing (chlorine) groups in the phenylcarbamate moieties, but different locations. The CSPs were successfully characterized in terms of structure using nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR) and elementary analysis. Their enantioselectivities wereevaluated in reversed-phase high performance liquid chromatography (HPLC). The comparison study on the enantioseparation of nine flavonoids with the two CSPs demonstrates the higher enantioselectivities of CSP1 over CSP2, because of the different locations of electron-donating (methyl) and withdrawing (chlorine) groups in the phenylcarbamate moieties of CD derivatives. The baseline enantioseparations achieved in water/methanol as mobile phase offered great potential for the CSPs to be used in practical application.
Cyclodextrin (CD) based chiral stationary phases (CSPs) have simulated great attention due to their unique chiral recognition ability. Functionalized cyclodextrins bonded silica gel as chiral stationary phases have been dramatically developed due to their chemical stability and solvent tolerability. To explore the functionalization of phenylcarbamoylated β-cyclodextrin CSPs on their enantioselectivities, 4-chloro-3-methylaniline and 5-chloro-2-methyl phenyl isocyanate were employed. Two CSPs have been thus developed by clicking the CD derivatives onto alkynylated silica support. They include per-4-chloro-3-methylphenylcarbamoylated β-cyclodextrin clicked CSP (CSP1) and per-5-chloro-2-methylphenylcarbamoylated β-cyclodextrin clicked CSP (CSP2), which have both electron-donating (methyl) and withdrawing (chlorine) groups in the phenylcarbamate moieties, but different locations. The CSPs were successfully characterized in terms of structure using nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR) and elementary analysis. Their enantioselectivities wereevaluated in reversed-phase high performance liquid chromatography (HPLC). The comparison study on the enantioseparation of nine flavonoids with the two CSPs demonstrates the higher enantioselectivities of CSP1 over CSP2, because of the different locations of electron-donating (methyl) and withdrawing (chlorine) groups in the phenylcarbamate moieties of CD derivatives. The baseline enantioseparations achieved in water/methanol as mobile phase offered great potential for the CSPs to be used in practical application.
2016, 34(1): 103-107
doi: 10.3724/SP.J.1123.2015.10013
Abstract:
A method for the separation and determination of optical isomers of phenylephrine was developed based on the promoting effect of non-chiral ionic liquid on chiral ligand-exchange capillary electrophoresis after the electrophoretic parameters were optimized systematically. R-phenylephrine and S-phenylephrine can be separated and determined effectively in 20 mmol/L Tris-H3PO4 buffer solution (pH 5.4) composed of 4.0 mmol/L Cu(Ⅱ), 8.0 mmol/L L-proline (L-Pro) and 15 mmol/L 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) with the applied voltage of 20 kV, capillary temperature of 25 ℃, detection wavelength of 254 nm, and injection of 5 s at 3447 Pa. The resolution of R- and S-phenylephrines was 1.42. The linear ranges for the determination of R-phenylephrine and S-phenylephrine were 12.5-150 mg/L and 15.0-150 mg/L, respectively. The method has been satisfactorily used for the determination of R-phenylephrine and S-phenylephrine in the spiked blood and urine samples. The spiked recoveries in the urine sample were in the range of 93.7%-108.2% with the RSDs lower than 3.18%(n=3), and the spiked recoveries in the blood sample were in the range of 91.4% and 113.1% with the RSDs lower than 4.82%(n=3).
A method for the separation and determination of optical isomers of phenylephrine was developed based on the promoting effect of non-chiral ionic liquid on chiral ligand-exchange capillary electrophoresis after the electrophoretic parameters were optimized systematically. R-phenylephrine and S-phenylephrine can be separated and determined effectively in 20 mmol/L Tris-H3PO4 buffer solution (pH 5.4) composed of 4.0 mmol/L Cu(Ⅱ), 8.0 mmol/L L-proline (L-Pro) and 15 mmol/L 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) with the applied voltage of 20 kV, capillary temperature of 25 ℃, detection wavelength of 254 nm, and injection of 5 s at 3447 Pa. The resolution of R- and S-phenylephrines was 1.42. The linear ranges for the determination of R-phenylephrine and S-phenylephrine were 12.5-150 mg/L and 15.0-150 mg/L, respectively. The method has been satisfactorily used for the determination of R-phenylephrine and S-phenylephrine in the spiked blood and urine samples. The spiked recoveries in the urine sample were in the range of 93.7%-108.2% with the RSDs lower than 3.18%(n=3), and the spiked recoveries in the blood sample were in the range of 91.4% and 113.1% with the RSDs lower than 4.82%(n=3).
