Login In
2012 Volume 40 Issue 12
2012, 40(12): 1791-1796
doi: 10.3724/SP.J.1096.2012.20470
Abstract:
This paper presents two kinds of mercury-free electrochemical microsensors for simultaneous detection of heavy metals, which are L-aspartic acid/L-cysteine/gold nanoparticles (Asp/Cys/GNPs/microelectrode chip) and Sn film/gold nanoparticles modified microelectrode chip (Sn/GNPs/microelectrode chip). Electrochemical analysis of metal ions on Asp/Cys/GNPs/microelectrode chip was investigated by square wave voltammetry under the optimized conditions. The microsensor exhibited wide linear range from 5 μg/L to 2000 μg/L for Cu2+ and Pb2+ ions, with limit of detection of 1 μg/L. In situ tin film deposition was used in detection of heavy metals for the forming of alloy with heavy metals. Electrochemical analysis of metal ions on Sn/GNPs/microelectrode chip was investigated by square wave stripping voltammetry. The Sn/GNPs/microelectrode chip showed high sensitivity to Cu2+, Pb2+ and Zn2+ ions. This microsensor revealed good linear behavior in the examined concentration ranges from 5 to 500 μg/L for Cu2+ and Pb2+, from 10 to 500 μg/L for Zn2+, with a limit of detection of 2 μg/L for Cu2+, 3 μg/L for Pb2+ and 5 μg/L for Zn2+. In addition, metal ions detection method using the two kinds of microsensor are green, simple, reused and compatible with the microfluid chip for on-site analysis.
This paper presents two kinds of mercury-free electrochemical microsensors for simultaneous detection of heavy metals, which are L-aspartic acid/L-cysteine/gold nanoparticles (Asp/Cys/GNPs/microelectrode chip) and Sn film/gold nanoparticles modified microelectrode chip (Sn/GNPs/microelectrode chip). Electrochemical analysis of metal ions on Asp/Cys/GNPs/microelectrode chip was investigated by square wave voltammetry under the optimized conditions. The microsensor exhibited wide linear range from 5 μg/L to 2000 μg/L for Cu2+ and Pb2+ ions, with limit of detection of 1 μg/L. In situ tin film deposition was used in detection of heavy metals for the forming of alloy with heavy metals. Electrochemical analysis of metal ions on Sn/GNPs/microelectrode chip was investigated by square wave stripping voltammetry. The Sn/GNPs/microelectrode chip showed high sensitivity to Cu2+, Pb2+ and Zn2+ ions. This microsensor revealed good linear behavior in the examined concentration ranges from 5 to 500 μg/L for Cu2+ and Pb2+, from 10 to 500 μg/L for Zn2+, with a limit of detection of 2 μg/L for Cu2+, 3 μg/L for Pb2+ and 5 μg/L for Zn2+. In addition, metal ions detection method using the two kinds of microsensor are green, simple, reused and compatible with the microfluid chip for on-site analysis.
2012, 40(12): 1797-1802
doi: 10.3724/SP.J.1096.2012.20531
Abstract:
Atom transfer radical polymerization (ATRP) is a new class of signal amplification method. The polymer growth results in local accumulation of monomers to form long-chain polymers. The growth of long chain polymeric materials provides excess active groups for electroactive or photoactive molecules coupling, which in turn significantly increases the loading of signal molecules and enhanced detection sensitivity. This review introduced the mechanism of ATRP, summarized the recent application of ATRP in biosensing. Particularly, future study and prospect were envisioned.
Atom transfer radical polymerization (ATRP) is a new class of signal amplification method. The polymer growth results in local accumulation of monomers to form long-chain polymers. The growth of long chain polymeric materials provides excess active groups for electroactive or photoactive molecules coupling, which in turn significantly increases the loading of signal molecules and enhanced detection sensitivity. This review introduced the mechanism of ATRP, summarized the recent application of ATRP in biosensing. Particularly, future study and prospect were envisioned.
2012, 40(12): 1803-1806
doi: 10.3724/SP.J.1096.2012.20331
Abstract:
Polypeptide antibody pre-concentration method coupled with mass spectrometry detecting was established for the determination of serum polypeptide. Polypeptide was captured by agarose beads followed by binding of specific polyclonal antibodies from serum. After timed washing steps, the remaining bound polypeptides were eluted from the beads and detected by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). We optimized a protein A agarose bead-based platform amenable to high throughput peptide capture followed by mass spectrometry can achieve ion signal, with precision (RSD<12%) and accuracy (about 10% of relative error) sufficient for quantifying biomarkers in the physiologically relevant nmol/L range. The method for the detection of peptide 5 (pep5) in the clinical hepatocellular carcinoma serum had sensitivity of 78.0% and specificity of 90%. The method is appropriate for the detection of low concentration biomarkers in clinical samples, and it will be significant for earlier diagnosis of cancers.
Polypeptide antibody pre-concentration method coupled with mass spectrometry detecting was established for the determination of serum polypeptide. Polypeptide was captured by agarose beads followed by binding of specific polyclonal antibodies from serum. After timed washing steps, the remaining bound polypeptides were eluted from the beads and detected by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). We optimized a protein A agarose bead-based platform amenable to high throughput peptide capture followed by mass spectrometry can achieve ion signal, with precision (RSD<12%) and accuracy (about 10% of relative error) sufficient for quantifying biomarkers in the physiologically relevant nmol/L range. The method for the detection of peptide 5 (pep5) in the clinical hepatocellular carcinoma serum had sensitivity of 78.0% and specificity of 90%. The method is appropriate for the detection of low concentration biomarkers in clinical samples, and it will be significant for earlier diagnosis of cancers.
2012, 40(12): 1807-1815
doi: 10.3724/SP.J.1096.2012.20793
Abstract:
We have synthesized high-aspect-ratio gold nanorods (GNR) by using a three-step seed-mediated growth method. The aspect ratio of the GNRs is approximately 14. The modification of the GNRs was achieved by replacing the CTAB molecules on the surface of gold nanorods with the 11-mercaptoundecanoic (MUDA) molecules. The cytotoxicity of the as-prepared GNRs and their effects on endocytosis, adhesion, proliferation, intracellular reactive oxygen species (ROS) level and cytoskeleton of the cells were studied. Interestingly, by using the 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl-tetrazolium bromide (MTT) assay, the GNRs did not show a significant toxicity to HeLa cells. However, single cell viability assays showed that GNR uptake could influence the cell adhesion at the early stage, though the effect was not much, and the cell proliferation was promoted to some degree. Moreover, large amounts of GNR uptake will lead to increased intracellular ROS level and impaired the cell skeleton.
We have synthesized high-aspect-ratio gold nanorods (GNR) by using a three-step seed-mediated growth method. The aspect ratio of the GNRs is approximately 14. The modification of the GNRs was achieved by replacing the CTAB molecules on the surface of gold nanorods with the 11-mercaptoundecanoic (MUDA) molecules. The cytotoxicity of the as-prepared GNRs and their effects on endocytosis, adhesion, proliferation, intracellular reactive oxygen species (ROS) level and cytoskeleton of the cells were studied. Interestingly, by using the 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl-tetrazolium bromide (MTT) assay, the GNRs did not show a significant toxicity to HeLa cells. However, single cell viability assays showed that GNR uptake could influence the cell adhesion at the early stage, though the effect was not much, and the cell proliferation was promoted to some degree. Moreover, large amounts of GNR uptake will lead to increased intracellular ROS level and impaired the cell skeleton.
