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2019 Volume 37 Issue 9
2019, 37(9): 925-931
doi: 10.3724/SP.J.1123.2019.01036
Abstract:
Reproduction is one of the most basic characteristics of organisms, and the guarantee of the continuation and evolution of a species. As the country with world's largest population, China has been gradually increasing its investment in research on the reproductive system in recent years, particularly in the field of basic research. The rapid development and wide application of the microfluidic technology since its birth are sufficient to explain its application prospect. Currently, infertility and birth defects are major problems in the field of reproduction. Micro-reproductive technologies, including microfluidic and organs-on-chips, are formed through the combination of a wide range of basic science and bioengineering technologies. In reproductive research, microfluidic technology display several advantages:flexible design of the microchannel shape and size to better simulate the physiological environment, the low consumption of microfluidic chip, and highly integrated microfluidic technology. Microfluidic technology has been applied to various processes including sperm vitality evaluation and screening, sperm chemotaxis, cumulus oophorus cell removal, zona pellucida removal, ootid localization and screening, fertilization, early embryo culture and reproductive organ simulation. This paper introduces the recent progress in reproductive research based on microfluidic technology and its application prospects.
Reproduction is one of the most basic characteristics of organisms, and the guarantee of the continuation and evolution of a species. As the country with world's largest population, China has been gradually increasing its investment in research on the reproductive system in recent years, particularly in the field of basic research. The rapid development and wide application of the microfluidic technology since its birth are sufficient to explain its application prospect. Currently, infertility and birth defects are major problems in the field of reproduction. Micro-reproductive technologies, including microfluidic and organs-on-chips, are formed through the combination of a wide range of basic science and bioengineering technologies. In reproductive research, microfluidic technology display several advantages:flexible design of the microchannel shape and size to better simulate the physiological environment, the low consumption of microfluidic chip, and highly integrated microfluidic technology. Microfluidic technology has been applied to various processes including sperm vitality evaluation and screening, sperm chemotaxis, cumulus oophorus cell removal, zona pellucida removal, ootid localization and screening, fertilization, early embryo culture and reproductive organ simulation. This paper introduces the recent progress in reproductive research based on microfluidic technology and its application prospects.
2019, 37(9): 932-938
doi: 10.3724/SP.J.1123.2019.03005
Abstract:
A novel magnetic surface molecularly imprinted adsorbent is described. Fe3O4@SiO2, tilmicosin, and methacrylic acid were chosen as the support substrate, template molecule, and functional monomer, respectively. 3-Methacryloxypropyltrimethoxysilane was chemically bonded onto the surface of Fe3O4@SiO2 via a silanization reaction and used as the crosslinking agent in the subsequent reaction. The obtained magnetic surface molecularly imprinted polymer (MS-MIP) showed high selectivity and high enrichment capacity towards macrolide antibiotics (MACs), as indicated by the 212-, 275-, 675-, and 293-fold enrichment factors for spiramycin, josamycin, tilmicosin, and tylosin tartrate, separately. Because of the marked cavities onto the surface of the MS-MIP, the time required to reach adsorption equilibrium (30 min) was shorter than that for traditional MIP sorbents. Moreover, the adsorbent could be reused at least 6 times. Finally, the MS-MIP was used in combination with high performance liquid chromatography-ultraviolet detection (HPLC-UV) for the extraction and enrichment of four MACs in milk powder samples. The limits of detection (LODs) and limits of quantitation (LOQs) for the four MACs were in the range of 0.58-1.36 μg/kg and 1.92-4.55 μg/kg, respectively. The interday (n=5) and intraday (n=3) recoveries were in the range of 83.2%-123.0% at three spiked levels of 80, 200, and 500 μg/kg, under all the experimental conditions employed, and the relative standard deviations were less than 12.2%.
