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2017 Volume 45 Issue 5
2017, 45(5): 627-632
doi: 10.11895/j.issn.0253-3820.160902
Abstract:
A rapid and simple method for the determination of cyanide in blood was developed based on pinhole shell-isolated nanoparticles (pinSHINs)-enhanced Raman spectroscopy and an online lysis-purging and trapping approach. In the online lysis-purging and trapping device, the bound cyanide in blood can be cleaved through sulfuric acid acidification, and transferred into HCN volatile gas, then purged into alkaline solution to form NaCN solution, thus high-efficient liberation and entrapment of cyanide from the methemoglobin-bound form can be achieved. The pinSHINs substrate is quite stable to weaken the gold-dissolution effect caused by cyanide under strong alkaline condition, and therefore the detection window can be prolonged to 1 h comparing with 5 min of AuNPs. A limit of detection down to 10 μg/L and a linear range from 100-2000 μg/L in blood were achieved in this method. This method was further applied to rapid measurement of blood samples of cyanide exposed rats and clinic poisoned patients, which provided a sensitive, selective and reliable way for rapid detection of cyanide poisoning.
A rapid and simple method for the determination of cyanide in blood was developed based on pinhole shell-isolated nanoparticles (pinSHINs)-enhanced Raman spectroscopy and an online lysis-purging and trapping approach. In the online lysis-purging and trapping device, the bound cyanide in blood can be cleaved through sulfuric acid acidification, and transferred into HCN volatile gas, then purged into alkaline solution to form NaCN solution, thus high-efficient liberation and entrapment of cyanide from the methemoglobin-bound form can be achieved. The pinSHINs substrate is quite stable to weaken the gold-dissolution effect caused by cyanide under strong alkaline condition, and therefore the detection window can be prolonged to 1 h comparing with 5 min of AuNPs. A limit of detection down to 10 μg/L and a linear range from 100-2000 μg/L in blood were achieved in this method. This method was further applied to rapid measurement of blood samples of cyanide exposed rats and clinic poisoned patients, which provided a sensitive, selective and reliable way for rapid detection of cyanide poisoning.
2017, 45(5): 633-640
doi: 10.11895/j.issn.0253-3820.170020
Abstract:
Air born fine particulate matter (PM2.5) pollution is a serious environmental problem, and it is very important to study the toxicity effect and mechanism of PM2.5. In this study, a liquid chromatography-mass spectrometric (LC-MS) method on the basis of metabolomics technique was developed to investigate the metabolic disruption effect and reproductive toxicity mechanism of PM2.5 on rat testis. The profile of aqueous and organic testis metabolic extracts were acquired, and then analyzed by partial least square-discriminant analysis and nonparametric test. The results showed that control group and treatment group were clearly discriminated in the scoring plot of PLS-DA models, indicating PM2.5 treatment induced significant difference in testis metabolome. A total of 56 differential metabolites were identified, and further pathway analysis suggested that PM2.5 exposure induced amino acid and nucleotide metabolism disorder, steroid hormone metabolism imbalance and abnormal lipid metabolism. These important pathways may be the key molecular events in the PM2.5 reproductive toxicity.
Air born fine particulate matter (PM2.5) pollution is a serious environmental problem, and it is very important to study the toxicity effect and mechanism of PM2.5. In this study, a liquid chromatography-mass spectrometric (LC-MS) method on the basis of metabolomics technique was developed to investigate the metabolic disruption effect and reproductive toxicity mechanism of PM2.5 on rat testis. The profile of aqueous and organic testis metabolic extracts were acquired, and then analyzed by partial least square-discriminant analysis and nonparametric test. The results showed that control group and treatment group were clearly discriminated in the scoring plot of PLS-DA models, indicating PM2.5 treatment induced significant difference in testis metabolome. A total of 56 differential metabolites were identified, and further pathway analysis suggested that PM2.5 exposure induced amino acid and nucleotide metabolism disorder, steroid hormone metabolism imbalance and abnormal lipid metabolism. These important pathways may be the key molecular events in the PM2.5 reproductive toxicity.
2017, 45(5): 641-647
doi: 10.11895/j.issn.0253-3820.160748
Abstract:
The effects of fucoidan on the lipidomics profiling of juvenile yellow catfish (pelteobagrus fulvidraco) during different feeding time (week 1, week 2, week 3 and week 8) were investigated by ultra-performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UPLC-Q-TOF-MS) combined with multivariate data analysis, e.g. principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA). Based on VIP and p values, 11 lipid biomarkers were screened including lysophosphatidylcholine (Lyso-PC) 16∶0, phosphatidylcholine (PC) 22∶6/16∶0, phosphatidylethanolamine (PE) 22∶6/16∶0, phosphatidylinositol (PI) 18∶0/22∶6, diacylglycerol (DAG) 16∶0/16∶0,DAG 16∶0/18∶1, DAG 18∶1/18∶1, triglycerides (TAG) 20∶5/16∶0/18∶3, TAG 20∶4/16∶1/18∶2, TAG 16∶0/18∶2/20∶5 and TAG 18∶2/14∶0/18∶1. It was found that Lyso-PC, PC, PE and PI had the largest levels at the eighth week; the levels of DAG were decreased at the second and fourth weeks, and increased at the eighth week. While TAG was different: the content of TAG 18∶2/14∶0/18∶1, TAG 20∶5/16∶0/18∶3 and TAG 20∶4/16∶1/18∶2 increased in response to fucoidan, but TAG 16∶0/18∶2/20∶5 decreased little. Therefore, for juvenile yellow catfish, fucoidan can affect its lipid metabolism, which provides a theoretical basis for investigation of the influence of fucoidan on the response mechanism of lipid metabolism of juvenile yellow catfish.
The effects of fucoidan on the lipidomics profiling of juvenile yellow catfish (pelteobagrus fulvidraco) during different feeding time (week 1, week 2, week 3 and week 8) were investigated by ultra-performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UPLC-Q-TOF-MS) combined with multivariate data analysis, e.g. principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA). Based on VIP and p values, 11 lipid biomarkers were screened including lysophosphatidylcholine (Lyso-PC) 16∶0, phosphatidylcholine (PC) 22∶6/16∶0, phosphatidylethanolamine (PE) 22∶6/16∶0, phosphatidylinositol (PI) 18∶0/22∶6, diacylglycerol (DAG) 16∶0/16∶0,DAG 16∶0/18∶1, DAG 18∶1/18∶1, triglycerides (TAG) 20∶5/16∶0/18∶3, TAG 20∶4/16∶1/18∶2, TAG 16∶0/18∶2/20∶5 and TAG 18∶2/14∶0/18∶1. It was found that Lyso-PC, PC, PE and PI had the largest levels at the eighth week; the levels of DAG were decreased at the second and fourth weeks, and increased at the eighth week. While TAG was different: the content of TAG 18∶2/14∶0/18∶1, TAG 20∶5/16∶0/18∶3 and TAG 20∶4/16∶1/18∶2 increased in response to fucoidan, but TAG 16∶0/18∶2/20∶5 decreased little. Therefore, for juvenile yellow catfish, fucoidan can affect its lipid metabolism, which provides a theoretical basis for investigation of the influence of fucoidan on the response mechanism of lipid metabolism of juvenile yellow catfish.