2012, 40(12): 1816-1821
doi: 10.3724/SP.J.1096.2012.20268
Abstract:
An indirect competitive chemiluminescence enzyme immonoassay (icCLEIA) for the quantitative analysis of furaltadone metabolite 5-morpholinomethyl-3-amino-2-oxazolidone (AMOZ) in shrimp sample was established with the highly sensitive luminol-H2O2-horseradish peroxidase(HRP)-4-iodophenol chemiluminescence reaction detection system. The icCLEIA method was based on a single-chain variable fragment (scFv) antibody against AMOZ derivative. The optimized assay conditions were 62.5 μg/L of coating antigen (5-morpholinomethyl-3-(glyoxalamino)-2-oxazolidone-ovalbumin, AMOZA-OVA), the dilute time of scFv antibody was 1:10, the immunoreaction time was 45 min, the dilute times and incubation time of HRP-goat anti mouse IgG were 1:10000 and 50 min, respectively. The icCLEIA results showed IC50 value, limit of detection (LOD) and linear range were 1.38 μg/L, 0.09 μg/L and 0.26-9.08 μg/L, respectively. Inter-assay and intra-assay RSD was both below 15%. The scFv antibody showed high specificity. The average recoveries of four spiked level of AMOZ were 72.3%, 73.4%, 72.6% and 78.6%, respectively. Compared with HPLC-MS/MS, there was a good correlation between the two methods (R2=0.9997). Thus, the established icCLEIA method could be further used for detecting AMOZ in aquatic products samples rapidly and efficiently.
An indirect competitive chemiluminescence enzyme immonoassay (icCLEIA) for the quantitative analysis of furaltadone metabolite 5-morpholinomethyl-3-amino-2-oxazolidone (AMOZ) in shrimp sample was established with the highly sensitive luminol-H2O2-horseradish peroxidase(HRP)-4-iodophenol chemiluminescence reaction detection system. The icCLEIA method was based on a single-chain variable fragment (scFv) antibody against AMOZ derivative. The optimized assay conditions were 62.5 μg/L of coating antigen (5-morpholinomethyl-3-(glyoxalamino)-2-oxazolidone-ovalbumin, AMOZA-OVA), the dilute time of scFv antibody was 1:10, the immunoreaction time was 45 min, the dilute times and incubation time of HRP-goat anti mouse IgG were 1:10000 and 50 min, respectively. The icCLEIA results showed IC50 value, limit of detection (LOD) and linear range were 1.38 μg/L, 0.09 μg/L and 0.26-9.08 μg/L, respectively. Inter-assay and intra-assay RSD was both below 15%. The scFv antibody showed high specificity. The average recoveries of four spiked level of AMOZ were 72.3%, 73.4%, 72.6% and 78.6%, respectively. Compared with HPLC-MS/MS, there was a good correlation between the two methods (R2=0.9997). Thus, the established icCLEIA method could be further used for detecting AMOZ in aquatic products samples rapidly and efficiently.
2012, 40(12): 1822-1826
doi: 10.3724/SP.J.1096.2012.20303
Abstract:
Layer-by-layer films of poly dimethyl diallyl ammonium chloride and DNA were assembled on the surface of a glassy carbon electrode to prepare DNA electrochemical sensor. The assembling of DNA was characterized by employing electrochemical methods and atomic force microscope. We used Ru(bpy)32+ as electrochemical catalyst to detect the oxidative damage of DNA in the membrane. The effects of incubation time and concentration of Fenton reagent on the damage of DNA were studied. The result showed that DNA could be damaged greatly when it was incubated in Fenton reagent for 15 min. The detectable concentration of Fenton reagent was 5.0×10-5 mol/L FeSO4/2.0×10-4 mol/L H2O2. The electrochemical method using Ru(bpy)32+ as catalyst possesses high-sensitivity for detecting the damage of DNA.
Layer-by-layer films of poly dimethyl diallyl ammonium chloride and DNA were assembled on the surface of a glassy carbon electrode to prepare DNA electrochemical sensor. The assembling of DNA was characterized by employing electrochemical methods and atomic force microscope. We used Ru(bpy)32+ as electrochemical catalyst to detect the oxidative damage of DNA in the membrane. The effects of incubation time and concentration of Fenton reagent on the damage of DNA were studied. The result showed that DNA could be damaged greatly when it was incubated in Fenton reagent for 15 min. The detectable concentration of Fenton reagent was 5.0×10-5 mol/L FeSO4/2.0×10-4 mol/L H2O2. The electrochemical method using Ru(bpy)32+ as catalyst possesses high-sensitivity for detecting the damage of DNA.
2012, 40(12): 1827-1831
doi: 10.3724/SP.J.1096.2012.20127
Abstract:
A RNA aptamer modified to DNA (N1) that could bind to the target of Ni2+ was found that could bind specifically to Hg2+ ion with typical secondary structure. Thereafter, several DNA aptamers with a certain conformation of sequence mutation and splice were designed in order to increase the property of Hg2+ binding, and Aptamer-based fluorescence assay for the Hg2+ ion determination was developed. The addition of the Hg2+ to a mixture containing the duplex of a fluorophore labeled aptamer and a quencher-modified antisense nucleic acid (Q2) would force the release of Q2 from labeled aptamer, which was spontaneously accompanied by the increase of fluorescence intensity and made Hg2+ in quantitative analysis. It was shown that stable labeled aptamer DNA and Q2 hydrogen bonds formed at concentration ration of 1:3(labeled aptamer and Q2, respectively), under the condition of 5 min denaturation in 94℃ and 30 min renaturation in room temperature (25℃) in the fluorescence assay preparation. For aptamer N1, the fluorescence assay results showed that linear response toward Hg2+ concentration with fluorescence quenching system ranged from 1.25 mg/L to 20 mg/L, with the limit of detection 0.625 mg/L. In order to improve the sensitivity of aptamer N1, 4 oligonucleotides (N4, N5, N6, N7) were designed and synthesized based on the structure of N1. The results showed that N5 had the best affinity and specificity to Hg2+ which displayed the linear range for the Hg2+ concentration detection was 0.156 mg/L to 2.5 mg/L with a detection limit of 78 μg/L.
A RNA aptamer modified to DNA (N1) that could bind to the target of Ni2+ was found that could bind specifically to Hg2+ ion with typical secondary structure. Thereafter, several DNA aptamers with a certain conformation of sequence mutation and splice were designed in order to increase the property of Hg2+ binding, and Aptamer-based fluorescence assay for the Hg2+ ion determination was developed. The addition of the Hg2+ to a mixture containing the duplex of a fluorophore labeled aptamer and a quencher-modified antisense nucleic acid (Q2) would force the release of Q2 from labeled aptamer, which was spontaneously accompanied by the increase of fluorescence intensity and made Hg2+ in quantitative analysis. It was shown that stable labeled aptamer DNA and Q2 hydrogen bonds formed at concentration ration of 1:3(labeled aptamer and Q2, respectively), under the condition of 5 min denaturation in 94℃ and 30 min renaturation in room temperature (25℃) in the fluorescence assay preparation. For aptamer N1, the fluorescence assay results showed that linear response toward Hg2+ concentration with fluorescence quenching system ranged from 1.25 mg/L to 20 mg/L, with the limit of detection 0.625 mg/L. In order to improve the sensitivity of aptamer N1, 4 oligonucleotides (N4, N5, N6, N7) were designed and synthesized based on the structure of N1. The results showed that N5 had the best affinity and specificity to Hg2+ which displayed the linear range for the Hg2+ concentration detection was 0.156 mg/L to 2.5 mg/L with a detection limit of 78 μg/L.