A novel magnetic surface molecularly imprinted adsorbent is described. Fe3O4@SiO2, tilmicosin, and methacrylic acid were chosen as the support substrate, template molecule, and functional monomer, respectively. 3-Methacryloxypropyltrimethoxysilane was chemically bonded onto the surface of Fe3O4@SiO2 via a silanization reaction and used as the crosslinking agent in the subsequent reaction. The obtained magnetic surface molecularly imprinted polymer (MS-MIP) showed high selectivity and high enrichment capacity towards macrolide antibiotics (MACs), as indicated by the 212-, 275-, 675-, and 293-fold enrichment factors for spiramycin, josamycin, tilmicosin, and tylosin tartrate, separately. Because of the marked cavities onto the surface of the MS-MIP, the time required to reach adsorption equilibrium (30 min) was shorter than that for traditional MIP sorbents. Moreover, the adsorbent could be reused at least 6 times. Finally, the MS-MIP was used in combination with high performance liquid chromatography-ultraviolet detection (HPLC-UV) for the extraction and enrichment of four MACs in milk powder samples. The limits of detection (LODs) and limits of quantitation (LOQs) for the four MACs were in the range of 0.58-1.36 μg/kg and 1.92-4.55 μg/kg, respectively. The interday (n=5) and intraday (n=3) recoveries were in the range of 83.2%-123.0% at three spiked levels of 80, 200, and 500 μg/kg, under all the experimental conditions employed, and the relative standard deviations were less than 12.2%.
2019, 37(9): 939-945
doi: 10.3724/SP.J.1123.2019.03002
Abstract:
To investigate the immunomodulatory mechanism of low relative molecular mass seleno-aminopolysaccharide, a metabolomics method based on liquid chromatography-time-of-flight mass spectrometry (LC-TOF-MS) was used to analyze the endogenous metabolites changes in the liver of Acanthopagrus schlegelii. The potential biomarkers were screened using non-targeted mass spectrometry with the XCMSplus software, and the related metabolic pathways were analyzed using MetaboAnalyst3.0 website. The results showed that the liver metabolites in the low relative molecular mass seleno-aminopolysaccharide-fed group were significantly different from those in the blank group. Also, 32 biomarkers were identified. Additionally, low relative molecular mass seleno-aminopolysaccharide could enhance the immune function of Acathopagrus schlegelii via amino acid, nucleotide, and nitrogen metabolism, aminoacyl-transfer ribonucleic acid (tRNA) biosynthesis, and other metabolic pathways. This study therefore provides a scientific basis for elucidating the immunoenhancement mechanism of low relative molecular mass seleno-aminopolysaccharide.
To investigate the immunomodulatory mechanism of low relative molecular mass seleno-aminopolysaccharide, a metabolomics method based on liquid chromatography-time-of-flight mass spectrometry (LC-TOF-MS) was used to analyze the endogenous metabolites changes in the liver of Acanthopagrus schlegelii. The potential biomarkers were screened using non-targeted mass spectrometry with the XCMSplus software, and the related metabolic pathways were analyzed using MetaboAnalyst3.0 website. The results showed that the liver metabolites in the low relative molecular mass seleno-aminopolysaccharide-fed group were significantly different from those in the blank group. Also, 32 biomarkers were identified. Additionally, low relative molecular mass seleno-aminopolysaccharide could enhance the immune function of Acathopagrus schlegelii via amino acid, nucleotide, and nitrogen metabolism, aminoacyl-transfer ribonucleic acid (tRNA) biosynthesis, and other metabolic pathways. This study therefore provides a scientific basis for elucidating the immunoenhancement mechanism of low relative molecular mass seleno-aminopolysaccharide.
2019, 37(9): 946-954
doi: 10.3724/SP.J.1123.2019.02016
Abstract:
A method was established to rapidly determine 20 kinds of veterinary drug residues including three catagories of antibiotics (sulfonamides, quinolones, and chloramphenicols) and two kinds of triphenylmethanes (malachite green (MG) and leucomalachite green (LMG)) in fish and shrimp, based on dispersive solid phase extraction purification-ultra high performance liquid chromatography-tandem mass spectrometry. The samples were first hydrolyzed using a dipotassium hydrogen phosphate solution, and then extracted using acetonitrile. Afterward, the extraction solution was dehydrated and salted out with sodium chloride and condensed to nearly dry using a rotating evaporator. This residue was dissolved in 1.0 mL methanol. The resulting solution was purified by dispersive solid phase extraction method with C18 and PSA sorbents, and filtered through a filter. The target compounds were separated employing a ZORBAX C18 column. The mass spectrometer datas were acquired by multiple reaction monitoring (MRM) of positive and negative modes and quantitated applying the isotope internal standard method. The 20 veterinary drugs showed a good linear relationship in the range of 0.2-300 μg/L. The limits of detection and the limits of quantification were 0.1-0.6 and 0.3-1.8 μg/kg, respectively, while the correlation coefficients were greater than 0.99. The average recoveries at the three spiked levels (1, 5, and 20 times of quantitative limits) ranged between 72.5%-118%, with the relative standard deviations of 1.9%-9.8%. The advantages of method include a simple pretreatment, a high detection efficiency, and a low cost. Moreover, it is suitable for the simultaneous determination of multiple veterinary drug residues in fish and shrimp.