2017, 45(5): 648-653
doi: 10.11895/j.issn.0253-3820.160747
Abstract:
To improve the water solubility of daidzein, solid inclusion complexes of daidzein with two amino-modified β-cyclodextrins (ACDs), i.e., mono-6-amino-6-deoxy-β-cyclodextrin (NCD) and mono-6-ethylenediamino-6-deoxy-β-cyclodextrin (ENCD), were prepared by the saturated solution method in water under the preparation conditions as follows: the ratio of daidzein/ACD was 3∶1 and the stirring time was 72 h (83% and 67% yields, respectively). The formation of two inclusion complexes was confirmed by x-ray diffractometry (XRD) and themogravimetric (TG) analysis. The inclusion stoichiometry of the inclusion complexes was 1∶1 from the Job plot and their complexation stability constants (KS) were 899.2 and 203.8 L/mol from fluorescence titration, respectively. After formation of inclusion complexes with NCD and ENCD, the water solubility of daidzein was dramatically raised from 8.31 μg/mL to 15.2 and 13.2 mg/mL at 25℃, increasing by 1800-fold and 1500-fold.
To improve the water solubility of daidzein, solid inclusion complexes of daidzein with two amino-modified β-cyclodextrins (ACDs), i.e., mono-6-amino-6-deoxy-β-cyclodextrin (NCD) and mono-6-ethylenediamino-6-deoxy-β-cyclodextrin (ENCD), were prepared by the saturated solution method in water under the preparation conditions as follows: the ratio of daidzein/ACD was 3∶1 and the stirring time was 72 h (83% and 67% yields, respectively). The formation of two inclusion complexes was confirmed by x-ray diffractometry (XRD) and themogravimetric (TG) analysis. The inclusion stoichiometry of the inclusion complexes was 1∶1 from the Job plot and their complexation stability constants (KS) were 899.2 and 203.8 L/mol from fluorescence titration, respectively. After formation of inclusion complexes with NCD and ENCD, the water solubility of daidzein was dramatically raised from 8.31 μg/mL to 15.2 and 13.2 mg/mL at 25℃, increasing by 1800-fold and 1500-fold.
2017, 45(5): 654-661,753
doi: 10.11895/j.issn.0253-3820.160732
Abstract:
Some new types of microemulsion using phospholipids as the main surfactant were prepared for electrokinetic chromatography and the quantitative structure-retention relationship of neutral solutes in these microemulsion electrokinetic chromatography (MEEKC) systems was studied by solvation parameters model. By using dynamic coating capillary, and with dimethyl sulfoxide (DMSO) and dodecyl benzene as the marker of electroosmotic flow and microemulsion droplets, a total of 17 kinds of stable microemulsions containing soybean phospholipids or other surfactants were prepared and the linear salvation energy relationship equations were developed for these MEEKC systems with 26 small neutral compounds. The coefficients of linear solvation energy relationship (LSER) equations were used to evaluate the similarity of two MEEKC systems. Results indicated that LSER characteristics of phospholipids-MEEKC systems were similar to those of other microemulsion systems. The volume and hydrogen bond basicity of solutes were mostly contributed to the retention in MEEKC. The different types and concentration of oil phase had no evident influence on the retention.
Some new types of microemulsion using phospholipids as the main surfactant were prepared for electrokinetic chromatography and the quantitative structure-retention relationship of neutral solutes in these microemulsion electrokinetic chromatography (MEEKC) systems was studied by solvation parameters model. By using dynamic coating capillary, and with dimethyl sulfoxide (DMSO) and dodecyl benzene as the marker of electroosmotic flow and microemulsion droplets, a total of 17 kinds of stable microemulsions containing soybean phospholipids or other surfactants were prepared and the linear salvation energy relationship equations were developed for these MEEKC systems with 26 small neutral compounds. The coefficients of linear solvation energy relationship (LSER) equations were used to evaluate the similarity of two MEEKC systems. Results indicated that LSER characteristics of phospholipids-MEEKC systems were similar to those of other microemulsion systems. The volume and hydrogen bond basicity of solutes were mostly contributed to the retention in MEEKC. The different types and concentration of oil phase had no evident influence on the retention.
2017, 45(5): 662-667
doi: 10.11895/j.issn.0253-3820.160799
Abstract:
Fluorescence spectroscopy was used to investigate the efficiency of coupling peptides to gold nanoparticles via 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride-N-hydroxysuccinimide (EDC-NHS). The experiment conditions including buffer solution, pH value and concentrations of buffer solution, concentrations of NHS and EDC, concentration ratios of NHS to EDC, and coupling reaction time on the coupling efficiency were investigated and optimized. The experimental results indicated that the optimized experimental conditions were as follows: 25 mmol/L HEPES buffer solution, pH 7.0; 2∶1 of concentration ratio of NHS to EDC, 0.4 mol/L NHS, 0.2 mol/L EDC, and coupling reaction time of 24 h. This study may provide references for the relative research involving coupling peptide or protein with gold nanoparticles
Fluorescence spectroscopy was used to investigate the efficiency of coupling peptides to gold nanoparticles via 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride-N-hydroxysuccinimide (EDC-NHS). The experiment conditions including buffer solution, pH value and concentrations of buffer solution, concentrations of NHS and EDC, concentration ratios of NHS to EDC, and coupling reaction time on the coupling efficiency were investigated and optimized. The experimental results indicated that the optimized experimental conditions were as follows: 25 mmol/L HEPES buffer solution, pH 7.0; 2∶1 of concentration ratio of NHS to EDC, 0.4 mol/L NHS, 0.2 mol/L EDC, and coupling reaction time of 24 h. This study may provide references for the relative research involving coupling peptide or protein with gold nanoparticles
2017, 45(5): 668-673
doi: 10.11895/j.issn.0253-3820.170025
Abstract:
Aquatic plant duckweed can enrich high concentration of arsenic, it is thus used as the representative of phytofiltration. The mechanism of arsenic tolerance in duckweeds has received much concern. In this study, synchrotron radiation X-ray fluorescence (SRXRF) and X-ray absorption near edge structure (XANES) techniques were used to study the micro-distribution and speciation of arsenic in natural As-rich duckweed from lead-zinc mine. Two monolithic duckweeds, FP1 and FP2, were analyzed by micro SRXRF, setting single point scan time and spot size were 5 s, 70 μm×80 μm and 2 s, 100 μm×100 μm respectively. Six points of FP2 were selected and analyzed by micro XANES in energy range of 11.81-11.96 keV. Pressed-pellet duckweed was analyzed by bulk XANES in energy range of 11.67-12.27 keV. The result showed that As(Ⅲ) was the major speciation of duckweed from bulk XANES and micro-XANES data. SRXRF micro analysis showed that arsenic had significant vein distribution in duckweed, and was not spread into the photosynthetic mesophyll within certain concentration, which may reduce the leaf toxicity triggered by arsenic. This vein distribution may play a role in arsenic tolerance in duckweed.