2016, 34(1): 108-112
doi: 10.3724/SP.J.1123.2015.10035
Abstract:
Over the past decades, HPLC enantioseparation with chiral stationary phases (CSPs) has been widely applied in chiral analysis and preparation of new pharmaceuticals, pesticides, food, etc. Herein, enantioseparation of 20 chiral compounds have been carried out on three polysaccharide-based CSPs (EnantioPak AD, AS and OD) with normal phases by HPLC, separately. The influences of skeletal structure and the kinds of derivative groups on separation behaviors of these CSPs have been studied in detail. As results indicated, except for compound 13, the other compounds were baseline separated on EnantioPak AD, with most of resolution over 2.0; in addition, better separation for acidic or basic compounds was achieved through adding acidic/basic additives into the mobile phase of hexane-alcohol. For four aromatic alcohols (compounds 13-16), their retention in the EnantioPak AD column showed a weakening tendency with increase of carbon number in side chain group, and the reverse trend of their resolution was observed. Furthermore, EnantioPak AD showed much better separation performance for eight compounds (13-20) than the others. In short, these results have provided some references for further investigation of separation behavior and applications of polysaccharide-based CSPs.
Over the past decades, HPLC enantioseparation with chiral stationary phases (CSPs) has been widely applied in chiral analysis and preparation of new pharmaceuticals, pesticides, food, etc. Herein, enantioseparation of 20 chiral compounds have been carried out on three polysaccharide-based CSPs (EnantioPak AD, AS and OD) with normal phases by HPLC, separately. The influences of skeletal structure and the kinds of derivative groups on separation behaviors of these CSPs have been studied in detail. As results indicated, except for compound 13, the other compounds were baseline separated on EnantioPak AD, with most of resolution over 2.0; in addition, better separation for acidic or basic compounds was achieved through adding acidic/basic additives into the mobile phase of hexane-alcohol. For four aromatic alcohols (compounds 13-16), their retention in the EnantioPak AD column showed a weakening tendency with increase of carbon number in side chain group, and the reverse trend of their resolution was observed. Furthermore, EnantioPak AD showed much better separation performance for eight compounds (13-20) than the others. In short, these results have provided some references for further investigation of separation behavior and applications of polysaccharide-based CSPs.
2016, 34(1): 113-118
doi: 10.3724/SP.J.1123.2015.08001
Abstract:
Metal-organic frameworks (MOFs) as a new generation of functional molecular materials, have broad application prospects in enantioselective catalysis and chiral separation areas due to their unusual properties, such as high surface area, rich topologies, permanent microporous, availability of outer-surface modification and so on. A single-handed helical three-dimensional metal-organic framework material [{Cu(sala)}n] (H2sala=N-(2-hydroxybenzyl)-L-alanine) was incorporated with peramylated β-cyclodextrin for the preparation of novel capillary gas chromatography stationary phase. To investigate whether the use of a chiral MOF can enhance enantioseparation on peramylated β-cyclodextrin, three chiral columns were fabricated using different stationary phases for comparison, including column A ([{Cu(sala)}n]), column B (peramylated β-cyclodextrin) and column C ([{Cu(sala)}n]+peramylated β-cyclodextrin). The results of comparing the resolving abilities of the three columns for the same chiral compounds demonstrated that column C showed better enantioselectivity and higher resolution. The use of MOF [{Cu(sala)}n] can improve enantioseparation on peramylated β-cyclodextrin.
Metal-organic frameworks (MOFs) as a new generation of functional molecular materials, have broad application prospects in enantioselective catalysis and chiral separation areas due to their unusual properties, such as high surface area, rich topologies, permanent microporous, availability of outer-surface modification and so on. A single-handed helical three-dimensional metal-organic framework material [{Cu(sala)}n] (H2sala=N-(2-hydroxybenzyl)-L-alanine) was incorporated with peramylated β-cyclodextrin for the preparation of novel capillary gas chromatography stationary phase. To investigate whether the use of a chiral MOF can enhance enantioseparation on peramylated β-cyclodextrin, three chiral columns were fabricated using different stationary phases for comparison, including column A ([{Cu(sala)}n]), column B (peramylated β-cyclodextrin) and column C ([{Cu(sala)}n]+peramylated β-cyclodextrin). The results of comparing the resolving abilities of the three columns for the same chiral compounds demonstrated that column C showed better enantioselectivity and higher resolution. The use of MOF [{Cu(sala)}n] can improve enantioseparation on peramylated β-cyclodextrin.
2016, 34(2): 140-145
doi: 10.3724/SP.J.1123.2015.10009
Abstract:
Caenorhabditis elegans (C. elegans) has been widely used as a model organism for biomedical research due to its sufficient homology with human at molecular or genomic level. In this work, we describe a microfluidic device not only to investigate the response of C. elegans including lifespan and oxidative stress, but also to evaluate the protective effect of polydatin induced by high-glucose condition. It was found that the mean lifespan of worms was significantly reduced and the oxidative stress protein GST-4 was increased in worms that are subjected to high glucose. However, a certain dose of polydatin could weaken the increased oxidative stress induced by high-glucose and extend the lifespan, indicating the protective effect of polydatin against the toxic of high-glucose. The established approach is simple to operate, easy for realtime imaging and multiparatemer evaluations in parallel, providing a potential platform for drug evaluation/screening in a high throughput format at single animal resolution.