A method was established to rapidly determine 20 kinds of veterinary drug residues including three catagories of antibiotics (sulfonamides, quinolones, and chloramphenicols) and two kinds of triphenylmethanes (malachite green (MG) and leucomalachite green (LMG)) in fish and shrimp, based on dispersive solid phase extraction purification-ultra high performance liquid chromatography-tandem mass spectrometry. The samples were first hydrolyzed using a dipotassium hydrogen phosphate solution, and then extracted using acetonitrile. Afterward, the extraction solution was dehydrated and salted out with sodium chloride and condensed to nearly dry using a rotating evaporator. This residue was dissolved in 1.0 mL methanol. The resulting solution was purified by dispersive solid phase extraction method with C18 and PSA sorbents, and filtered through a filter. The target compounds were separated employing a ZORBAX C18 column. The mass spectrometer datas were acquired by multiple reaction monitoring (MRM) of positive and negative modes and quantitated applying the isotope internal standard method. The 20 veterinary drugs showed a good linear relationship in the range of 0.2-300 μg/L. The limits of detection and the limits of quantification were 0.1-0.6 and 0.3-1.8 μg/kg, respectively, while the correlation coefficients were greater than 0.99. The average recoveries at the three spiked levels (1, 5, and 20 times of quantitative limits) ranged between 72.5%-118%, with the relative standard deviations of 1.9%-9.8%. The advantages of method include a simple pretreatment, a high detection efficiency, and a low cost. Moreover, it is suitable for the simultaneous determination of multiple veterinary drug residues in fish and shrimp.
2019, 37(9): 955-962
doi: 10.3724/SP.J.1123.2019.02014
Abstract:
An improved method to screen 52 pesticide residues in flavored tea using QuEChERS coupled with liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-Q-TOF-MS) has been investigated. The flavored tea was extracted with acetonitrile and purified using by primary secondary amine (PSA), graphitized carbon black (GCB) and C18 sorbent. The resultant residues were then analyzed using LC-Q-TOF-MS. The recoveries of all the pesticides in flavored tea at the four spiked levels of 10, 20, 50 and 100 μg/kg were 70%-120% and the relative standard deviations (RSDs, n=3) were less than 20%. The calibration curves of the 52 pesticide residues had good linear relationships, and the correlation coefficients were more than 0. 99. The screening detection limits (SDLs) and the limits of quantitation (LOQs) for the 52 pesticides were in the range of 0.001-0.01 mg/kg and 0.002-0.02 mg/kg, respectively, which were lower than maximum residue limits standard permitted by the European Union (EU). This method is simple, rapid, reliable, and can meet the requirements for the simultaneous determination of 52 pesticide residues in flavored tea.
An improved method to screen 52 pesticide residues in flavored tea using QuEChERS coupled with liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-Q-TOF-MS) has been investigated. The flavored tea was extracted with acetonitrile and purified using by primary secondary amine (PSA), graphitized carbon black (GCB) and C18 sorbent. The resultant residues were then analyzed using LC-Q-TOF-MS. The recoveries of all the pesticides in flavored tea at the four spiked levels of 10, 20, 50 and 100 μg/kg were 70%-120% and the relative standard deviations (RSDs, n=3) were less than 20%. The calibration curves of the 52 pesticide residues had good linear relationships, and the correlation coefficients were more than 0. 99. The screening detection limits (SDLs) and the limits of quantitation (LOQs) for the 52 pesticides were in the range of 0.001-0.01 mg/kg and 0.002-0.02 mg/kg, respectively, which were lower than maximum residue limits standard permitted by the European Union (EU). This method is simple, rapid, reliable, and can meet the requirements for the simultaneous determination of 52 pesticide residues in flavored tea.