Aquatic plant duckweed can enrich high concentration of arsenic, it is thus used as the representative of phytofiltration. The mechanism of arsenic tolerance in duckweeds has received much concern. In this study, synchrotron radiation X-ray fluorescence (SRXRF) and X-ray absorption near edge structure (XANES) techniques were used to study the micro-distribution and speciation of arsenic in natural As-rich duckweed from lead-zinc mine. Two monolithic duckweeds, FP1 and FP2, were analyzed by micro SRXRF, setting single point scan time and spot size were 5 s, 70 μm×80 μm and 2 s, 100 μm×100 μm respectively. Six points of FP2 were selected and analyzed by micro XANES in energy range of 11.81-11.96 keV. Pressed-pellet duckweed was analyzed by bulk XANES in energy range of 11.67-12.27 keV. The result showed that As(Ⅲ) was the major speciation of duckweed from bulk XANES and micro-XANES data. SRXRF micro analysis showed that arsenic had significant vein distribution in duckweed, and was not spread into the photosynthetic mesophyll within certain concentration, which may reduce the leaf toxicity triggered by arsenic. This vein distribution may play a role in arsenic tolerance in duckweed.
2017, 45(5): 674-680
doi: 10.11895/j.issn.0253-3820.160863
Abstract:
Three commonly used ionization techniques, including electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and atmospheric pressure photoionization (APPI) were compared systemically for their ionization ability, sensitivity and coverage for detecting lipids, aiming to explore their applicability in lipidomics study of serum samples. Serum samples were pretreated by liquid-liquid extraction with methyl tertiary butyl ether and then introduced into a LC-MS system equipped with electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and atmospheric pressure photoionization (APPI) source. Chromatographic separation was performed on an Ascentiss Express C8 column (150 mm×2.1 mm, 2.7 μm). A binary gradient system of acetonitrile-water (3∶2, V/V) and isoropyl alcohol-acetonitrile (9∶1, V/V), both containing 10 mmol/L ammonium formate and 0.1% formic acid, was used as eluent A and B, respectively. Data were acquired in both positive and negative ion modes for each ionization technique. The results showed that fatty acids (FFAs), phospholipids (PLs), sphingophosphalipids (SPs), glycerolipids (GLs), could be ionized most efficiently under ESI source, while APPI source gave the best sensitivity for cholesterol (CHOL), cholesterol esters (CEs) and Sphinganine (Sphingolipids, SPs). Prenol lipids could be ionized equally well under ESI and APPI source, and that the application of ESI and APPI integrated approach was expected to enhance the overall sensitivity of the method and provided more comprehensive lipids information for the global serum lipidomics study.
Three commonly used ionization techniques, including electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and atmospheric pressure photoionization (APPI) were compared systemically for their ionization ability, sensitivity and coverage for detecting lipids, aiming to explore their applicability in lipidomics study of serum samples. Serum samples were pretreated by liquid-liquid extraction with methyl tertiary butyl ether and then introduced into a LC-MS system equipped with electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and atmospheric pressure photoionization (APPI) source. Chromatographic separation was performed on an Ascentiss Express C8 column (150 mm×2.1 mm, 2.7 μm). A binary gradient system of acetonitrile-water (3∶2, V/V) and isoropyl alcohol-acetonitrile (9∶1, V/V), both containing 10 mmol/L ammonium formate and 0.1% formic acid, was used as eluent A and B, respectively. Data were acquired in both positive and negative ion modes for each ionization technique. The results showed that fatty acids (FFAs), phospholipids (PLs), sphingophosphalipids (SPs), glycerolipids (GLs), could be ionized most efficiently under ESI source, while APPI source gave the best sensitivity for cholesterol (CHOL), cholesterol esters (CEs) and Sphinganine (Sphingolipids, SPs). Prenol lipids could be ionized equally well under ESI and APPI source, and that the application of ESI and APPI integrated approach was expected to enhance the overall sensitivity of the method and provided more comprehensive lipids information for the global serum lipidomics study.
2017, 45(5): 681-686
doi: 10.11895/j.issn.0253-3820.160750
Abstract:
A high performance liquid chromatography method based on amino column to uncover the glycosyls of aroma glycosides in Meili grape was established. Meili grapes were sampled from Yangling, Shaanxi province, China. Aroma glycosides in grape skins were extracted by extraction buffer (0.1 mol/L Na2HPO4/NaH2PO4, pH 7.0, 13% ethanol (V/V)), then enzymatically hydrolysed by AR2000 enzyme preparation in citrate-phosphate buffer (pH 5.0), and the glycosyls liberated were isolated by amino column, and determined by high performance liquid chromatography-refractive index detector (HPLC-RID). The HPLC-RID experimental conditions were developed as follows: amino column temperature 35℃, RID temperature 35℃, injection volume 20 μL, mobile phase acetonitrile/ethyl acetate/water=60∶25∶15 (V/V), flow rate 1 mL/min. The results showed that the reasonable linearity was achieved for rhamnose, xylose, arabinose, apiose and glucose (R2>0.996), with the detection limit (LOD) of 93-123 mg/L and quantitation limit (LOQ) of 309-409 mg/L. The relative standard deviation (RSD, n=10) of the peaks of each monosaccharide (5 g/L) was 2.3%-6.4%, and the recoveries ranged from 73.8% to 125.7%. The molar percentages of the aroma glycosides in Meili grape were 4.1%-6.1% for 6-O-α-L-rhamnopyranosyl-β-D-glucopyranoside, 2.3%-8.8% for 6-O-β-D-xylopyranosyl-β-D-glucopyranoside, 0.1%-3.9% for 6-O-α-L-arabinofuranosyl-β-D-glucopyranoside, 5.5%-9.8% for 6-O-α-L-apiofuranosyl-β-D-glucopyranoside, and 76.3%-86.8% for 6-O-β-D-glucopyranosyl-β-D-glucopyranoside. The contents of each aroma glycoside and the total glycosides in Meili grape didn't show obvious relationship with berry maturity index during grape maturity.