Caenorhabditis elegans (C. elegans) has been widely used as a model organism for biomedical research due to its sufficient homology with human at molecular or genomic level. In this work, we describe a microfluidic device not only to investigate the response of C. elegans including lifespan and oxidative stress, but also to evaluate the protective effect of polydatin induced by high-glucose condition. It was found that the mean lifespan of worms was significantly reduced and the oxidative stress protein GST-4 was increased in worms that are subjected to high glucose. However, a certain dose of polydatin could weaken the increased oxidative stress induced by high-glucose and extend the lifespan, indicating the protective effect of polydatin against the toxic of high-glucose. The established approach is simple to operate, easy for realtime imaging and multiparatemer evaluations in parallel, providing a potential platform for drug evaluation/screening in a high throughput format at single animal resolution.
2016, 34(2): 146-151
doi: 10.3724/SP.J.1123.2015.08021
Abstract:
Gravitational field-flow fractionation is the simplest field-flow fractionation technique in terms of principle and operation. The earth's gravity is its external field. Different sized particles are injected into a thin channel and carried by carrier fluid. The different velocities of the carrier liquid in different places results in a size-based separation. A gravitational field-flow fractionation (GrFFF) instrument was designed and constructed. Two kinds of polystyrene (PS) particles with different sizes (20 μ m and 6 μ m) were chosen as model particles. In this work, the separation of the sample was achieved by changing the concentration of NaN3, the percentage of mixed surfactant in the carrier liquid and the flow rate of carrier liquid. Six levels were set for each factor. The effects of these three factors on the retention ratio (R) and plate height (H) of the PS particles were investigated. It was found that R increased and H decreased with increasing particle size. On the other hand, the R and H increased with increasing flow rate. The R and H also increased with increasing NaN3 concentration. The reason was that the electrostatic repulsive force between the particles and the glass channel wall increased. The force allowed the samples approach closer to the channel wall. The results showed that the resolution and retention time can be improved by adjusting the experimental conditions. These results can provide important values to the further applications of GrFFF technique.
Gravitational field-flow fractionation is the simplest field-flow fractionation technique in terms of principle and operation. The earth's gravity is its external field. Different sized particles are injected into a thin channel and carried by carrier fluid. The different velocities of the carrier liquid in different places results in a size-based separation. A gravitational field-flow fractionation (GrFFF) instrument was designed and constructed. Two kinds of polystyrene (PS) particles with different sizes (20 μ m and 6 μ m) were chosen as model particles. In this work, the separation of the sample was achieved by changing the concentration of NaN3, the percentage of mixed surfactant in the carrier liquid and the flow rate of carrier liquid. Six levels were set for each factor. The effects of these three factors on the retention ratio (R) and plate height (H) of the PS particles were investigated. It was found that R increased and H decreased with increasing particle size. On the other hand, the R and H increased with increasing flow rate. The R and H also increased with increasing NaN3 concentration. The reason was that the electrostatic repulsive force between the particles and the glass channel wall increased. The force allowed the samples approach closer to the channel wall. The results showed that the resolution and retention time can be improved by adjusting the experimental conditions. These results can provide important values to the further applications of GrFFF technique.
2016, 34(2): 152-157
doi: 10.3724/SP.J.1123.2015.08029
Abstract:
Based on the unique molecular structure of ferrocene and its potential as a new liquid chromatography separation medium, a new silica-bonded (4-cyclopentadienyl benzoic acid-iron-toluene) hexafluorophosphoric acid stationary phase was prepared. The structure of this new material was characterized by infrared spectroscopy, elemental analysis, thermogravimetric analysis et al. The chromatographic performance and retention mechanism of this new stationary phase were evaluated using different solute probes, including polycyclic aromatic hydrocarbons (PAHs), positional isomers of naphthylamine, positional isomers of nitro-aniline, nitroimidazoles, organic phosphorus et al. It could provide various action sites for different solutes in normal-phase chromatography such as π electron transfer, π-π electron interactions, dipole-dipole interactions, and electrostatic interactions with the substrates. And the possible separation mechanisms are discussed.
Based on the unique molecular structure of ferrocene and its potential as a new liquid chromatography separation medium, a new silica-bonded (4-cyclopentadienyl benzoic acid-iron-toluene) hexafluorophosphoric acid stationary phase was prepared. The structure of this new material was characterized by infrared spectroscopy, elemental analysis, thermogravimetric analysis et al. The chromatographic performance and retention mechanism of this new stationary phase were evaluated using different solute probes, including polycyclic aromatic hydrocarbons (PAHs), positional isomers of naphthylamine, positional isomers of nitro-aniline, nitroimidazoles, organic phosphorus et al. It could provide various action sites for different solutes in normal-phase chromatography such as π electron transfer, π-π electron interactions, dipole-dipole interactions, and electrostatic interactions with the substrates. And the possible separation mechanisms are discussed.