2012, 40(12): 1832-1838
doi: 10.3724/SP.J.1096.2012.20569
Abstract:
A novel organic metal framework compound-lithium 1,3,5-benzenetricarboxylic acid (Li-BTC) was polymerized on the bare glassy carbon electrode by electropolymerization method. Then, Nafion/GOx/MWNTs/poly-Li-BTC/GC electrode was fabricated by drop coating method. The morphology of the composite film containing MWNTs and poly-Li-BTC was characterized by scanning electron microscopy (SEM). The electrochemical performance of the modified electrode was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed the composite film increased the effective surface area and improved electrocatalytic activity of GC electrode. The electrochemical performance of Nafion/GOx/MWNTs/poly-Li-BTC/GC electrode for detection of glucose was investigated by cyclic voltammetry and chronoamperometry. The experiment results showed that the linear range for the detection of the glucose was from 0.02 to 1.56 mmol/L with a correlation coefficient of 0.9992, detection limit of 5.1 μmol/L (S/N=3:1). The Michaelis constant was 0.832 mmol/L and recovery rate was from 96.5% to 100.3% for the modified electrode. The prepared glucose biosensor has good repeatability, reproducibility, selectivity and stability, and can be applied to determine the glucose content in glucose injection samples.
A novel organic metal framework compound-lithium 1,3,5-benzenetricarboxylic acid (Li-BTC) was polymerized on the bare glassy carbon electrode by electropolymerization method. Then, Nafion/GOx/MWNTs/poly-Li-BTC/GC electrode was fabricated by drop coating method. The morphology of the composite film containing MWNTs and poly-Li-BTC was characterized by scanning electron microscopy (SEM). The electrochemical performance of the modified electrode was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed the composite film increased the effective surface area and improved electrocatalytic activity of GC electrode. The electrochemical performance of Nafion/GOx/MWNTs/poly-Li-BTC/GC electrode for detection of glucose was investigated by cyclic voltammetry and chronoamperometry. The experiment results showed that the linear range for the detection of the glucose was from 0.02 to 1.56 mmol/L with a correlation coefficient of 0.9992, detection limit of 5.1 μmol/L (S/N=3:1). The Michaelis constant was 0.832 mmol/L and recovery rate was from 96.5% to 100.3% for the modified electrode. The prepared glucose biosensor has good repeatability, reproducibility, selectivity and stability, and can be applied to determine the glucose content in glucose injection samples.
2012, 40(12): 1839-1844
doi: 10.3724/SP.J.1096.2012.20360
Abstract:
The agarose gel electrophoresis(AGE) is one of the low-cost, large scale technologies for the separation of metallic single-walled carbon nanotubes(m-SWCNTs) and semiconducting single-walled carbon nanotubes(s-SWCNTs). The separated m-SWCNTs are divided into several parts and characterized by the UV-visible-near infrared absorption spectrum and the Raman spectrum respectively. The results show that the moieties with the fastest electrophoresis migration rate contain more m-SWCNTs. Furthermore, the effects of different agarose concentrations on the separating efficiencies of SWCNTs are investigated. It is found that higher concentration of agarose gel is beneficial to the enrichment of the m-SWCNTs and the separating efficiency of the m-SWCNTs could be realized by increasing the charge density on the surface of the SWCNTs.
The agarose gel electrophoresis(AGE) is one of the low-cost, large scale technologies for the separation of metallic single-walled carbon nanotubes(m-SWCNTs) and semiconducting single-walled carbon nanotubes(s-SWCNTs). The separated m-SWCNTs are divided into several parts and characterized by the UV-visible-near infrared absorption spectrum and the Raman spectrum respectively. The results show that the moieties with the fastest electrophoresis migration rate contain more m-SWCNTs. Furthermore, the effects of different agarose concentrations on the separating efficiencies of SWCNTs are investigated. It is found that higher concentration of agarose gel is beneficial to the enrichment of the m-SWCNTs and the separating efficiency of the m-SWCNTs could be realized by increasing the charge density on the surface of the SWCNTs.
2012, 40(12): 1845-1851
doi: 10.3724/SP.J.1096.2012.20585
Abstract:
The detection of the expression of formate dehydrogenase (FDH) recombination proteins in E.coli by molecular methods is time-consuming and hard-working and needs to destruct E.coli cells. To explore a simple and rapid method without cell destruction to detect the real-time expression of FDH recombination proteins in E.coli, Laser Tweezers Raman spectroscopy (LTRS) was used to investigate the recombinant protein expression of formate dehydrogenase (FDH) in the single living E.coli cell at different culture times following the induction with isopropyl thiogalactoside (IPTG). The result showed that the characteristic peaks corresponding to the recombinant FDH protein were gradually enhanced with an in increase in IPTG induction time, indicating the expression and the accumulation of FDH protein in recombinant E.coli cells. This result is consistent with that obtained by the analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This evidence confirms that LTRS is an effectively method for detection of the real-time expression of FDH recombination proteins in the living single E.coli cell without cell destruction.
The detection of the expression of formate dehydrogenase (FDH) recombination proteins in E.coli by molecular methods is time-consuming and hard-working and needs to destruct E.coli cells. To explore a simple and rapid method without cell destruction to detect the real-time expression of FDH recombination proteins in E.coli, Laser Tweezers Raman spectroscopy (LTRS) was used to investigate the recombinant protein expression of formate dehydrogenase (FDH) in the single living E.coli cell at different culture times following the induction with isopropyl thiogalactoside (IPTG). The result showed that the characteristic peaks corresponding to the recombinant FDH protein were gradually enhanced with an in increase in IPTG induction time, indicating the expression and the accumulation of FDH protein in recombinant E.coli cells. This result is consistent with that obtained by the analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This evidence confirms that LTRS is an effectively method for detection of the real-time expression of FDH recombination proteins in the living single E.coli cell without cell destruction.
2012, 40(12): 1852-1858
doi: 10.3724/SP.J.1096.2012.20124
Abstract:
T-2 toxin and its 5 metabolites in rat plasma were simultaneously determined by an ultra performance liquid chromatography coupled with triple quadrupole-ion trap mass spectrometric (UPLC-QTRAP) method with high sensitivity. In the optimized solid phase extraction conditions, the rat plasma samples were purified and concentrated by a HLB column, and then the analytes were separated on a XDB-C18 column (4.6 mm×50 mm, 1.8 μm) with a mobile phase of methanol and aqueous solution containing 5 mmol/L ammonium acetate under a gradient elution. The mass spectrometric identification and quantification were performed with electrospray ionization in a positive by using multiple reaction monitoring mode with zearalanone as internal standard. In this established method, good linearities (R2>0.997) in the range from 0.1 to 500 μg/L with the limits of detection between 0.02 to 0.3 μg/L, and the recoveries varied from 93.5% to 120.3% with a relative standard deviations less than 13% were obtained. The method is rapid, reproducible, sensitive, and can be applied in the retrospective determination of the intoxication event of T-2 toxin.