2019, 37(9): 963-968
doi: 10.3724/SP.J.1123.2019.03014
Abstract:
A method for the rapid determination of biotoxin (bongkrekic acid) in the Liushenqu was established using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted with methanol by ultrasonication, then the pH was adjusted to 8 using ammonia. After filtration, the extract was purified using an Oasis Max strong anion exchange resin column. The Waters HSS T3 column (100 mm×2.1 mm, 1.8 μm) was used for the UPLC-MS/MS analysis. The mobile phase was acetonitrile-10 mmol/L ammonium formate solution (containing 0.1% (v/v) formic acid). MS analysis was performed using an electrospray ionization (ESI) source in the negative and multiple reaction monitoring (MRM) modes. Under the optimum conditions, the linear range of bongkrekic acid was 0.5-100 μg/L (correlations coefficient (R2)>0.99). The recoveries of the bongkrekic acid were 80.6%-85.3%. The intra-day and inter-day relative standard deviations (RSDs) were in the range of 4.2%-6.8% and 8.2%-13.2%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were 0.4 μg/kg and 1.2 μg/kg, respectively. The results showed that bongkrekic acid residues were detected in Liushenqu, thereby confirming the supporting role of our method for the risk monitoring of biotoxins in health foods and Chinese herbal medicines. This method is simple, easy, sensitive, and suitable for the determination of the bongkrekic acid residues in Liushenqu.
A method for the rapid determination of biotoxin (bongkrekic acid) in the Liushenqu was established using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted with methanol by ultrasonication, then the pH was adjusted to 8 using ammonia. After filtration, the extract was purified using an Oasis Max strong anion exchange resin column. The Waters HSS T3 column (100 mm×2.1 mm, 1.8 μm) was used for the UPLC-MS/MS analysis. The mobile phase was acetonitrile-10 mmol/L ammonium formate solution (containing 0.1% (v/v) formic acid). MS analysis was performed using an electrospray ionization (ESI) source in the negative and multiple reaction monitoring (MRM) modes. Under the optimum conditions, the linear range of bongkrekic acid was 0.5-100 μg/L (correlations coefficient (R2)>0.99). The recoveries of the bongkrekic acid were 80.6%-85.3%. The intra-day and inter-day relative standard deviations (RSDs) were in the range of 4.2%-6.8% and 8.2%-13.2%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were 0.4 μg/kg and 1.2 μg/kg, respectively. The results showed that bongkrekic acid residues were detected in Liushenqu, thereby confirming the supporting role of our method for the risk monitoring of biotoxins in health foods and Chinese herbal medicines. This method is simple, easy, sensitive, and suitable for the determination of the bongkrekic acid residues in Liushenqu.
2019, 37(9): 969-976
doi: 10.3724/SP.J.1123.2019.02009
Abstract:
A liquid chromatography-Orbitrap high resolution mass spectrometry (LC-HRMS) method and a TraceFinder database were developed for the screening and identification of 15 adulterated weight loss compounds in dietary supplements. The samples were extracted with methanol and filtered through a 0.22 μm microfiltration membrane prior to LC-HRMS analysis. The Full MS/dd-MS2 mode was utilized in both positive and negative ion modes and the collected data were imported into the TraceFinder screening software. The established compound database and screening method were used for rapid, automatic, and high-precision screening to determine if the weight loss compounds were adulterated. The method validation results indicated that all of the analytes showed excellent linear relationships with regression coefficients (r) above 0.998. The recoveries were in the range of 79.7%-95.4% while the precisions ranged from 3.3% to 8.7%. The method and database were used to screen weight loss adulterants in 29 batches of dietary supplements; six batches of samples tested positive for adulterants with the identification of four compounds including sibutramine. This method enables the automatic high-precision screening and identification of adulterants, providing a novel and powerful tool for combating the increasingly rampant occurrence of adulteration in dietary supplements.
A liquid chromatography-Orbitrap high resolution mass spectrometry (LC-HRMS) method and a TraceFinder database were developed for the screening and identification of 15 adulterated weight loss compounds in dietary supplements. The samples were extracted with methanol and filtered through a 0.22 μm microfiltration membrane prior to LC-HRMS analysis. The Full MS/dd-MS2 mode was utilized in both positive and negative ion modes and the collected data were imported into the TraceFinder screening software. The established compound database and screening method were used for rapid, automatic, and high-precision screening to determine if the weight loss compounds were adulterated. The method validation results indicated that all of the analytes showed excellent linear relationships with regression coefficients (r) above 0.998. The recoveries were in the range of 79.7%-95.4% while the precisions ranged from 3.3% to 8.7%. The method and database were used to screen weight loss adulterants in 29 batches of dietary supplements; six batches of samples tested positive for adulterants with the identification of four compounds including sibutramine. This method enables the automatic high-precision screening and identification of adulterants, providing a novel and powerful tool for combating the increasingly rampant occurrence of adulteration in dietary supplements.