2016, 34(2): 158-164
doi: 10.3724/SP.J.1123.2015.09026
Abstract:
A multiresidue analytical method for the determination of 250 pesticide residues in vegetables was developed by using QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The target compounds were extracted with acetonitrile containing 1%(v/v) acetic acid, purified by a mixed sorbent of MgSO4, primary secondary amine (PSA), graphitized carbon black (GCB) and C18, separated on a Waters ACQUITYTM UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μ m) and detected by UPLC-MS/MS. Anhydrous magnesium sulfate was used as a dewatering agent. The effects of the amounts of MgSO4, PSA, GCB and C18 added on the recoveries of 250 pesticides were investigated. The results showed that the purification effect was best when 300 mg MgSO4, 200 mg PSA, 10 mg GCB and 100 mg C18 in 2 mL of the extract were added. For the 250 pesticide residues, the limits of detection (LODs) of the method were from 0.01 to 50.00 μ g/kg. The recoveries obtained ranged from 60.1% to 120% at three spiked levels in Chinese chives with the relative standard deviations between 3.5% and 19.5% using matrix matched external standard method. The results showed that the method is able to meet requirements of the multiresidue detection of the 250 pesticides in vegetable. The method has the advantages of rapidity, simplicity, high sensitivity and better purification effect. It is suitable for the rapid determination of the common pesticides in vegetables, and it provides a strong guarantee for the risk assessments of the quality and safety of vegetables.
A multiresidue analytical method for the determination of 250 pesticide residues in vegetables was developed by using QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The target compounds were extracted with acetonitrile containing 1%(v/v) acetic acid, purified by a mixed sorbent of MgSO4, primary secondary amine (PSA), graphitized carbon black (GCB) and C18, separated on a Waters ACQUITYTM UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μ m) and detected by UPLC-MS/MS. Anhydrous magnesium sulfate was used as a dewatering agent. The effects of the amounts of MgSO4, PSA, GCB and C18 added on the recoveries of 250 pesticides were investigated. The results showed that the purification effect was best when 300 mg MgSO4, 200 mg PSA, 10 mg GCB and 100 mg C18 in 2 mL of the extract were added. For the 250 pesticide residues, the limits of detection (LODs) of the method were from 0.01 to 50.00 μ g/kg. The recoveries obtained ranged from 60.1% to 120% at three spiked levels in Chinese chives with the relative standard deviations between 3.5% and 19.5% using matrix matched external standard method. The results showed that the method is able to meet requirements of the multiresidue detection of the 250 pesticides in vegetable. The method has the advantages of rapidity, simplicity, high sensitivity and better purification effect. It is suitable for the rapid determination of the common pesticides in vegetables, and it provides a strong guarantee for the risk assessments of the quality and safety of vegetables.
2016, 34(2): 165-169
doi: 10.3724/SP.J.1123.2015.08018
Abstract:
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the study of dynamic behavior of aldicarb and its metabolite residues in cabbage. Aldicarb was applied onto cultivated cabbages. The pesticides concentrations were measured periodically (between application and harvest), and modeled to illustrate the dynamic behavior. The results showed that the liner ranges of aldicarb and its metabolites were from 0.005 to 0.2 mg/L, and the recoveries ranged from 78.9% to 108.5% with the relative standard deviations of 2.03%-8.91%(n=8). The aldicarb in cabbage increased at first with the first-order kinetic equation model of c=0.020e0.136t with the correlation coefficient (r2) of 0.888, and then decreased with the equation of c=0.65e-0.059t with the r2 of 0.979 and the half-life of 29.1 d. The reducing processes of aldicarb-sulfone and aldicarb-sulfoxide both matched the first-order kinetic equations (c=23.4e-0.044t and c=4.54e-0.027t) with r2 of 0.916 and 0.972 respectively. To meet the limitation requirement of 0.01 mg/kg, 70.7, 226.6 and 176.3 d were respectively necessary for aldicarb, aldicarb-sulfone and aldicarb-sulfoxide. Final residues of aldicarb-sulfone and aldicarb-sulfoxide were still more than the limitation requirements, indicating that aldicarb should not be used in vegetables of growth cycle shorter than 120 d. This study provided theoretical basis for dynamic behavior of aldicarb residue and its safe use in vegetables.
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the study of dynamic behavior of aldicarb and its metabolite residues in cabbage. Aldicarb was applied onto cultivated cabbages. The pesticides concentrations were measured periodically (between application and harvest), and modeled to illustrate the dynamic behavior. The results showed that the liner ranges of aldicarb and its metabolites were from 0.005 to 0.2 mg/L, and the recoveries ranged from 78.9% to 108.5% with the relative standard deviations of 2.03%-8.91%(n=8). The aldicarb in cabbage increased at first with the first-order kinetic equation model of c=0.020e0.136t with the correlation coefficient (r2) of 0.888, and then decreased with the equation of c=0.65e-0.059t with the r2 of 0.979 and the half-life of 29.1 d. The reducing processes of aldicarb-sulfone and aldicarb-sulfoxide both matched the first-order kinetic equations (c=23.4e-0.044t and c=4.54e-0.027t) with r2 of 0.916 and 0.972 respectively. To meet the limitation requirement of 0.01 mg/kg, 70.7, 226.6 and 176.3 d were respectively necessary for aldicarb, aldicarb-sulfone and aldicarb-sulfoxide. Final residues of aldicarb-sulfone and aldicarb-sulfoxide were still more than the limitation requirements, indicating that aldicarb should not be used in vegetables of growth cycle shorter than 120 d. This study provided theoretical basis for dynamic behavior of aldicarb residue and its safe use in vegetables.