T-2 toxin and its 5 metabolites in rat plasma were simultaneously determined by an ultra performance liquid chromatography coupled with triple quadrupole-ion trap mass spectrometric (UPLC-QTRAP) method with high sensitivity. In the optimized solid phase extraction conditions, the rat plasma samples were purified and concentrated by a HLB column, and then the analytes were separated on a XDB-C18 column (4.6 mm×50 mm, 1.8 μm) with a mobile phase of methanol and aqueous solution containing 5 mmol/L ammonium acetate under a gradient elution. The mass spectrometric identification and quantification were performed with electrospray ionization in a positive by using multiple reaction monitoring mode with zearalanone as internal standard. In this established method, good linearities (R2>0.997) in the range from 0.1 to 500 μg/L with the limits of detection between 0.02 to 0.3 μg/L, and the recoveries varied from 93.5% to 120.3% with a relative standard deviations less than 13% were obtained. The method is rapid, reproducible, sensitive, and can be applied in the retrospective determination of the intoxication event of T-2 toxin.
2012, 40(12): 1859-1864
doi: 10.3724/SP.J.1096.2012.20447
Abstract:
Carbonyl containing compounds can normally be determined by high performance liquid chromatography (HPLC) using pre-column derivatization with 2,4-dinitrophenylhydrazine (DNPH). Using this method, the steady-state kinetic parameters of 1-deoxy-D-xylulose-5-phosphate synthase (DXS) were measured. First, the enzymatic product 1-deoxy-D-xylulose-5-phosphate (DXP) was dephosphorylated by alkaline phosphatase, then the product 1-deoxy-D-xylulose (DX) was derived with DNPH in acidic solution to give the corresponding hydrazones which was subsequently determined by HPLC. The optimum derivatization conditions were as follows: acidity 1.5% perchloric acid, reaction temperature 37℃, reaction time of 60 min, molar ratio of DNPH to DXP 6:1. The HPLC was run with a linear gradient of methanol-water solvent system: 0 min, 40% methanol; 17 min, 80% methanol; 18 min, 40% methanol; 20 min, 40% methanol. The method has a detection limit of 1 mg/L for DXP and the linear correlation coefficient in the range of 0.005-1 g/L was 0.999. The relative standard deviation is less than 5.0%. The steady-state kinetic parameters of DXS determined with this method are identical with the reported data.
Carbonyl containing compounds can normally be determined by high performance liquid chromatography (HPLC) using pre-column derivatization with 2,4-dinitrophenylhydrazine (DNPH). Using this method, the steady-state kinetic parameters of 1-deoxy-D-xylulose-5-phosphate synthase (DXS) were measured. First, the enzymatic product 1-deoxy-D-xylulose-5-phosphate (DXP) was dephosphorylated by alkaline phosphatase, then the product 1-deoxy-D-xylulose (DX) was derived with DNPH in acidic solution to give the corresponding hydrazones which was subsequently determined by HPLC. The optimum derivatization conditions were as follows: acidity 1.5% perchloric acid, reaction temperature 37℃, reaction time of 60 min, molar ratio of DNPH to DXP 6:1. The HPLC was run with a linear gradient of methanol-water solvent system: 0 min, 40% methanol; 17 min, 80% methanol; 18 min, 40% methanol; 20 min, 40% methanol. The method has a detection limit of 1 mg/L for DXP and the linear correlation coefficient in the range of 0.005-1 g/L was 0.999. The relative standard deviation is less than 5.0%. The steady-state kinetic parameters of DXS determined with this method are identical with the reported data.
2012, 40(12): 1865-1870
doi: 10.3724/SP.J.1096.2012.20627
Abstract:
The BALB/c mice was exposed to deplete uranium (DU) solution (235U/238U=0.00431). Blood and the tissues of kidney, liver, spleen, cerebrum, femur, lung and testicle were collected in different time after the exposion. The uranium concentration and 235U/238U ratio in tissues were determined simultaneously by inductively coupled plasma mass spectrometry (ICP-MS), and to analyze the distribution and metabolism of DU in the body. The extracted and purified genomic DNA in kidney and liver was dialyzed to excluding the DU uncombined, and quantified by ultraviolet spectrophotometry. Then the DNA was diluted with special diluents, and the binding level of DU with genomic DNA in kidney and liver was detected by ICP-MS. Pt was confirmed as the internal standard to compensate matrix influence. The limits of detection in tissues were in the range of 0.0019 μg/kg to 0.0981 μg/kg. The precision (RSD) ranged from 0.9% to 2.1%, and the recovery was about 100%±10%. The results of 235U/238U isotopic ratio in the depleted uranium aerosols detected by ICP-MS were consistent with the results detected by α-spectrometer, and RSD=6%. The genomic DNA was diluted with neutral solution. The detection limit of uranium in DNA was 0.0016 μg/kg, and the recovery was 98.3%±7.3%. The analytical results showed that DU could be differentially accumulated in different tissues, and most of DU was accumulated in kidney and bone, and scarcely enter into the brain tissue. Especially, DU would be accumulated in bone for a long time. DU could combine with genomic DNA in kidney and liver, and the binding level of DU in kidney was relatively high and persistent. The uranium concentration in tissues had relationship to some extent with 235U/238U, and the 235U/238U isotopic ratio would be altered with uranium concentration. The uranium concentration and 235U/238U can be sensitive indicator to measure the pollution of uranium.
The BALB/c mice was exposed to deplete uranium (DU) solution (235U/238U=0.00431). Blood and the tissues of kidney, liver, spleen, cerebrum, femur, lung and testicle were collected in different time after the exposion. The uranium concentration and 235U/238U ratio in tissues were determined simultaneously by inductively coupled plasma mass spectrometry (ICP-MS), and to analyze the distribution and metabolism of DU in the body. The extracted and purified genomic DNA in kidney and liver was dialyzed to excluding the DU uncombined, and quantified by ultraviolet spectrophotometry. Then the DNA was diluted with special diluents, and the binding level of DU with genomic DNA in kidney and liver was detected by ICP-MS. Pt was confirmed as the internal standard to compensate matrix influence. The limits of detection in tissues were in the range of 0.0019 μg/kg to 0.0981 μg/kg. The precision (RSD) ranged from 0.9% to 2.1%, and the recovery was about 100%±10%. The results of 235U/238U isotopic ratio in the depleted uranium aerosols detected by ICP-MS were consistent with the results detected by α-spectrometer, and RSD=6%. The genomic DNA was diluted with neutral solution. The detection limit of uranium in DNA was 0.0016 μg/kg, and the recovery was 98.3%±7.3%. The analytical results showed that DU could be differentially accumulated in different tissues, and most of DU was accumulated in kidney and bone, and scarcely enter into the brain tissue. Especially, DU would be accumulated in bone for a long time. DU could combine with genomic DNA in kidney and liver, and the binding level of DU in kidney was relatively high and persistent. The uranium concentration in tissues had relationship to some extent with 235U/238U, and the 235U/238U isotopic ratio would be altered with uranium concentration. The uranium concentration and 235U/238U can be sensitive indicator to measure the pollution of uranium.
2012, 40(12): 1871-1876
doi: 10.3724/SP.J.1096.2012.20161
Abstract:
A method was developed for monitoring five sulfonamides (SAs) in feeds by using molecularly imprinted polymers (MIPs) as selective solid-phase extraction sorbents coupled with high performance liquid chromatography. The MIPs were firstly synthesized by ultraviolet initiated using sulfadiazine as template. Then, the molecularly printed solid phase extraction (MISPE) column was prepared, and the MIPs were used as adsorbent. Meanwhile, the procedures of loading, washing and eluting conditions were optimized. Under the optimum conditions, the detection limit range of five SAs was 0.14-0.23 mg/kg and the quantification limit range was 0.38-0.47 mg/kg. The average recoveries were in the range of 72.1%-89.3% with a batch and batch sampling relative standard deviations less than 7.9% and 9.2%, respectively. It showed that the MISPE column decreased the matrix effect and had a better selectivity and a lower limit of quantification than Alumina B column.