2019, 37(9): 977-982
doi: 10.3724/SP.J.1123.2019.01054
Abstract:
A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was established for the determination of ten alkaloids in cosmetics. Extraction conditions, purification methods and instrumental parameters were optimized. The samples were ultrasonically extracted with 80% (v/v) methanol aqueous solution. The extracts were separated and filtered after centrifugation. The analytes were separated on a Waters BEH C18 column, and detected in the selected reaction monitoring mode. Ten alkaloids were quantified by the external standard method. The ten alkaloids showed good linearity with correlation coefficients (R2) greater than 0.9900. The limits of detection (LODs) and the limits of quantification (LOQs) of the ten alkaloids were in range of 5.0-12.5 μg/kg and 12.5-50.0 μg/kg, respectively. The average spiked recoveries in the cosmetics ranged from 70.91% to 116.75%, and the relative standard deviations (RSDs) ranged from 0.49% to 9.98%. The method can be used for the rapid screening and quantitative analysis of ten alkaloids in cosmetics.
A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was established for the determination of ten alkaloids in cosmetics. Extraction conditions, purification methods and instrumental parameters were optimized. The samples were ultrasonically extracted with 80% (v/v) methanol aqueous solution. The extracts were separated and filtered after centrifugation. The analytes were separated on a Waters BEH C18 column, and detected in the selected reaction monitoring mode. Ten alkaloids were quantified by the external standard method. The ten alkaloids showed good linearity with correlation coefficients (R2) greater than 0.9900. The limits of detection (LODs) and the limits of quantification (LOQs) of the ten alkaloids were in range of 5.0-12.5 μg/kg and 12.5-50.0 μg/kg, respectively. The average spiked recoveries in the cosmetics ranged from 70.91% to 116.75%, and the relative standard deviations (RSDs) ranged from 0.49% to 9.98%. The method can be used for the rapid screening and quantitative analysis of ten alkaloids in cosmetics.
2019, 37(9): 983-989
doi: 10.3724/SP.J.1123.2019.02013
Abstract:
In this study, a fast and efficient method for the separation and analysis of the products in the acid-catalyzed depolymerization of commercially available sodium lignosulfonate has been developed. The depolymerized lignosulfonate products were well separated and characterized by advanced polymer chromatography (APC) employing four ACQUITY APC XT columns in series and a ultraviolet detector. The developed method enabled the detection of relative-low-molecular-mass lignin degradation products with peak molecular weights (Mp) of 720, 490, and 260 Da, and an extremely low polydispersity index (PDI) of 1, indicating almost complete conversion of lignosulfonate to smaller molecules. The effects of reaction temperature, time, and catalyst/lignin ratio on the reaction products were systematically investigated. High yields of depolymerization (>80%) could be obtained under the mild acid-catalyzed conditions at 130℃ for 60 min using a catalyst/lignin ratio of 2.334:1. Preliminary studies also indicated that the mild acid-catalytic mechanism is unaffected by the reaction time, temperature, or catalyst concentration, thus suggesting the specificity of the catalytic procedure employed.
In this study, a fast and efficient method for the separation and analysis of the products in the acid-catalyzed depolymerization of commercially available sodium lignosulfonate has been developed. The depolymerized lignosulfonate products were well separated and characterized by advanced polymer chromatography (APC) employing four ACQUITY APC XT columns in series and a ultraviolet detector. The developed method enabled the detection of relative-low-molecular-mass lignin degradation products with peak molecular weights (Mp) of 720, 490, and 260 Da, and an extremely low polydispersity index (PDI) of 1, indicating almost complete conversion of lignosulfonate to smaller molecules. The effects of reaction temperature, time, and catalyst/lignin ratio on the reaction products were systematically investigated. High yields of depolymerization (>80%) could be obtained under the mild acid-catalyzed conditions at 130℃ for 60 min using a catalyst/lignin ratio of 2.334:1. Preliminary studies also indicated that the mild acid-catalytic mechanism is unaffected by the reaction time, temperature, or catalyst concentration, thus suggesting the specificity of the catalytic procedure employed.