2016, 34(2): 170-175
doi: 10.3724/SP.J.1123.2015.08033
Abstract:
An analytical method was developed to simultaneously determine the residues of four β2-agonists in animal foods by high performance liquid chromatography/electrospray-tandem mass spectrometry (HPLC-MS/MS). Samples were extracted with 5% (mass fraction) trichloracetic acid, and then cleaned up by two solid phase extraction cartridges (HLB and ProElut PXC). Quantification of the four β2-agonists was achieved by HPLC-MS/MS in multiple reaction monitoring (MRM) using internal standard method. The limits of detection (S/N=3) of clenbuterol, salbutamol, ractopamine and terbutaline were 0.05, 0.05, 0.05 and 0.2 μ g/kg, and the limits of quantification (S/N=10) were 0.25, 0.25, 0.1 and 0.5 μ g/kg, respectively. The average recoveries of the four β2-agonists spiked in blank samples at the spiked levels of 2.5, 5 and 10 μ g/kg were 90.3%-120.5% with the relative standard deviation (RSD) range of 1.60%-9.33%. The method is reliable, sensitive, good recovery and repeatability. It is suitable for the determination of the residues of the four β2-agonists in animal foods.
An analytical method was developed to simultaneously determine the residues of four β2-agonists in animal foods by high performance liquid chromatography/electrospray-tandem mass spectrometry (HPLC-MS/MS). Samples were extracted with 5% (mass fraction) trichloracetic acid, and then cleaned up by two solid phase extraction cartridges (HLB and ProElut PXC). Quantification of the four β2-agonists was achieved by HPLC-MS/MS in multiple reaction monitoring (MRM) using internal standard method. The limits of detection (S/N=3) of clenbuterol, salbutamol, ractopamine and terbutaline were 0.05, 0.05, 0.05 and 0.2 μ g/kg, and the limits of quantification (S/N=10) were 0.25, 0.25, 0.1 and 0.5 μ g/kg, respectively. The average recoveries of the four β2-agonists spiked in blank samples at the spiked levels of 2.5, 5 and 10 μ g/kg were 90.3%-120.5% with the relative standard deviation (RSD) range of 1.60%-9.33%. The method is reliable, sensitive, good recovery and repeatability. It is suitable for the determination of the residues of the four β2-agonists in animal foods.
2016, 34(2): 176-183
doi: 10.3724/SP.J.1123.2015.09021
Abstract:
A method has been developed for the simultaneous determination of 23 antibiotics (four categories) and 3 β-agonists in livestock drinking water using solid-phase extraction and ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI MS/MS). The samples were adjusted pH to 5.0, added Na2EDTA, enriched and cleaned-up by an HLB solid-phase extraction cartridge. The target compounds were confirmed and quantified by UPLC-ESI MS/MS with external standard method for the antibiotics and internal standard method for the β-agonists. The recoveries were assessed by using lab tap water as matrix. The average recoveries of the 23 antibiotics and the 3 β-agonists were in the range of 50.7%-104.6% and the relative standard deviations (RSDs) were 2.6%-8.8%(n=3). Under the optimal conditions, the calibration curves of the 23 antibiotics and the 3 β-agonists showed good linearity with the correlation coefficients better than 0.994. The limits of detection (LODs, S/N≥3) ranged from 0.01-0.20 ng/L. The developed method was applied to analyze the livestock drinking waters in 36 Beijing intensive livestock farms. The results showed that some antibiotics were detected.
A method has been developed for the simultaneous determination of 23 antibiotics (four categories) and 3 β-agonists in livestock drinking water using solid-phase extraction and ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI MS/MS). The samples were adjusted pH to 5.0, added Na2EDTA, enriched and cleaned-up by an HLB solid-phase extraction cartridge. The target compounds were confirmed and quantified by UPLC-ESI MS/MS with external standard method for the antibiotics and internal standard method for the β-agonists. The recoveries were assessed by using lab tap water as matrix. The average recoveries of the 23 antibiotics and the 3 β-agonists were in the range of 50.7%-104.6% and the relative standard deviations (RSDs) were 2.6%-8.8%(n=3). Under the optimal conditions, the calibration curves of the 23 antibiotics and the 3 β-agonists showed good linearity with the correlation coefficients better than 0.994. The limits of detection (LODs, S/N≥3) ranged from 0.01-0.20 ng/L. The developed method was applied to analyze the livestock drinking waters in 36 Beijing intensive livestock farms. The results showed that some antibiotics were detected.