A high performance liquid chromatography method based on amino column to uncover the glycosyls of aroma glycosides in Meili grape was established. Meili grapes were sampled from Yangling, Shaanxi province, China. Aroma glycosides in grape skins were extracted by extraction buffer (0.1 mol/L Na2HPO4/NaH2PO4, pH 7.0, 13% ethanol (V/V)), then enzymatically hydrolysed by AR2000 enzyme preparation in citrate-phosphate buffer (pH 5.0), and the glycosyls liberated were isolated by amino column, and determined by high performance liquid chromatography-refractive index detector (HPLC-RID). The HPLC-RID experimental conditions were developed as follows: amino column temperature 35℃, RID temperature 35℃, injection volume 20 μL, mobile phase acetonitrile/ethyl acetate/water=60∶25∶15 (V/V), flow rate 1 mL/min. The results showed that the reasonable linearity was achieved for rhamnose, xylose, arabinose, apiose and glucose (R2>0.996), with the detection limit (LOD) of 93-123 mg/L and quantitation limit (LOQ) of 309-409 mg/L. The relative standard deviation (RSD, n=10) of the peaks of each monosaccharide (5 g/L) was 2.3%-6.4%, and the recoveries ranged from 73.8% to 125.7%. The molar percentages of the aroma glycosides in Meili grape were 4.1%-6.1% for 6-O-α-L-rhamnopyranosyl-β-D-glucopyranoside, 2.3%-8.8% for 6-O-β-D-xylopyranosyl-β-D-glucopyranoside, 0.1%-3.9% for 6-O-α-L-arabinofuranosyl-β-D-glucopyranoside, 5.5%-9.8% for 6-O-α-L-apiofuranosyl-β-D-glucopyranoside, and 76.3%-86.8% for 6-O-β-D-glucopyranosyl-β-D-glucopyranoside. The contents of each aroma glycoside and the total glycosides in Meili grape didn't show obvious relationship with berry maturity index during grape maturity.
2017, 45(5): 687-692
doi: 10.11895/j.issn.0253-3820.160767
Abstract:
Waste printed circuit boards(W-PCBs) were multiple smashed and separated, then passed through a 60-mesh screen, treated with hydrochloric acid (2 mol/L), ultrapure water and dehydrated with acetone successively. The filter residue and filter paper were filled into the extraction pool, or inserted into Soxhlet Extraction tube parceled with new filter paper. After addition of 5 μL of internal standard substance, the filter residue above was respectively extracted by Soxhlet Extraction (SE) method or Accelerated Solvent Extraction (ASE) method, cleaned with multi-layer silica gel column and activated-charcoal column to obtained the dioxins samples. The samples were analyzed by isotope dilution high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS). The effects of SE and ASE method and number of chlorines atoms on recovery of 15 kinds of 13C-2,3,7,8 PCDD/Fs were investigated, and the accuracy and precision of the two extraction methods were compared. The results show that, the recovery of 15 kinds of 13C-2,3,7,8 PCDD/Fs using ASE method is 54.3%-113.0%, and that of SE is 28.3%-77.7%, and the Toxic Equivalent Quangtity (TEQ) in W-PCBs is 0.075 ng/kg (TEQ) and 0.266 ng/kg (TEQ) using ASE and SE method respectively. Under the premise that accuracy and precision meet with the international standard, ASE is simple, rapid, solvent-free and accurate.
Waste printed circuit boards(W-PCBs) were multiple smashed and separated, then passed through a 60-mesh screen, treated with hydrochloric acid (2 mol/L), ultrapure water and dehydrated with acetone successively. The filter residue and filter paper were filled into the extraction pool, or inserted into Soxhlet Extraction tube parceled with new filter paper. After addition of 5 μL of internal standard substance, the filter residue above was respectively extracted by Soxhlet Extraction (SE) method or Accelerated Solvent Extraction (ASE) method, cleaned with multi-layer silica gel column and activated-charcoal column to obtained the dioxins samples. The samples were analyzed by isotope dilution high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS). The effects of SE and ASE method and number of chlorines atoms on recovery of 15 kinds of 13C-2,3,7,8 PCDD/Fs were investigated, and the accuracy and precision of the two extraction methods were compared. The results show that, the recovery of 15 kinds of 13C-2,3,7,8 PCDD/Fs using ASE method is 54.3%-113.0%, and that of SE is 28.3%-77.7%, and the Toxic Equivalent Quangtity (TEQ) in W-PCBs is 0.075 ng/kg (TEQ) and 0.266 ng/kg (TEQ) using ASE and SE method respectively. Under the premise that accuracy and precision meet with the international standard, ASE is simple, rapid, solvent-free and accurate.
2017, 45(5): 693-699
doi: 10.11895/j.issn.0253-3820.160864
Abstract:
Chemical analysis and bioassay were used to distinguish quality grades of Salvia miltiorrhiza bge., and the active compounds were investigated on anti-platelet aggregation. We established the HPLC fingerprint of Salvia miltiorrhiza bge. and meansured thir biopotency based on anti-platelet aggregation. The results showed that the HPLC fingerprints of different batches of Salvia miltiorrhiza bge. were similar (Similarity=0.930-0.998), but the difference of biopotency could be ten-fold. Through correlation analysis of chemical fingerprint and anti-platelet aggregation assay, dihydrotanshinone Ⅰ, cryptotanshinone, tanshinone Ⅰ, tanshinone ⅡA, and two unknown compounds were closely related to the biopotency. It was proved that cryptotanshinone was a high activity component on platelet aggregation. To compare the active contribution of the high content Salvianolic acid B and low content of the active ingredient cryptotanshinone, the active contribution value of the two compounds were basically equivalent. Cryptotanshinone, which had low content but high activity, made an important contribution to evaluating the quality of Salvia miltiorrhiza bge.. The results indicated that the quality of traditional Chinese medicine could not be evaluated accurately by only using the chemical content or abundance. This work established a quality evaluation model based on chemical fingerprint and bioassay which could improve the quality evaluation of traditional Chinese medicine associating with effects.