2019, 37(9): 990-995
doi: 10.3724/SP.J.1123.2019.03026
Abstract:
A rapid method based on ultra-performance convergence chromatography (UPC2) was developed for the analysis of 13 ultraviolet (UV) absorbents in plastic food contact materials. The UV absorbents were extracted from plastic food contact materials by supersonic extraction with methanol, purified by C18 solid phase extraction column, and analyzed via UPC2 before filtration with an organic filtration membrane (0.22 μm). An ACQUTY UPC2 HSS C18 SB chromatographic column (150 mm×3.0 mm, 1.8 μm) was used for the detection of the UV absorbents. An effective separation was achieved within 4 min under the optimized conditions. The mobile phases were supercritical carbon dioxide and isopropanol as a modifier. The results showed that the 13 UV absorbents exhibited good linear relationships in the respective linear ranges with the correlation coefficients no less than 0.9985. The limits of detection (S/N=3) were in the range of 0.05-0.15 mg/kg. The recoveries were from 86.8% to 115.7%, and the relative standard deviations were between 0.73% and 5.61%. This method is rapid, convenient, accurate and reliable, and can be used for the rapid determination of the 13 UV absorbents in plastic food contact materials.
A rapid method based on ultra-performance convergence chromatography (UPC2) was developed for the analysis of 13 ultraviolet (UV) absorbents in plastic food contact materials. The UV absorbents were extracted from plastic food contact materials by supersonic extraction with methanol, purified by C18 solid phase extraction column, and analyzed via UPC2 before filtration with an organic filtration membrane (0.22 μm). An ACQUTY UPC2 HSS C18 SB chromatographic column (150 mm×3.0 mm, 1.8 μm) was used for the detection of the UV absorbents. An effective separation was achieved within 4 min under the optimized conditions. The mobile phases were supercritical carbon dioxide and isopropanol as a modifier. The results showed that the 13 UV absorbents exhibited good linear relationships in the respective linear ranges with the correlation coefficients no less than 0.9985. The limits of detection (S/N=3) were in the range of 0.05-0.15 mg/kg. The recoveries were from 86.8% to 115.7%, and the relative standard deviations were between 0.73% and 5.61%. This method is rapid, convenient, accurate and reliable, and can be used for the rapid determination of the 13 UV absorbents in plastic food contact materials.
2019, 37(9): 996-1003
doi: 10.3724/SP.J.1123.2019.03030
Abstract:
A method of gradient elution ion chromatography with integrated pulsed amperometric detection for simultaneous determination of twenty amino acids and six carbohydrates in soy sauce was established. The effects of column temperature, pH value of solution, and standing time were studied, and then the suitable gradient elution conditions were found for the determination. In the conditions that the flow rate is 0.25 mL/min, pH value of solution is in the range of 5.2-6.7, temperature of column is 35℃, the linear relationships of the 26 components are good and the correlation coefficients are not less than 0.995. Except glutamine, leucine, isoleucine and methionine, the limits of detection (S/N=3) of the other 22 components are less than 0.03 mg/L. The recoveries of the 26 components in soy sauce are 84.2%-109% at the spiked levels of 0.20, 0.50, 2.00 mg/L, and the relative standard deviations (RSDs) are in the range of 2.7%-7.8%. The method is efficient, easy, sensitive, and accurate for simultaneous determination of amino acids and carbohydrates in soy sauce, and can provide an effective research technique for adulterated soy sauce.
A method of gradient elution ion chromatography with integrated pulsed amperometric detection for simultaneous determination of twenty amino acids and six carbohydrates in soy sauce was established. The effects of column temperature, pH value of solution, and standing time were studied, and then the suitable gradient elution conditions were found for the determination. In the conditions that the flow rate is 0.25 mL/min, pH value of solution is in the range of 5.2-6.7, temperature of column is 35℃, the linear relationships of the 26 components are good and the correlation coefficients are not less than 0.995. Except glutamine, leucine, isoleucine and methionine, the limits of detection (S/N=3) of the other 22 components are less than 0.03 mg/L. The recoveries of the 26 components in soy sauce are 84.2%-109% at the spiked levels of 0.20, 0.50, 2.00 mg/L, and the relative standard deviations (RSDs) are in the range of 2.7%-7.8%. The method is efficient, easy, sensitive, and accurate for simultaneous determination of amino acids and carbohydrates in soy sauce, and can provide an effective research technique for adulterated soy sauce.