2016, 34(2): 184-188
doi: 10.3724/SP.J.1123.2015.08027
Abstract:
An analytical method was developed for the determination of ginkgolic acids in ginkgo biloba extract and its preparations by ultra high performance liquid chromatography-triple quadrupole mass spectrometry. A chromatographic column, Agilent Poroshell 120 EC-C18(50 mm×3.0 mm, 2.7 μ m), was used with methanol-1% acetic acid (90 : 10, v/v) as the mobile phase. The ginkgo acids were detected by electrospray ionization mass spectrometry in negative mode with multiple reaction monitoring (MRM) mode. Ginkgo acids C13 : 0, C15 : 1 and C17 : 1 possessed good linear correlations in the mass concentration range from 2 to 200 μ g/L, with the correlation coefficients more than 0.999. The mean recoveries at the spiked levels of 5, 20 and 100 μ g/L were in the range of 86.3%-114.3%, and the RSDs were 0.5%-13.6%. The limits of detection and quantification were 0.003-0.08 μ g/g and 0.01-0.19 μ g/g, respectively. The method was successfully applied to the analysis of actual samples.
An analytical method was developed for the determination of ginkgolic acids in ginkgo biloba extract and its preparations by ultra high performance liquid chromatography-triple quadrupole mass spectrometry. A chromatographic column, Agilent Poroshell 120 EC-C18(50 mm×3.0 mm, 2.7 μ m), was used with methanol-1% acetic acid (90 : 10, v/v) as the mobile phase. The ginkgo acids were detected by electrospray ionization mass spectrometry in negative mode with multiple reaction monitoring (MRM) mode. Ginkgo acids C13 : 0, C15 : 1 and C17 : 1 possessed good linear correlations in the mass concentration range from 2 to 200 μ g/L, with the correlation coefficients more than 0.999. The mean recoveries at the spiked levels of 5, 20 and 100 μ g/L were in the range of 86.3%-114.3%, and the RSDs were 0.5%-13.6%. The limits of detection and quantification were 0.003-0.08 μ g/g and 0.01-0.19 μ g/g, respectively. The method was successfully applied to the analysis of actual samples.
2016, 34(2): 189-193
doi: 10.3724/SP.J.1123.2015.08017
Abstract:
New methods were developed for the determination of succinic acid in desvenlafaxine succinate (DVS) by high performance ion-exclusion chromatography (HPIEC) and high performance ion-exchange chromatography (HPIC). HPIEC and HPIC methods were used separately to determinate the succinic acid in DVS. With HPIEC, the sample was diluted with 2.50×10-3mol/L sulfuric acid solution and filtrated by 0.22 μ m polyether sulfone filter membrane, and then analyzed by HPIEC directly without any further pretreatment. The analytical column was Phenomenex Rezex ROA-organic Acid H+(8%)(300 mm×7.8 mm). The mobile phase was 2.50×10-3mol/L sulfuric acid solution at the flow rate of 0.5 mL/min. The column temperature was set at 40 ℃, and the detection wavelength was 210 nm. The injection volume was 10 μ L. The assay was quantified by external standard method. With HPIC, the sample was diluted with ultrapure water and filtrated by 0.22 μ m polyether sulfone filter membrane, and then analyzed by HPIC directly without any further pretreatment. The analytical column was Dionex IonPac AS11-HC (250 mm×4 mm) with a guard column IonPacAG11-HC (50 mm×4 mm). Isocratic KOH elute generator was used at the flow rate of 1.0 mL/min. The detection was performed by a Dionex suppressed (DIONEX AERS 500 4-mm) conductivity detector. The injection volume was 10 μ L. The content computation was performed with peak area external reference method. The results of HPIEC method for succinic acid were 28.8%, 28.9% and 28.9%, while the results of HPIEC method were 28.2%, 28.6% and 28.6%. The results of HPIEC and HPIC methods were not significantly different. The two methods can both be used to determine the contents of succinic acid in DVS. The surveillance analytical method should be chosen according to the situation.
New methods were developed for the determination of succinic acid in desvenlafaxine succinate (DVS) by high performance ion-exclusion chromatography (HPIEC) and high performance ion-exchange chromatography (HPIC). HPIEC and HPIC methods were used separately to determinate the succinic acid in DVS. With HPIEC, the sample was diluted with 2.50×10-3mol/L sulfuric acid solution and filtrated by 0.22 μ m polyether sulfone filter membrane, and then analyzed by HPIEC directly without any further pretreatment. The analytical column was Phenomenex Rezex ROA-organic Acid H+(8%)(300 mm×7.8 mm). The mobile phase was 2.50×10-3mol/L sulfuric acid solution at the flow rate of 0.5 mL/min. The column temperature was set at 40 ℃, and the detection wavelength was 210 nm. The injection volume was 10 μ L. The assay was quantified by external standard method. With HPIC, the sample was diluted with ultrapure water and filtrated by 0.22 μ m polyether sulfone filter membrane, and then analyzed by HPIC directly without any further pretreatment. The analytical column was Dionex IonPac AS11-HC (250 mm×4 mm) with a guard column IonPacAG11-HC (50 mm×4 mm). Isocratic KOH elute generator was used at the flow rate of 1.0 mL/min. The detection was performed by a Dionex suppressed (DIONEX AERS 500 4-mm) conductivity detector. The injection volume was 10 μ L. The content computation was performed with peak area external reference method. The results of HPIEC method for succinic acid were 28.8%, 28.9% and 28.9%, while the results of HPIEC method were 28.2%, 28.6% and 28.6%. The results of HPIEC and HPIC methods were not significantly different. The two methods can both be used to determine the contents of succinic acid in DVS. The surveillance analytical method should be chosen according to the situation.