Chemical analysis and bioassay were used to distinguish quality grades of Salvia miltiorrhiza bge., and the active compounds were investigated on anti-platelet aggregation. We established the HPLC fingerprint of Salvia miltiorrhiza bge. and meansured thir biopotency based on anti-platelet aggregation. The results showed that the HPLC fingerprints of different batches of Salvia miltiorrhiza bge. were similar (Similarity=0.930-0.998), but the difference of biopotency could be ten-fold. Through correlation analysis of chemical fingerprint and anti-platelet aggregation assay, dihydrotanshinone Ⅰ, cryptotanshinone, tanshinone Ⅰ, tanshinone ⅡA, and two unknown compounds were closely related to the biopotency. It was proved that cryptotanshinone was a high activity component on platelet aggregation. To compare the active contribution of the high content Salvianolic acid B and low content of the active ingredient cryptotanshinone, the active contribution value of the two compounds were basically equivalent. Cryptotanshinone, which had low content but high activity, made an important contribution to evaluating the quality of Salvia miltiorrhiza bge.. The results indicated that the quality of traditional Chinese medicine could not be evaluated accurately by only using the chemical content or abundance. This work established a quality evaluation model based on chemical fingerprint and bioassay which could improve the quality evaluation of traditional Chinese medicine associating with effects.
2017, 45(5): 700-706
doi: 10.11895/j.issn.0253-3820.160873
Abstract:
Harpagoside (HAR) is believed to be a main compound in Scrophularia ningpoensis which possess a broad of biological activities. Human serum albumin (HSA) has important physiological roles in transportation, distribution and metabolism of many endogenous and exogenous substances in body. It is great significance in pharmacology to investigate the interaction mechanism of HAR and HSA. In this work, the interaction between HAR and HSA was investigated by fluorescence and ultraviolet absorption spectroscopy at different pH (pH=4.0, 7.4, and 9.0) and temperatures (297, 310 and 323 K). The experimental results showed that the HAR could cause the fluorescence quenching of HSA through a static quenching procedure, showing that the HAR regularly quenched the intrinsic fluorescence of HSA, and a decrease in the quenching constant was observed with an increase in temperature. Under different conditions, all the magnitude of binding constants (KA) was larger than 105 L/mol and the number of binding sites (n) in the binary system were approximate to 1. Base on the magnitude of enthalpy and entropy changes, the negative values of ΔG, ΔH and ΔS revealed that the binding of HAR with HSA was spontaneous and exothermic process, and the main interaction forces of the HAR with HAR were van der Waals forces and/or hydrogen bonding interaction. The binding distance (r) between the HAR and HSA was calculated to be about 4.2 nm based on the theory of Frster's nonradiation energy transfer, which indicated that the energy transfer from HSA to HAR occurred with high possibility. What was more, the synchronous florescence spectroscopy confirmed the conformational changes of HSA during the binding reaction.
Harpagoside (HAR) is believed to be a main compound in Scrophularia ningpoensis which possess a broad of biological activities. Human serum albumin (HSA) has important physiological roles in transportation, distribution and metabolism of many endogenous and exogenous substances in body. It is great significance in pharmacology to investigate the interaction mechanism of HAR and HSA. In this work, the interaction between HAR and HSA was investigated by fluorescence and ultraviolet absorption spectroscopy at different pH (pH=4.0, 7.4, and 9.0) and temperatures (297, 310 and 323 K). The experimental results showed that the HAR could cause the fluorescence quenching of HSA through a static quenching procedure, showing that the HAR regularly quenched the intrinsic fluorescence of HSA, and a decrease in the quenching constant was observed with an increase in temperature. Under different conditions, all the magnitude of binding constants (KA) was larger than 105 L/mol and the number of binding sites (n) in the binary system were approximate to 1. Base on the magnitude of enthalpy and entropy changes, the negative values of ΔG, ΔH and ΔS revealed that the binding of HAR with HSA was spontaneous and exothermic process, and the main interaction forces of the HAR with HAR were van der Waals forces and/or hydrogen bonding interaction. The binding distance (r) between the HAR and HSA was calculated to be about 4.2 nm based on the theory of Frster's nonradiation energy transfer, which indicated that the energy transfer from HSA to HAR occurred with high possibility. What was more, the synchronous florescence spectroscopy confirmed the conformational changes of HSA during the binding reaction.
2017, 45(5): 707-712
doi: 10.11895/j.issn.0253-3820.160862
Abstract:
A method for the determination of caffeine in urea was developed based on bubble-in-drop single drop microextraction (BID-SDME) followed by gas chromatography/mass spectrometry (GC-MS). Under the optimum conditions including chloroform as extraction solvent, an exposure volume of 1 μL, a bubble volume of 1.6 μL, stirring for 5 min at 300 r/min, 15% (m/V) NaCl, and a distance of 1 cm between bubble and stirring bar, the detection limit of this method was as low as 0.003 mg/L and the linear range was from 0.005 mg/L to 10 mg/L with correlation coefficient of 0.982. The recoveries of caffeine were from 89.2% to 107.5% at different spiked levels in human urine and the relative standard deviation (RSD, n=6) was less than 8%.
A method for the determination of caffeine in urea was developed based on bubble-in-drop single drop microextraction (BID-SDME) followed by gas chromatography/mass spectrometry (GC-MS). Under the optimum conditions including chloroform as extraction solvent, an exposure volume of 1 μL, a bubble volume of 1.6 μL, stirring for 5 min at 300 r/min, 15% (m/V) NaCl, and a distance of 1 cm between bubble and stirring bar, the detection limit of this method was as low as 0.003 mg/L and the linear range was from 0.005 mg/L to 10 mg/L with correlation coefficient of 0.982. The recoveries of caffeine were from 89.2% to 107.5% at different spiked levels in human urine and the relative standard deviation (RSD, n=6) was less than 8%.
2017, 45(5): 713-720
doi: 10.11895/j.issn.0253-3820.160768
Abstract:
A glassy carbon electrode (GCE) modified with gold nanoparticles loading on the reduced graphene oxide (rGO)-multi-walled carbon nanotubes (MWCNTs) composite film was fabricated by a two-step procedure. Firstly, rGO-MWCNTs composite were prepared by in-situ chemical reduction method with hydrazine as a reducing agent. Then, AuNPs were deposited on the surface of rGO-MWCNTs using simple cyclic voltammetry. This modified electrode was characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and electrochemical methods. Furthermore, the electrochemical behavior of bisphenol A (BPA) was also investigated using this modified electrode. The results showed that the modified electrode had high electrochemical activity for the oxidation of BPA. In 0.10 mol/L phosphate buffer solution (PBS, pH 7.0), the linear range for the determination of BPA with differential pulse voltammetry (DPV) was in the range of 5.0 × 10-9 -1.0 × 10-7 mol/L and 1.0 × 10-7-2.0 × 10-5 mol/L. The detection limit was 1.0 × 10-9 mol/L (S/N=3). The as-prepared modified electrode was successfully used to determine BPA in river water and the shopping receipt samples with recovery ranges of 97%-110% and 98%-104%, respectively.