A method was developed for monitoring five sulfonamides (SAs) in feeds by using molecularly imprinted polymers (MIPs) as selective solid-phase extraction sorbents coupled with high performance liquid chromatography. The MIPs were firstly synthesized by ultraviolet initiated using sulfadiazine as template. Then, the molecularly printed solid phase extraction (MISPE) column was prepared, and the MIPs were used as adsorbent. Meanwhile, the procedures of loading, washing and eluting conditions were optimized. Under the optimum conditions, the detection limit range of five SAs was 0.14-0.23 mg/kg and the quantification limit range was 0.38-0.47 mg/kg. The average recoveries were in the range of 72.1%-89.3% with a batch and batch sampling relative standard deviations less than 7.9% and 9.2%, respectively. It showed that the MISPE column decreased the matrix effect and had a better selectivity and a lower limit of quantification than Alumina B column.
2012, 40(12): 1877-1882
doi: 10.3724/SP.J.1096.2012.11429
Abstract:
A graphene-L-cystine modified glassy carbon electrode (GR-L-CysS/GCE) has been prepared. The electrochemical behavior of isoprenaline hydrochloride at the modified electrode has been studied. In 0.2 mol/L Na2HPO4-citric acid (pH 7.4) buffer, GR-L-CysS/GCE exhibited excellent catalytic and enhancement effect on the electrochemical oxidation of isoprenaline hydrochloride, and the oxidation peak current increased ca.13 times compared with that at bare GCE. The measurement parameters were optimized. Under the optimal conditions, isoprenaline hydrochloride concentration was linear with peak current in the range of 4.0×10-6-1.6×10-4 mol/L (R=0.9977), and the detection limit was 8.4×10-7 mol/L(S/N=3). The mechanism investigation showed that the reaction of isoprenaline hydrochloride at the modified electrode was a process with one-proton and one-electron transfer, and the coefficient of electron transfer α is 0.4635. This method was successfully used in the determination of isoprenaline hydrochloride in injection with the recovery between 94.9%-102.9%.
A graphene-L-cystine modified glassy carbon electrode (GR-L-CysS/GCE) has been prepared. The electrochemical behavior of isoprenaline hydrochloride at the modified electrode has been studied. In 0.2 mol/L Na2HPO4-citric acid (pH 7.4) buffer, GR-L-CysS/GCE exhibited excellent catalytic and enhancement effect on the electrochemical oxidation of isoprenaline hydrochloride, and the oxidation peak current increased ca.13 times compared with that at bare GCE. The measurement parameters were optimized. Under the optimal conditions, isoprenaline hydrochloride concentration was linear with peak current in the range of 4.0×10-6-1.6×10-4 mol/L (R=0.9977), and the detection limit was 8.4×10-7 mol/L(S/N=3). The mechanism investigation showed that the reaction of isoprenaline hydrochloride at the modified electrode was a process with one-proton and one-electron transfer, and the coefficient of electron transfer α is 0.4635. This method was successfully used in the determination of isoprenaline hydrochloride in injection with the recovery between 94.9%-102.9%.
2012, 40(12): 1883-1889
doi: 10.3724/SP.J.1096.2012.20542
Abstract:
A new method was developed for the on-line analysis of flavor compounds in toothpastes without any sample preparation by direct injection time-of-flight mass spectrometry with single photon ionization (SPI-TOFMS). The samples were directly taken into the ionization source by the quartz capillary tube and the pressure condition of the ionization source was optimized. Under the discrimination of characteristic mass spectra of flavor compounds, rapid and accurate identification of flavors in toothpastes was achieved. The analysis time for a single sample was only 0.5 min. This method was applied to on-line and in-situ monitoring of flavor compounds during tooth brushing process. The influence of water content on release of flavor compounds from toothpastes was studied. The results indicate that direct injection SPI-TOFMS can monitor the composition and concentration of flavor compounds in real time. The method could be suitable to analyze the flavors from various samples such as food and cosmetics.
A new method was developed for the on-line analysis of flavor compounds in toothpastes without any sample preparation by direct injection time-of-flight mass spectrometry with single photon ionization (SPI-TOFMS). The samples were directly taken into the ionization source by the quartz capillary tube and the pressure condition of the ionization source was optimized. Under the discrimination of characteristic mass spectra of flavor compounds, rapid and accurate identification of flavors in toothpastes was achieved. The analysis time for a single sample was only 0.5 min. This method was applied to on-line and in-situ monitoring of flavor compounds during tooth brushing process. The influence of water content on release of flavor compounds from toothpastes was studied. The results indicate that direct injection SPI-TOFMS can monitor the composition and concentration of flavor compounds in real time. The method could be suitable to analyze the flavors from various samples such as food and cosmetics.
2012, 40(12): 1890-1896
doi: 10.3724/SP.J.1096.2012.20408
Abstract:
Monoclinic fusiform zirconium dioxide (ZrO2) nanoparticles were synthesized by hydrothermal method, a method for the determination of Nickel2+ was developed by inductively coupled plasma mass spectrometry(ICP-MS) with monoclinic fusiform nanometer-sized ZrO2 as absorbent. The detection limit to Ni2+ was 0.029 μg/L and the relative standard deviation was 2.7% (n=6). Optimal adsorption and elution conditions of nanometer-sized ZrO2 to Ni2+ were studied, adsorption percentage of nanometer-sized ZrO2 to Ni2+ was more than 99% under pH 9.0 and 10 min, 2 mL 0.5 mol/L HCl was sufficient for elution to Ni2+ more than 98%. The static adsorption capacity of ZrO2 to Ni2+ was 198.4 μg/g and enrichment factor reached 250. Effects of co-existing ions and regeneration properties were discussed. The method has been applied to the determination of trace Ni2+ in real water samples, the recoveries were 96.3%-101.4%.
Monoclinic fusiform zirconium dioxide (ZrO2) nanoparticles were synthesized by hydrothermal method, a method for the determination of Nickel2+ was developed by inductively coupled plasma mass spectrometry(ICP-MS) with monoclinic fusiform nanometer-sized ZrO2 as absorbent. The detection limit to Ni2+ was 0.029 μg/L and the relative standard deviation was 2.7% (n=6). Optimal adsorption and elution conditions of nanometer-sized ZrO2 to Ni2+ were studied, adsorption percentage of nanometer-sized ZrO2 to Ni2+ was more than 99% under pH 9.0 and 10 min, 2 mL 0.5 mol/L HCl was sufficient for elution to Ni2+ more than 98%. The static adsorption capacity of ZrO2 to Ni2+ was 198.4 μg/g and enrichment factor reached 250. Effects of co-existing ions and regeneration properties were discussed. The method has been applied to the determination of trace Ni2+ in real water samples, the recoveries were 96.3%-101.4%.