2016, 34(2): 194-201
doi: 10.3724/SP.J.1123.2015.07021
Abstract:
A rapid determination method of 21 organophosphorus pesticides in tea was developed by QuEChERS method using modified multi-walled carbon nanotubes (MWCNTs-OH), primary-secondary amine (PSA) and MgSO4 coupled with gas chromatography-mass spectrometry. The pesticide residues in tea were extracted with a hexane-acetone (2 : 1, v/v) mixture, and cleaned up by dispersive solid-phase extraction using MWCNTs-OH and primary-secondary amine (PSA) as the sorbents. After centrifugation and filtration, the target compounds were analyzed by gas chromatography-mass spectrometry and quantified by the external standard method. Under the optimized conditions, good linearities were obtained in the range of 0.01-0.50 mg/kg. The average recoveries were in the range of 81.5%-109.4% at three spiked levels, with relative standard deviations (RSDs, n=5) of 2.3%-10.6%. The limits of quantification were 0.001-0.040 mg/kg. This method is simple, fast, sensitive, cheap, and can meet the requirements of the rapid detection of organophosphorus pesticides in tea.
A rapid determination method of 21 organophosphorus pesticides in tea was developed by QuEChERS method using modified multi-walled carbon nanotubes (MWCNTs-OH), primary-secondary amine (PSA) and MgSO4 coupled with gas chromatography-mass spectrometry. The pesticide residues in tea were extracted with a hexane-acetone (2 : 1, v/v) mixture, and cleaned up by dispersive solid-phase extraction using MWCNTs-OH and primary-secondary amine (PSA) as the sorbents. After centrifugation and filtration, the target compounds were analyzed by gas chromatography-mass spectrometry and quantified by the external standard method. Under the optimized conditions, good linearities were obtained in the range of 0.01-0.50 mg/kg. The average recoveries were in the range of 81.5%-109.4% at three spiked levels, with relative standard deviations (RSDs, n=5) of 2.3%-10.6%. The limits of quantification were 0.001-0.040 mg/kg. This method is simple, fast, sensitive, cheap, and can meet the requirements of the rapid detection of organophosphorus pesticides in tea.
2016, 34(2): 202-208
doi: 10.3724/SP.J.1123.2015.08032
Abstract:
An analytical method for quantifying short-chain chlorinated paraffins (SCCPs) in ambient air using high-volume sampling combined with high resolution gas chromatography-electron capture negative ion-low resolution mass spectrometry (HRGC-ECNI-LRMS) was developed. An acidified silica gel column and a basic alumina column were used to optimize the cleanup procedures. The results showed a good linearity (R2＞0.99) between the total response factors and the degree of chlorination of SCCPs in the content range of 58.1%-63.3%. The limits of detection (S/N≥3) and the limits of quantification (S/N≥10) were 4.2 and 12 pg, respectively. The method detection limit (MDL) for SCCPs was 0.34ng/m3 (n=7). The recoveries of SCCPs in air samples were in the range of 81.9% to 94.2%. It is demonstrated that the method is suitable for the quantitative analysis of SCCPs in air samples.
An analytical method for quantifying short-chain chlorinated paraffins (SCCPs) in ambient air using high-volume sampling combined with high resolution gas chromatography-electron capture negative ion-low resolution mass spectrometry (HRGC-ECNI-LRMS) was developed. An acidified silica gel column and a basic alumina column were used to optimize the cleanup procedures. The results showed a good linearity (R2＞0.99) between the total response factors and the degree of chlorination of SCCPs in the content range of 58.1%-63.3%. The limits of detection (S/N≥3) and the limits of quantification (S/N≥10) were 4.2 and 12 pg, respectively. The method detection limit (MDL) for SCCPs was 0.34ng/m3 (n=7). The recoveries of SCCPs in air samples were in the range of 81.9% to 94.2%. It is demonstrated that the method is suitable for the quantitative analysis of SCCPs in air samples.
2016, 34(2): 209-214
doi: 10.3724/SP.J.1123.2015.09023
Abstract:
A method was established for the simultaneous determination of 23 volatile organic compounds (VOCs) in ambient air with combination of thermal desorption (TD) and gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS). The air samples were collected by active sampling method using Tenax-TA sorbent tubes, and desorbed by thermal desorption. The analytes were determined by GC-MS/MS in selected reaction monitoring (SRM) mode, and internal standard method was applied to quantify the VOCs. The results of all the 23 VOCs showed good linearities in low level (0.01-1 ng) and high level (1-100 ng) with all the correlation coefficients (r2) more than 0.99. The method quantification limits were between 0.00008-1 μ g/m3. The method was validated by means of recovery experiments (n=6) at three spiked levels of 2, 10 and 50 ng. The recoveries between 77% and 124% were generally obtained. The relative standard deviations (RSDs) in all cases were lower than 20%, except for chlorobenzene at the low spiked level. The developed method was applied to determine VOCs in ambient air collected at three sites in Shanghai. Several compounds, like benzene, toluene, ethylbenzene, m-xylenes, p-xylenes, styrene, 1,2,4-trimethylbenzene and hexachlorobutadiene were detected and confirmed in all the samples analyzed. The method is highly accurate, reliable and sensitive for monitoring the VOCs in ambient air.