A glassy carbon electrode (GCE) modified with gold nanoparticles loading on the reduced graphene oxide (rGO)-multi-walled carbon nanotubes (MWCNTs) composite film was fabricated by a two-step procedure. Firstly, rGO-MWCNTs composite were prepared by in-situ chemical reduction method with hydrazine as a reducing agent. Then, AuNPs were deposited on the surface of rGO-MWCNTs using simple cyclic voltammetry. This modified electrode was characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and electrochemical methods. Furthermore, the electrochemical behavior of bisphenol A (BPA) was also investigated using this modified electrode. The results showed that the modified electrode had high electrochemical activity for the oxidation of BPA. In 0.10 mol/L phosphate buffer solution (PBS, pH 7.0), the linear range for the determination of BPA with differential pulse voltammetry (DPV) was in the range of 5.0 × 10-9 -1.0 × 10-7 mol/L and 1.0 × 10-7-2.0 × 10-5 mol/L. The detection limit was 1.0 × 10-9 mol/L (S/N=3). The as-prepared modified electrode was successfully used to determine BPA in river water and the shopping receipt samples with recovery ranges of 97%-110% and 98%-104%, respectively.
2017, 45(5): 721-726
doi: 10.11895/j.issn.0253-3820.160645
Abstract:
A reusable chronocoulometric adenosine triphosphate (ATP)-aptamer sensor was developed in this work. A short chain of DNA marked as cDNA containing complementary sequence was immobilized on gold electrode based on Au-S self-assembly. The ATP aptamer was hybridized with cDNA. The surface-confined DNA could bind with ［Ru(NH3)6]3+ (RuHex) in the electrolyte via electrostatic interaction. Upon target ATP binding, the aptamer confined onto electrode surface was disassociated from the cDNA oligonucleotides into the solution. Such surface density change of DNA lead to the decrease of chronocoulometric signal for the RuHex which confined on the electrode surface. The chronocoulometric signals showed a linear relationship with logrithm of ATP concentration in the range of 1 nmol/L to 100 μmol/L, and the detection limit of this aptamer sensor could reach 0.5 nmol/L (S/N=3). This aptamer sensor could be regenerated 5 times by simple steps. With this aptamer sensor, the basal level of ATP in the brain cortex micorodialysate was determined to be 19.2±3.7 nmol/L (n=3).
A reusable chronocoulometric adenosine triphosphate (ATP)-aptamer sensor was developed in this work. A short chain of DNA marked as cDNA containing complementary sequence was immobilized on gold electrode based on Au-S self-assembly. The ATP aptamer was hybridized with cDNA. The surface-confined DNA could bind with ［Ru(NH3)6]3+ (RuHex) in the electrolyte via electrostatic interaction. Upon target ATP binding, the aptamer confined onto electrode surface was disassociated from the cDNA oligonucleotides into the solution. Such surface density change of DNA lead to the decrease of chronocoulometric signal for the RuHex which confined on the electrode surface. The chronocoulometric signals showed a linear relationship with logrithm of ATP concentration in the range of 1 nmol/L to 100 μmol/L, and the detection limit of this aptamer sensor could reach 0.5 nmol/L (S/N=3). This aptamer sensor could be regenerated 5 times by simple steps. With this aptamer sensor, the basal level of ATP in the brain cortex micorodialysate was determined to be 19.2±3.7 nmol/L (n=3).
2017, 45(5): 727-733
doi: 10.11895/j.issn.0253-3820.160771
Abstract:
A molecularly imprinted two-dimensional photonic crystal hydrogel sensor was developed with erythromycin as imprinted molecule, polystyrene two-dimensional photonic crystal as templates, methanol as solvent, methacrylic acid as monomers and ethylene glycol dimethylacrylate as cross-linkers. The imprinted molecule was removed by methanol/acetic acid (9∶1, V/V). The results showed that the diameter of Debye ring increased 6 mm when the concentration of EM changed from 0 to 1×10-6 mol/L. Namely the lattice spacing decreased 30 nm. In addition, the diameter of Debye ring only increased 1.5 and 2.0 mm when the hydrogel immersed in 1×10-6 mol/L roxithromycin (RM) or erythromycin ethylsuccinate (EEs) solution. The result indicated that the sensor had high selectivity and could be used in determination of erythromycin with low cost and easy operation.
A molecularly imprinted two-dimensional photonic crystal hydrogel sensor was developed with erythromycin as imprinted molecule, polystyrene two-dimensional photonic crystal as templates, methanol as solvent, methacrylic acid as monomers and ethylene glycol dimethylacrylate as cross-linkers. The imprinted molecule was removed by methanol/acetic acid (9∶1, V/V). The results showed that the diameter of Debye ring increased 6 mm when the concentration of EM changed from 0 to 1×10-6 mol/L. Namely the lattice spacing decreased 30 nm. In addition, the diameter of Debye ring only increased 1.5 and 2.0 mm when the hydrogel immersed in 1×10-6 mol/L roxithromycin (RM) or erythromycin ethylsuccinate (EEs) solution. The result indicated that the sensor had high selectivity and could be used in determination of erythromycin with low cost and easy operation.
2017, 45(5): 734-740
doi: 10.11895/j.issn.0253-3820.160787
Abstract:
2-(Dimethylamino)ethyl methacrylate and sodium monochloroacetate were employed to synthesize [2-(Methacryloyloxy)ethyl] dimethyl ammonium acetate (CBMA) functional monomer. CBMA was grafted on the surface of silica by surface initiated atom transfer radical polymerization (SI-ATRP) to obtain silica-CBMA hydrophilic interaction stationary phase. Three silica-CBMA stationary phases with different grafted density of CBMA monomer were synthesized in SI-ATRP progress by changing the concentration of CBMA under the same conditions. The ability to separate organic acid compounds of the synthesized silica-CBMA stationary phases was evaluated under different conditions, including effects of pH value, salt concentration and content of water of mobile phase on retention of solutes. The results showed that the stationary phases could effectively separate organic acid compounds in HILIC mode, which followed a mixed mode of chromatography of ion exchange and hydrophilic interaction. The retention of solutes decreased with the increases of salt concentration of mobile phase, which consistent with the characteristics of ion exchange; the pH value of mobile phase had significant influence on ionization of the stationary phase and solutes, i.e., the retention of solutes increased as the increasing of pH value of mobile phase. However, the retention of solutes decreased with the increasing of the content of water in mobile phase, which was the typical characteristic of HILIC. The method of hydrophilic interaction chromatography combined with silica-CBMA stationary phases could conveniently determinate the content of vitamin C and rutin in rutin tablets, providing a new method for the separation and determination of strong polar samples.