2019, 37(9): 1004-1010
doi: 10.3724/SP.J.1123.2019.03025
Abstract:
A chromatographic method was developed for the determination of glufosinate (GLUF), aminomethylphosphonic acid (AMPA), and glyphosate (GLY) in farmland soil by the post-column addition of alkali using high performance anion exchange chromatography-pulse amperometric detection. Samples were extracted with 2 mmol/L sodium hydroxide solution, then filtered through a 0.22 μm membrane, and purified by a IC-C18 column and IC-Na column. Three target compounds and coexisting ions in the filtered solution were separated on an IonPacAS11-HC anion exchange column (250 mm×4 mm), and were detected by the post-column addition of alkali using pulse amperometric detection. Results showed that GLUF and GLY had good linearity in the range of 20.0-1000 μg/L, and AMPA had good linearity in the range of 5.0-400 μg/L, with correlation coefficients above 0.999. The limits of detection of GLUF, AMPA, and GLY were 0.08, 0.02, and 0.04 mg/kg, respectively, and the recoveries were in the range of 80.2%-106% with RSDs of 0.7%-5.0% (n=6). The method provides strong anti-interference, high sensitivity, and accuracy, and can be adopted simply and quickly; therefore, it is suitable for detecting the residues of GLUF, AMPA, and GLY in farmland soil.
A chromatographic method was developed for the determination of glufosinate (GLUF), aminomethylphosphonic acid (AMPA), and glyphosate (GLY) in farmland soil by the post-column addition of alkali using high performance anion exchange chromatography-pulse amperometric detection. Samples were extracted with 2 mmol/L sodium hydroxide solution, then filtered through a 0.22 μm membrane, and purified by a IC-C18 column and IC-Na column. Three target compounds and coexisting ions in the filtered solution were separated on an IonPacAS11-HC anion exchange column (250 mm×4 mm), and were detected by the post-column addition of alkali using pulse amperometric detection. Results showed that GLUF and GLY had good linearity in the range of 20.0-1000 μg/L, and AMPA had good linearity in the range of 5.0-400 μg/L, with correlation coefficients above 0.999. The limits of detection of GLUF, AMPA, and GLY were 0.08, 0.02, and 0.04 mg/kg, respectively, and the recoveries were in the range of 80.2%-106% with RSDs of 0.7%-5.0% (n=6). The method provides strong anti-interference, high sensitivity, and accuracy, and can be adopted simply and quickly; therefore, it is suitable for detecting the residues of GLUF, AMPA, and GLY in farmland soil.
2019, 37(9): 1011-1018
doi: 10.3724/SP.J.1123.2019.01044
Abstract:
In this study, ultra performance liquid chromatography-quadrupole electrostatic field orbitrap mass spectrometry was used to establish a high-throughput screening method for 20 β -blockers and their metabolites in foods of animal origin. The sensitivity and applicability of the established method were improved by optimizing the instrument and pretreatment conditions. The samples were purified by high speed centrifugation at low temperature, and the compounds were separated by a C8 column. Qualitative and quantitative analyses of the compounds were performed in full MS/dd-MS2 (data-dependent MS2) mode. Twenty compounds showed a good linear relationship in the range 0.1-10 μg/L, with correlation coefficients (r2) greater than 0.99. The limits of detection (LODs) ranged from 1 to 5 μg/kg, while the limits of quantification (LOQs) ranged from 2 to 10 μg/kg. The average recoveries were 60.37%-100.84%, with relative standard deviations less than 10%. The method is operationally simple and has good reproducibility and high accuracy, which are essential for β -blockers and metabolite residue screening in foods of animal-origin.
In this study, ultra performance liquid chromatography-quadrupole electrostatic field orbitrap mass spectrometry was used to establish a high-throughput screening method for 20 β -blockers and their metabolites in foods of animal origin. The sensitivity and applicability of the established method were improved by optimizing the instrument and pretreatment conditions. The samples were purified by high speed centrifugation at low temperature, and the compounds were separated by a C8 column. Qualitative and quantitative analyses of the compounds were performed in full MS/dd-MS2 (data-dependent MS2) mode. Twenty compounds showed a good linear relationship in the range 0.1-10 μg/L, with correlation coefficients (r2) greater than 0.99. The limits of detection (LODs) ranged from 1 to 5 μg/kg, while the limits of quantification (LOQs) ranged from 2 to 10 μg/kg. The average recoveries were 60.37%-100.84%, with relative standard deviations less than 10%. The method is operationally simple and has good reproducibility and high accuracy, which are essential for β -blockers and metabolite residue screening in foods of animal-origin.