A method was established for the simultaneous determination of 23 volatile organic compounds (VOCs) in ambient air with combination of thermal desorption (TD) and gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS). The air samples were collected by active sampling method using Tenax-TA sorbent tubes, and desorbed by thermal desorption. The analytes were determined by GC-MS/MS in selected reaction monitoring (SRM) mode, and internal standard method was applied to quantify the VOCs. The results of all the 23 VOCs showed good linearities in low level (0.01-1 ng) and high level (1-100 ng) with all the correlation coefficients (r2) more than 0.99. The method quantification limits were between 0.00008-1 μ g/m3. The method was validated by means of recovery experiments (n=6) at three spiked levels of 2, 10 and 50 ng. The recoveries between 77% and 124% were generally obtained. The relative standard deviations (RSDs) in all cases were lower than 20%, except for chlorobenzene at the low spiked level. The developed method was applied to determine VOCs in ambient air collected at three sites in Shanghai. Several compounds, like benzene, toluene, ethylbenzene, m-xylenes, p-xylenes, styrene, 1,2,4-trimethylbenzene and hexachlorobutadiene were detected and confirmed in all the samples analyzed. The method is highly accurate, reliable and sensitive for monitoring the VOCs in ambient air.
2016, 34(2): 215-221
doi: 10.3724/SP.J.1123.2015.09006
Abstract:
The identification of isoparaffin components in petroleum middle fractions including kerosene and diesel fuels was investigated by gas chromatography-mass spectrometry (GC/MS). The isodewaxing middle fraction and distilled diesel were selected as the objective samples for identification. It was shown that the isoparaffin components in middle fraction were well separated with their branched alkyl substituent numbers on a capillary chromatographic column in selected ion monitoring (SIM) mode of GC/MS. The identification for C10-C24 isoparaffins was realized with the technique of GC/MS, such as the fragmentation pathways of electron ionization and SIM technique, boiling point rule, published retention indices and theoretical rules about component retention behavior in GC including carbon number rule etc. Finally, the retention indices for the mono-substituted, di-substituted and multi-substituted isoparaffins from C10 to C24 were presented, which could provide an overall knowledge of isoparaffin distribution at carbon number level in fuels. Meanwhile, the peaks that could be well resolved in each isoparaffin group were also identified, and the detailed data for about 80 C10-C21 methyl-substituted isoparaffins and isoprenoid biomarkers were also given. The results showed that in isodewaxing middle fraction studied, the mono-substituted and di-substituted isoparaffins were the main paraffins, whereas in distilled diesel studies, the mono-substituted isoparaffins and isoprenoid biomarkers were the main ones.
The identification of isoparaffin components in petroleum middle fractions including kerosene and diesel fuels was investigated by gas chromatography-mass spectrometry (GC/MS). The isodewaxing middle fraction and distilled diesel were selected as the objective samples for identification. It was shown that the isoparaffin components in middle fraction were well separated with their branched alkyl substituent numbers on a capillary chromatographic column in selected ion monitoring (SIM) mode of GC/MS. The identification for C10-C24 isoparaffins was realized with the technique of GC/MS, such as the fragmentation pathways of electron ionization and SIM technique, boiling point rule, published retention indices and theoretical rules about component retention behavior in GC including carbon number rule etc. Finally, the retention indices for the mono-substituted, di-substituted and multi-substituted isoparaffins from C10 to C24 were presented, which could provide an overall knowledge of isoparaffin distribution at carbon number level in fuels. Meanwhile, the peaks that could be well resolved in each isoparaffin group were also identified, and the detailed data for about 80 C10-C21 methyl-substituted isoparaffins and isoprenoid biomarkers were also given. The results showed that in isodewaxing middle fraction studied, the mono-substituted and di-substituted isoparaffins were the main paraffins, whereas in distilled diesel studies, the mono-substituted isoparaffins and isoprenoid biomarkers were the main ones.
2016, 34(2): 121-129
doi: 10.3724/SP.J.1123.2016.01007
Abstract:
This paper reviews the capillary electrophoresis (CE) in 2015. The literatures searched from ISI Web of Science ranged in 2015.1.1-2015.12.31 are classified and introduced based on CE-MS method, methodology research, detection and enrichment, chiral separation and basic applications of CE. Six international and two national conferences are included and the important reports are introduced briefly. In the end, the standards of CE method for the analyses of monoclonal antibodies, water, wines and food approved in China and some other countries are listed.
This paper reviews the capillary electrophoresis (CE) in 2015. The literatures searched from ISI Web of Science ranged in 2015.1.1-2015.12.31 are classified and introduced based on CE-MS method, methodology research, detection and enrichment, chiral separation and basic applications of CE. Six international and two national conferences are included and the important reports are introduced briefly. In the end, the standards of CE method for the analyses of monoclonal antibodies, water, wines and food approved in China and some other countries are listed.