2012, 40(12): 1897-1901
doi: 10.3724/SP.J.1096.2012.20497
Abstract:
Determination of the δ18O value of diatom can obtain the initial information of its oxygen isotopic composition, and also has favorable application prospects in paleoenvironment, paleontology, petroleum exploration and environmental prediction. We carried out eight-step fluorination experiments with BrF5 reagent on diatom samples and quartz standard to reveal variation of oxygen isotopic composition in different steps. The eight-step fluorination determined the proportion of surface oxygen to be 25%-28%. The δ18O values obtained from the above processes were all around (35.34±0.15)‰. Then we simplified the eight-step fluorination to two-step fluorination. First, we removed the surface oxygen of specific sedimentary diatoms, and then totally fluoridated the samples. The difference of δ18O values from eight-step and two-step fluorination experiments on the same samples was only 0.3‰. The accuracy of measurement has reached or preceded the repeated measurement error of ±0.5‰ in the international studies. On the basis of many conditional experiments, the stepwise fluorination methods on the diatoms were established. For diatom samples with weight of a mg, the 0.392 aK mL (K=0.18) BrF5 were loaded in the first step, and heated to 550℃ for 1 h; and then five times of theoretical quantity of BrF5 were loaded in the second step after the system regain vacuum, and heated to 550℃ for 3 h. The released oxygen were converted to CO2, and then analysed by MAT-252 to obtain δ18O value of diatom samples.
Determination of the δ18O value of diatom can obtain the initial information of its oxygen isotopic composition, and also has favorable application prospects in paleoenvironment, paleontology, petroleum exploration and environmental prediction. We carried out eight-step fluorination experiments with BrF5 reagent on diatom samples and quartz standard to reveal variation of oxygen isotopic composition in different steps. The eight-step fluorination determined the proportion of surface oxygen to be 25%-28%. The δ18O values obtained from the above processes were all around (35.34±0.15)‰. Then we simplified the eight-step fluorination to two-step fluorination. First, we removed the surface oxygen of specific sedimentary diatoms, and then totally fluoridated the samples. The difference of δ18O values from eight-step and two-step fluorination experiments on the same samples was only 0.3‰. The accuracy of measurement has reached or preceded the repeated measurement error of ±0.5‰ in the international studies. On the basis of many conditional experiments, the stepwise fluorination methods on the diatoms were established. For diatom samples with weight of a mg, the 0.392 aK mL (K=0.18) BrF5 were loaded in the first step, and heated to 550℃ for 1 h; and then five times of theoretical quantity of BrF5 were loaded in the second step after the system regain vacuum, and heated to 550℃ for 3 h. The released oxygen were converted to CO2, and then analysed by MAT-252 to obtain δ18O value of diatom samples.
2012, 40(12): 1902-1906
doi: 10.3724/SP.J.1096.2012.20610
Abstract:
A method for the simultaneous determination of four steradienes in vegetable oils by high performance liquid chromatography (HPLC) was established. The sample was dissolved in petroleum ether and passed through a silica gel column, and the analytes were eluted with petroleum ether. The chromatographic separation was carried out on a C30 column (250 mm×4.6 mm i.d, 5 μm) using UV detection at 235 nm. Acetonitrile/tert-butyl methyl ether (75:25, V/V) was served as mobile phase in isocratic elution. Results showed good linear ranges for 4 steradienes from 0.025 mg/L to 1.0 mg/L with correlation coefficients(r2)>0.999. The mean recoveries were in the range of 89.2%-109.8% at three spiked levels of 0.050, 0.10 and 0.50 mg/kg, and the relative standard deviations (RSDs) were less than 8%. The limits of detection (LODs) were of 0.010 mg/kg. The proposed method had been applied in real sample analysis.
A method for the simultaneous determination of four steradienes in vegetable oils by high performance liquid chromatography (HPLC) was established. The sample was dissolved in petroleum ether and passed through a silica gel column, and the analytes were eluted with petroleum ether. The chromatographic separation was carried out on a C30 column (250 mm×4.6 mm i.d, 5 μm) using UV detection at 235 nm. Acetonitrile/tert-butyl methyl ether (75:25, V/V) was served as mobile phase in isocratic elution. Results showed good linear ranges for 4 steradienes from 0.025 mg/L to 1.0 mg/L with correlation coefficients(r2)>0.999. The mean recoveries were in the range of 89.2%-109.8% at three spiked levels of 0.050, 0.10 and 0.50 mg/kg, and the relative standard deviations (RSDs) were less than 8%. The limits of detection (LODs) were of 0.010 mg/kg. The proposed method had been applied in real sample analysis.
2012, 40(12): 1907-1912
doi: 10.3724/SP.J.1096.2012.20255
Abstract:
Based on the differential chemiluminescent rate of amikacin (AMK) and hydrochlorothiazide (HCT) in the system of Luminol-peroxymonosulfate (PMS), a novel time-resolved post-chemiluminescence method was established for the simultaneous determination of AMK and HCT. The HCT system gives the highest chemiluminescence intensity at 1 s, whereas the AMK system gives its most intense chemiluminescence emission at 39.7 s. The kinetic curve showed two separate chemiluminescence peaks at different time without disturbing each other. Under the optimum conditions described above, the analytical performance was obtained. The linear response for the determination of HCT and AMK was in the range from 8.0×10-5 to 4.0×10-3 g/L and from 8.0×10-4 to 4.0×10-2 g/L. The relative standard diviation of AMK (4.0×10-3 g/L) and HCT (4.0×10-4 g/L) are 3.7% and 2.4% (n=11), and the detection limit (3) of AMK and HCT are 2.0×10-4 g/L and 2.0×10-5 g/L, respectively.
Based on the differential chemiluminescent rate of amikacin (AMK) and hydrochlorothiazide (HCT) in the system of Luminol-peroxymonosulfate (PMS), a novel time-resolved post-chemiluminescence method was established for the simultaneous determination of AMK and HCT. The HCT system gives the highest chemiluminescence intensity at 1 s, whereas the AMK system gives its most intense chemiluminescence emission at 39.7 s. The kinetic curve showed two separate chemiluminescence peaks at different time without disturbing each other. Under the optimum conditions described above, the analytical performance was obtained. The linear response for the determination of HCT and AMK was in the range from 8.0×10-5 to 4.0×10-3 g/L and from 8.0×10-4 to 4.0×10-2 g/L. The relative standard diviation of AMK (4.0×10-3 g/L) and HCT (4.0×10-4 g/L) are 3.7% and 2.4% (n=11), and the detection limit (3) of AMK and HCT are 2.0×10-4 g/L and 2.0×10-5 g/L, respectively.
2012, 40(12): 1913-1918
doi: 10.3724/SP.J.1096.2012.20495
Abstract:
The terahertz (THz) spectra of chlorothalonil have been investigated from experimental spectrum and theoretical simulation in range of 0.4-3.0 THz. Based on terahertz time-domain spectroscopy (THz-TDS), the absorption and refraction spectra of chlorothalonil were obtained. To analyze the experimental spectrum, making up for the deficiency of isolated-molecule analysis, the structural changes and vibrational absorption spectrum of chlorothalonil were calculated in solid-state form, then analyze the source of absorption peaks. The results clearly demonstrate that the solid-state theory simulation is in good agreement with experiment where isolated-molecule simulation is not able to reproduce the spectral features, and the solid-state theory simulation complete the assignment of eleven absorption peaks. The observed spectral features of chlorothalonil molecule mainly originate from intra-molecular interactions of Cl—C—C, N—C—C and crystal packing vibrations in crystalline unit cell.
The terahertz (THz) spectra of chlorothalonil have been investigated from experimental spectrum and theoretical simulation in range of 0.4-3.0 THz. Based on terahertz time-domain spectroscopy (THz-TDS), the absorption and refraction spectra of chlorothalonil were obtained. To analyze the experimental spectrum, making up for the deficiency of isolated-molecule analysis, the structural changes and vibrational absorption spectrum of chlorothalonil were calculated in solid-state form, then analyze the source of absorption peaks. The results clearly demonstrate that the solid-state theory simulation is in good agreement with experiment where isolated-molecule simulation is not able to reproduce the spectral features, and the solid-state theory simulation complete the assignment of eleven absorption peaks. The observed spectral features of chlorothalonil molecule mainly originate from intra-molecular interactions of Cl—C—C, N—C—C and crystal packing vibrations in crystalline unit cell.