2-(Dimethylamino)ethyl methacrylate and sodium monochloroacetate were employed to synthesize [2-(Methacryloyloxy)ethyl] dimethyl ammonium acetate (CBMA) functional monomer. CBMA was grafted on the surface of silica by surface initiated atom transfer radical polymerization (SI-ATRP) to obtain silica-CBMA hydrophilic interaction stationary phase. Three silica-CBMA stationary phases with different grafted density of CBMA monomer were synthesized in SI-ATRP progress by changing the concentration of CBMA under the same conditions. The ability to separate organic acid compounds of the synthesized silica-CBMA stationary phases was evaluated under different conditions, including effects of pH value, salt concentration and content of water of mobile phase on retention of solutes. The results showed that the stationary phases could effectively separate organic acid compounds in HILIC mode, which followed a mixed mode of chromatography of ion exchange and hydrophilic interaction. The retention of solutes decreased with the increases of salt concentration of mobile phase, which consistent with the characteristics of ion exchange; the pH value of mobile phase had significant influence on ionization of the stationary phase and solutes, i.e., the retention of solutes increased as the increasing of pH value of mobile phase. However, the retention of solutes decreased with the increasing of the content of water in mobile phase, which was the typical characteristic of HILIC. The method of hydrophilic interaction chromatography combined with silica-CBMA stationary phases could conveniently determinate the content of vitamin C and rutin in rutin tablets, providing a new method for the separation and determination of strong polar samples.
2017, 45(5): 741-746
doi: 10.11895/j.issn.0253-3820.160320
Abstract:
Molecular simulation was used to study the interaction between template molecule and functional monomer to shorten the optimization time for the functional monomer and the ratio of functional monomer and template molecule. Kaempferol molecularly imprinted polymerization (MIP) monolithic column was therefore synthesized by reversible addition-fragmentation chain-transfer (RAFT) polymerization with dibenzyltrithiocarbonate (DBTTC) and ethyleneglycoldim ethacrylate (EDMA) as RAFT and cross-linking agent, respectively, whereas methacrylic acid (MAA) was the optimal functional monomer with the molar ratio of kaempferol/MAA of 1∶4 from molecular simulation results. The results indicate that molecular simulation is useful to simplify the experimental procedure, and DBTTC as RAFT agent can provide more adjustable and better MIP monolithic column.
Molecular simulation was used to study the interaction between template molecule and functional monomer to shorten the optimization time for the functional monomer and the ratio of functional monomer and template molecule. Kaempferol molecularly imprinted polymerization (MIP) monolithic column was therefore synthesized by reversible addition-fragmentation chain-transfer (RAFT) polymerization with dibenzyltrithiocarbonate (DBTTC) and ethyleneglycoldim ethacrylate (EDMA) as RAFT and cross-linking agent, respectively, whereas methacrylic acid (MAA) was the optimal functional monomer with the molar ratio of kaempferol/MAA of 1∶4 from molecular simulation results. The results indicate that molecular simulation is useful to simplify the experimental procedure, and DBTTC as RAFT agent can provide more adjustable and better MIP monolithic column.
2017, 45(5): 747-753
doi: 10.11895/j.issn.0253-3820.160757
Abstract:
Polyacrylic acid was firstly grafted by N-amino-4-N-methylpiperazine-1,8-naphthlimide (AMN) to prepare a amphiphilic polymer, which was self-assembled in water producing nanoparticles called as PAAMN. Then the morphology, structure and fluorescence properties of PAAMN were investigated by various methods including transmission electron microscopy, dynamic light scattering, ultraviolet-visible spectroscopy (UV-Vis), nuclear magnetic resonance spectroscopy (HNMR) and fluorescence spectroscopy. MTT assay was carried out to assess the cell compatibility of PAAMN. Finally, the fluorescence from PAAMN self and HeLa cells incubated with PAAMN was observed by fluorescence microscope. The results revealed that PAAMN had spherical structure, in which naphthlimide fluorphores were immobilized in the polyacrylic acid matrix with the degree of substitution of 4.1%. Under the physiological pH condition, PAAMN excited at 390 nm could emit strong and stable fluorescence at 534 nm. In the range of pH 4.0-10.0, its excitation and emission wavelengths had no obvious change. The fluorescence intensity of PAAMN increased with the decrease of pH values, but the pH sensitivity of PAAMN was much lower than that of AMN. PAAMN had good cell compatibility. From the pictures of fluorescence imaging, it was found that both PAAMN self and cells-engulfed PAAMN could emit green fluorescence upon excited at 390 nm, indicating the potential of the developed nanoparticle for cell imaging.
Polyacrylic acid was firstly grafted by N-amino-4-N-methylpiperazine-1,8-naphthlimide (AMN) to prepare a amphiphilic polymer, which was self-assembled in water producing nanoparticles called as PAAMN. Then the morphology, structure and fluorescence properties of PAAMN were investigated by various methods including transmission electron microscopy, dynamic light scattering, ultraviolet-visible spectroscopy (UV-Vis), nuclear magnetic resonance spectroscopy (HNMR) and fluorescence spectroscopy. MTT assay was carried out to assess the cell compatibility of PAAMN. Finally, the fluorescence from PAAMN self and HeLa cells incubated with PAAMN was observed by fluorescence microscope. The results revealed that PAAMN had spherical structure, in which naphthlimide fluorphores were immobilized in the polyacrylic acid matrix with the degree of substitution of 4.1%. Under the physiological pH condition, PAAMN excited at 390 nm could emit strong and stable fluorescence at 534 nm. In the range of pH 4.0-10.0, its excitation and emission wavelengths had no obvious change. The fluorescence intensity of PAAMN increased with the decrease of pH values, but the pH sensitivity of PAAMN was much lower than that of AMN. PAAMN had good cell compatibility. From the pictures of fluorescence imaging, it was found that both PAAMN self and cells-engulfed PAAMN could emit green fluorescence upon excited at 390 nm, indicating the potential of the developed nanoparticle for cell imaging.