2019, 37(9): 1019-1025
doi: 10.3724/SP.J.1123.2019.02010
Abstract:
An analytical method for the determination of 34 pesticide residues in plant-derived foods was established using an automated QuEChERS sample preparation system combined with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample extraction and dispersive solid-phase extraction in the manual QuEChERS method were combined using the vortex vibration and centrifugation functions of the automated QuEChERS sample preparation system. The operating parameters and pretreatment steps were optimized, and the analytes were detected in the multiple reaction monitoring (MRM) mode. The quantification analysis was performed by the matrix-matched external standard method. The automated and the manual QuEChERS methods were compared from the methodological verification standpoint. The calibration curves showed good linearity in a certain range, and the correlation coefficients (R2) were greater than 0.99. The limits of detection and limits of quantification were 0.76-3.60 μg/kg and 2.28-10.80 μg/kg, respectively. Moreover, the recoveries ranged from 53.0% to 125.2%, and the relative standard deviations (RSDs) were less than 1.59% (n=5). The results obtained by the manual QuEChERS method were not significantly different from those obtained by the automated QuEChERS method. This method can effectively reduce the labor intensity and probability of error in the determination of pesticide residues.
An analytical method for the determination of 34 pesticide residues in plant-derived foods was established using an automated QuEChERS sample preparation system combined with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample extraction and dispersive solid-phase extraction in the manual QuEChERS method were combined using the vortex vibration and centrifugation functions of the automated QuEChERS sample preparation system. The operating parameters and pretreatment steps were optimized, and the analytes were detected in the multiple reaction monitoring (MRM) mode. The quantification analysis was performed by the matrix-matched external standard method. The automated and the manual QuEChERS methods were compared from the methodological verification standpoint. The calibration curves showed good linearity in a certain range, and the correlation coefficients (R2) were greater than 0.99. The limits of detection and limits of quantification were 0.76-3.60 μg/kg and 2.28-10.80 μg/kg, respectively. Moreover, the recoveries ranged from 53.0% to 125.2%, and the relative standard deviations (RSDs) were less than 1.59% (n=5). The results obtained by the manual QuEChERS method were not significantly different from those obtained by the automated QuEChERS method. This method can effectively reduce the labor intensity and probability of error in the determination of pesticide residues.
2019, 37(9): 1026-1033
doi: 10.3724/SP.J.1123.2019.01045
Abstract:
A chromatographic separation method for 27 fragrances in cosmetics and perfume raw materials was developed using gas chromatography-mass spectrometry (GC-MS). A weak polar capillary column and electron impact ion source were used in the GC-MS analysis, with methanol as the extraction solvent. The limits of detection were 1.2, 15, and 15 mg/kg for musk xylene, hydroxycitronellal, and hydroxyisohexyl-3-cyclohexene carboxaldehyde, respectively, and 3.0 mg/kg for the other 24 fragrances. The calibration line of the 27 fragrances presented a good relationship with correlation coefficients ≥ 0.996. At three spiked concentration levels, the relative standard deviations were <10% and the spiked recoveries were in the ranges of 73.3%-76.1% for musk xylene and 81.5%-118% for the other fragrances. Based on these determinations, one or more fragrance ingredients were detected in 69 perfume raw materials and cosmetics, the labels of which indicated that they contained fragrances. This method can be used to determine 27 fragrances in cosmetic and perfume raw materials.
A chromatographic separation method for 27 fragrances in cosmetics and perfume raw materials was developed using gas chromatography-mass spectrometry (GC-MS). A weak polar capillary column and electron impact ion source were used in the GC-MS analysis, with methanol as the extraction solvent. The limits of detection were 1.2, 15, and 15 mg/kg for musk xylene, hydroxycitronellal, and hydroxyisohexyl-3-cyclohexene carboxaldehyde, respectively, and 3.0 mg/kg for the other 24 fragrances. The calibration line of the 27 fragrances presented a good relationship with correlation coefficients ≥ 0.996. At three spiked concentration levels, the relative standard deviations were <10% and the spiked recoveries were in the ranges of 73.3%-76.1% for musk xylene and 81.5%-118% for the other fragrances. Based on these determinations, one or more fragrance ingredients were detected in 69 perfume raw materials and cosmetics, the labels of which indicated that they contained fragrances. This method can be used to determine 27 fragrances in cosmetic and perfume raw materials.