2012, 40(12): 1919-1923
doi: 10.3724/SP.J.1096.2012.20428
Abstract:
A new rapid analytical method based on direct solvent extraction (DSE)/gas chromatography-mass spectrometry (GC-MS) was developed to analyze 2-dodecyclobutanone (2-DCB) to detect γ-ray irradiated beef. A 5 g sample of ground beef patties was homogenized with 7 g of anhydrous sodium sulfate and blended with 150 mL acetonitrile using a blender for 2 min. The extract solvent was carefully transferred to a 500 mL round-bottom flask through filter paper. And the procedure repeated for two times. Then, the extraction solutions were evaporated to dryness using a rotary evaporator. The round-bottom flask was washed with hexane, and the solution was collected into a 50 mL volumetric flask. The 10 mL hexane aliquot was dried to 1 mL via nitrogen stream and then purified with a silica cartridge (1 g, 6 mL). The elution was concentrated to 1 mL with a nitrogen stream, and 1 μL was injected into the gas chromatography-mass spectrometer. The limit of detection and quantitation was 0.004 and 0.01 mg/kg, respectively. The procedure was evaluated with a recovery test in six samples spiked with 2-DCB at 0.01 and 0.5mg/kg of ground beef, resulting in 87.9%-91.6% recoveries with mostly less than 7% RSD. The operation time for sample preparation was about 60 to 90 min. The method was used to detect 2-DCB in ground beef irradiated at 5 targeted absorbed doses of 0.5, 1.0, 3.0, 5.0 and 7.0 kGy and the concentration of 2-DCB increased linearly with dose (y=0.0608x-0.0004, R2=0.9899).
A new rapid analytical method based on direct solvent extraction (DSE)/gas chromatography-mass spectrometry (GC-MS) was developed to analyze 2-dodecyclobutanone (2-DCB) to detect γ-ray irradiated beef. A 5 g sample of ground beef patties was homogenized with 7 g of anhydrous sodium sulfate and blended with 150 mL acetonitrile using a blender for 2 min. The extract solvent was carefully transferred to a 500 mL round-bottom flask through filter paper. And the procedure repeated for two times. Then, the extraction solutions were evaporated to dryness using a rotary evaporator. The round-bottom flask was washed with hexane, and the solution was collected into a 50 mL volumetric flask. The 10 mL hexane aliquot was dried to 1 mL via nitrogen stream and then purified with a silica cartridge (1 g, 6 mL). The elution was concentrated to 1 mL with a nitrogen stream, and 1 μL was injected into the gas chromatography-mass spectrometer. The limit of detection and quantitation was 0.004 and 0.01 mg/kg, respectively. The procedure was evaluated with a recovery test in six samples spiked with 2-DCB at 0.01 and 0.5mg/kg of ground beef, resulting in 87.9%-91.6% recoveries with mostly less than 7% RSD. The operation time for sample preparation was about 60 to 90 min. The method was used to detect 2-DCB in ground beef irradiated at 5 targeted absorbed doses of 0.5, 1.0, 3.0, 5.0 and 7.0 kGy and the concentration of 2-DCB increased linearly with dose (y=0.0608x-0.0004, R2=0.9899).
2012, 40(12): 1924-1928
doi: 10.3724/SP.J.1096.2012.20371
Abstract:
A method for the determination of chlormequat (CQ) in muscles of mice using solid phase extraction with liquid chromatography tandem mass spectrometry was developed. CQ was extracted using acetonitrile, cleaned-up by Weak Cation-exchange (WCX) solid phase extraction (SPE) cartridges and then eluted by 3 mL of formic acid-methanol (1:99, V/V) by gravity. The separation was performed on a hydrophilic interaction liquid chromatography (HILIC) column with aqueous solution containing 10 mmol/L ammonium acetate and 0.1% formic acid-acetonitrile (40:60, V/V) as the mobile phase. CQ was determined in the mode of electrospray ionization source (ESI+) and multiple-reaction monitoring (MRM). The quantification was carried out by matrix-matched external standard curve. The results showed that the calibration curve was linear in the range of 5.0-500.0 μg/L with the correlation coefficient of 0.9991. The mean recovery of CQ in spiked muscle samples was 73.2%-82.3% and the relative standard deviation (RSD) was less than 9.3% at 10.0, 100.0 and 200.0 μg/kg with three spiked levels (n=7). The limit of quantification (LOQ) for CQ was 10.0 μg/kg. The method was successfully applied to the analysis of trace level of CQ in muscles of mice.
A method for the determination of chlormequat (CQ) in muscles of mice using solid phase extraction with liquid chromatography tandem mass spectrometry was developed. CQ was extracted using acetonitrile, cleaned-up by Weak Cation-exchange (WCX) solid phase extraction (SPE) cartridges and then eluted by 3 mL of formic acid-methanol (1:99, V/V) by gravity. The separation was performed on a hydrophilic interaction liquid chromatography (HILIC) column with aqueous solution containing 10 mmol/L ammonium acetate and 0.1% formic acid-acetonitrile (40:60, V/V) as the mobile phase. CQ was determined in the mode of electrospray ionization source (ESI+) and multiple-reaction monitoring (MRM). The quantification was carried out by matrix-matched external standard curve. The results showed that the calibration curve was linear in the range of 5.0-500.0 μg/L with the correlation coefficient of 0.9991. The mean recovery of CQ in spiked muscle samples was 73.2%-82.3% and the relative standard deviation (RSD) was less than 9.3% at 10.0, 100.0 and 200.0 μg/kg with three spiked levels (n=7). The limit of quantification (LOQ) for CQ was 10.0 μg/kg. The method was successfully applied to the analysis of trace level of CQ in muscles of mice.
2012, 40(12): 1929-1932
doi: 10.3724/SP.J.1096.2012.20399
Abstract:
Lewis bases with lone-pair electrons were found to enhance the efficiency of chemical vapor generation (CVG) of gold with NaBH4 as the reductant. Such effect was tested by using ether, tetrahydrofuran, and triethylamine as the Lewis bases and a nondispersive atomic fluorescence spectrometer as detector. The results showed that the Lewis bases and DDTC gave similar enhancement effect for the CVG of gold. The detection limit and precision were found to be 1 μg/L and 8% (RSD), respectively. The results showed that Lewis bases with lone-pair electrons played an important role in the enhancement of the CVG efficiency of gold.
Lewis bases with lone-pair electrons were found to enhance the efficiency of chemical vapor generation (CVG) of gold with NaBH4 as the reductant. Such effect was tested by using ether, tetrahydrofuran, and triethylamine as the Lewis bases and a nondispersive atomic fluorescence spectrometer as detector. The results showed that the Lewis bases and DDTC gave similar enhancement effect for the CVG of gold. The detection limit and precision were found to be 1 μg/L and 8% (RSD), respectively. The results showed that Lewis bases with lone-pair electrons played an important role in the enhancement of the CVG efficiency of gold.
2012, 40(12): 1933-1937
doi: 10.3724/SP.J.1096.2012.10542
Abstract:
In this review, we aim to introduce a relatively new approach, metabolomics, and explore its potential for cancer diagnosis. We will briefly introduce the concept of metabolomics and its relationship with other omics studies in systems biology for cancer detection. The field of metabolomics focuses on the parallel measurement of hundreds of small molecule metabolites in biological samples such as blood, urine, and biopsied tissue. Since metabolite levels are sensitive to subtle changes in the pathological status, metabolomics promises novel avenues for early cancer detection and a better understanding of cancer processes. In fact, many previous metabolomics studies have clearly demons-trated the promises of metabolomics not only for the diagnosis of various kinds of cancer, but also for therapeutic monitoring as well as for drug development. In addition, in this review we will discuss the challenges and future directions for developing metabolomics methods towards clinical applications for cancer diagnosis.
In this review, we aim to introduce a relatively new approach, metabolomics, and explore its potential for cancer diagnosis. We will briefly introduce the concept of metabolomics and its relationship with other omics studies in systems biology for cancer detection. The field of metabolomics focuses on the parallel measurement of hundreds of small molecule metabolites in biological samples such as blood, urine, and biopsied tissue. Since metabolite levels are sensitive to subtle changes in the pathological status, metabolomics promises novel avenues for early cancer detection and a better understanding of cancer processes. In fact, many previous metabolomics studies have clearly demons-trated the promises of metabolomics not only for the diagnosis of various kinds of cancer, but also for therapeutic monitoring as well as for drug development. In addition, in this review we will discuss the challenges and future directions for developing metabolomics methods towards clinical applications for cancer diagnosis.
2012, 40(12): 1938-1944
doi: 10.3724/SP.J.1096.2012.20999
Abstract:
Nanomaterials have been increasingly used recently as the leading recognition elements in the biosensing area. The unique properties of functional nanomaterials have enhanced the detection behaviors of biosenors to a rather high level. This comment focuses on all papers published in all Chinese Journals in 2011 on the fabrication of various biosensors based on the functional nanomaterials. Materials with different structures used to construct the biosensors are classified and reviewed in details, followed by a discussion of their applications in life sciences. The prospect of the biosensors in China is also discussed briefly and compared with the research trend in the word.
Nanomaterials have been increasingly used recently as the leading recognition elements in the biosensing area. The unique properties of functional nanomaterials have enhanced the detection behaviors of biosenors to a rather high level. This comment focuses on all papers published in all Chinese Journals in 2011 on the fabrication of various biosensors based on the functional nanomaterials. Materials with different structures used to construct the biosensors are classified and reviewed in details, followed by a discussion of their applications in life sciences. The prospect of the biosensors in China is also discussed briefly and compared with the research trend in the word.
2012, 40(12): 1945-1949
doi: 10.3724/SP.J.1096.2012.20352
Abstract:
Due to the high temperature steam sterilization in the fermentation process, traditional "enzyme membrane" glucose biosensors are no longer suitable for online glucose detection. This leads to failure of real-time glucose feeding control, consequently affecting the quality and yields of fermentation. In order to solve this problem, a glucose on-line detection system for monitoring the fermentation process was set up. The problem was solved by using a self-developed "enzyme solution" glucose biosensor which stands high temperature. Another difficult problem about on-line sampling was solved by using a self-developed dialysis sampling system which also stands high temperature. Experimental results show that the sensitivity of the sensor is 0.259 nA/(mg/L), the detection limit is 0.7 mg/L and the RSD is 2.0% at the glucose concentration of 500 mg/L, and that the system responds linearly to the glucose concentration in the range of 0-1000 mg/L. These results were compared with those on a commercial off-line SBA-40E Biosensing analyzer, exhibiting an excellent linear correlation with the linear coefficient close to 1. Glucose concentration was measured on-line in the coli fermentation process with the detection system, and the results exhibit the same variation trend to the commercial off-line SBA-40E Biosensing Analyzer.
Due to the high temperature steam sterilization in the fermentation process, traditional "enzyme membrane" glucose biosensors are no longer suitable for online glucose detection. This leads to failure of real-time glucose feeding control, consequently affecting the quality and yields of fermentation. In order to solve this problem, a glucose on-line detection system for monitoring the fermentation process was set up. The problem was solved by using a self-developed "enzyme solution" glucose biosensor which stands high temperature. Another difficult problem about on-line sampling was solved by using a self-developed dialysis sampling system which also stands high temperature. Experimental results show that the sensitivity of the sensor is 0.259 nA/(mg/L), the detection limit is 0.7 mg/L and the RSD is 2.0% at the glucose concentration of 500 mg/L, and that the system responds linearly to the glucose concentration in the range of 0-1000 mg/L. These results were compared with those on a commercial off-line SBA-40E Biosensing analyzer, exhibiting an excellent linear correlation with the linear coefficient close to 1. Glucose concentration was measured on-line in the coli fermentation process with the detection system, and the results exhibit the same variation trend to the commercial off-line SBA-40E Biosensing Analyzer.
2012, 40(12): 1950-1951
doi: 10.3724/SP.J.1096.2012.20890
Abstract:
A temperature programed digestion-atomic absorption spectrometry method was established for the determination of lead, cadmiun, nickel, and chromiun in soil. The temperature program for digestion was set as 80℃ for 1 h, 120℃ for 2 h, and 300℃ for the remove of acid solution. The result shows that the average recoveries for lead, cadmiun, nickel, and chromiun were 100.4%, 99.4%, 95.0%, and 94.0%, respectively. Verified by the standard samples GBW07406 and GBW07407, the established method was found to have a good accuracy. In compariaon with the traditional digestion method, the established method in this atudy was proved to have better accuracy and precision. This method was also proved to have good operability and it's easy to spread.
A temperature programed digestion-atomic absorption spectrometry method was established for the determination of lead, cadmiun, nickel, and chromiun in soil. The temperature program for digestion was set as 80℃ for 1 h, 120℃ for 2 h, and 300℃ for the remove of acid solution. The result shows that the average recoveries for lead, cadmiun, nickel, and chromiun were 100.4%, 99.4%, 95.0%, and 94.0%, respectively. Verified by the standard samples GBW07406 and GBW07407, the established method was found to have a good accuracy. In compariaon with the traditional digestion method, the established method in this atudy was proved to have better accuracy and precision. This method was also proved to have good operability and it's easy to spread.
2012, 40(12): 1952-1953
doi: 10.3724/SP.J.1096.2012.20901
Abstract:
A solvent extraction method was developed for the determination of blueberry anthocyanins. The blueberries samples were coarse extracted twice by acid ethanol. After purificated by the AB-8 macroporous resin, the blueberries extract was vacuum dried. The components of blueberries extract were identified by FeCl3 color reaction and neutral acetic acid lead reaction, and then determined by infrared spectrometry and UV-vis method. The total content of anthocyanins was calculated by pH differential method following by the equation: produce=absorbency×the diluted times of determination spectrophotometry from samples/the quality (g). The results show that the extract of blueberry is part of flavonoids, the extract content is 2.29 mg/g, and the color value is 36.
A solvent extraction method was developed for the determination of blueberry anthocyanins. The blueberries samples were coarse extracted twice by acid ethanol. After purificated by the AB-8 macroporous resin, the blueberries extract was vacuum dried. The components of blueberries extract were identified by FeCl3 color reaction and neutral acetic acid lead reaction, and then determined by infrared spectrometry and UV-vis method. The total content of anthocyanins was calculated by pH differential method following by the equation: produce=absorbency×the diluted times of determination spectrophotometry from samples/the quality (g). The results show that the extract of blueberry is part of flavonoids, the extract content is 2.29 mg/g, and the color value is 36.