2017, 45(5): 754-761
doi: 10.11895/j.issn.0253-3820.160834
Abstract:
2,4,6-Trinitrotoluene (TNT) and its by-products dinitrotoluene (DNT) pose a significant threat to human health and other living organisms. However, the conventional analytical methods involved in bulky and expensive instruments are complicated and time-consuming, impeding quick and on-line determination. In this work, a facile yet effective strategy of utilizing UV-vis spectroscopy coupled with partial least squares (PLS) was proposed, through which TNT and two isomers of DNT (2,4-DNT and 2,6-DNT) in nature water could be rapidly and simultaneously determined without any pre-separation. Variable combination population analysis (VCPA) was utilized to select important feather variables and significantly improved the predictive performance of the PLS model. The calibration set contained 25 samples constructed by orthogonal array design (OAD). The predictive ability of the models was validated by an independent prediction set including 15 samples, achieving up to 0.99 of the determination coefficients (R2) for each of the analytes. The optimized models were successfully applied to determine the 3 ingredients in 8 environmental samples involving in tap, lake and two kinds of river water with the recovery values of great than 97%. Finally, the proposed method was further validated by high performance liquid chromatography method. UV-vis spectroscopy coupled with chemometrics may be used as simple and effective strategy with high potential in environmental monitoring.
2,4,6-Trinitrotoluene (TNT) and its by-products dinitrotoluene (DNT) pose a significant threat to human health and other living organisms. However, the conventional analytical methods involved in bulky and expensive instruments are complicated and time-consuming, impeding quick and on-line determination. In this work, a facile yet effective strategy of utilizing UV-vis spectroscopy coupled with partial least squares (PLS) was proposed, through which TNT and two isomers of DNT (2,4-DNT and 2,6-DNT) in nature water could be rapidly and simultaneously determined without any pre-separation. Variable combination population analysis (VCPA) was utilized to select important feather variables and significantly improved the predictive performance of the PLS model. The calibration set contained 25 samples constructed by orthogonal array design (OAD). The predictive ability of the models was validated by an independent prediction set including 15 samples, achieving up to 0.99 of the determination coefficients (R2) for each of the analytes. The optimized models were successfully applied to determine the 3 ingredients in 8 environmental samples involving in tap, lake and two kinds of river water with the recovery values of great than 97%. Finally, the proposed method was further validated by high performance liquid chromatography method. UV-vis spectroscopy coupled with chemometrics may be used as simple and effective strategy with high potential in environmental monitoring.
2017, 45(5): 762-769
doi: 10.11895/j.issn.0253-3820.170016
Abstract:
Fe3O4-grafted nitrogen-doped graphene (Fe3O4/N-G) nanomaterials were synthesized by chemical co-precipitation method, and its adsorption properties were discussed preliminarily. It was demonstrated that the adsorption of parachlormetaxylenol on Fe3O4/N-G was not limited to uniform monolayer adsorption and the adsorption kinetic followed the pseudo-second-order kinetic mode. Then, an ultrasound-assisted magnetic solid-phase extraction with Fe3O4/N-G as the magnetic adsorbent has been developed for the determination of four compounds including triclosan, chloroxylenol, hexachlorobenzene and 2,2',4,4',5,5'-hexachlorobiphenyl in environmental water samples, in combination with gas chromatography coupled to tandem mass spectrometry. Several factors related to extraction efficiencies, such as the amount of adsorbent, extraction time, sample pH and desorption conditions were investigated. The proposed preparation procedure was as follows: 6.0 mg of Fe3O4/N-G was dispersed into 100 mL of water sample under ultrasound. After 15 s, the Fe3O4/N-G carrying four compounds was separated from the water sample by an external magnetic field. Then, the targets were eluted from Fe3O4/N-G with 3 mL of ethanol and 2 mL of dichloromethane, sequentially. Finally, the eluent was dried under a mild stream of nitrogen and reconstituted with methanol and dichloromethane (1∶1, V/V) for the subsequent GC-MS/MS analysis. Under the optimized condition, an excellent linearity was observed in the range of 0.1-10 ng/L for the four compounds, with the correlation coefficients ranging from 0.9983 to 0.9999. The limits of detections (S/N=3) ranged from 0.05 to 0.6 ng/L and the limits of quantity (S/N=10) ranged from 0.2 to 2.4 ng/L. The mean recoveries at three spiked levels ranged from 68.2% to 99.6%. The relative standard deviations (RSDs) of intraday and interday were in the range of 3.3%-6.9% and 3.4%-9.4% (n=6), respectively. The proposed method was demonstrated to be simple and feasible for the trace analysis of antimicrobial agents and organochlorine contaminants in environmental water samples.
Fe3O4-grafted nitrogen-doped graphene (Fe3O4/N-G) nanomaterials were synthesized by chemical co-precipitation method, and its adsorption properties were discussed preliminarily. It was demonstrated that the adsorption of parachlormetaxylenol on Fe3O4/N-G was not limited to uniform monolayer adsorption and the adsorption kinetic followed the pseudo-second-order kinetic mode. Then, an ultrasound-assisted magnetic solid-phase extraction with Fe3O4/N-G as the magnetic adsorbent has been developed for the determination of four compounds including triclosan, chloroxylenol, hexachlorobenzene and 2,2',4,4',5,5'-hexachlorobiphenyl in environmental water samples, in combination with gas chromatography coupled to tandem mass spectrometry. Several factors related to extraction efficiencies, such as the amount of adsorbent, extraction time, sample pH and desorption conditions were investigated. The proposed preparation procedure was as follows: 6.0 mg of Fe3O4/N-G was dispersed into 100 mL of water sample under ultrasound. After 15 s, the Fe3O4/N-G carrying four compounds was separated from the water sample by an external magnetic field. Then, the targets were eluted from Fe3O4/N-G with 3 mL of ethanol and 2 mL of dichloromethane, sequentially. Finally, the eluent was dried under a mild stream of nitrogen and reconstituted with methanol and dichloromethane (1∶1, V/V) for the subsequent GC-MS/MS analysis. Under the optimized condition, an excellent linearity was observed in the range of 0.1-10 ng/L for the four compounds, with the correlation coefficients ranging from 0.9983 to 0.9999. The limits of detections (S/N=3) ranged from 0.05 to 0.6 ng/L and the limits of quantity (S/N=10) ranged from 0.2 to 2.4 ng/L. The mean recoveries at three spiked levels ranged from 68.2% to 99.6%. The relative standard deviations (RSDs) of intraday and interday were in the range of 3.3%-6.9% and 3.4%-9.4% (n=6), respectively. The proposed method was demonstrated to be simple and feasible for the trace analysis of antimicrobial agents and organochlorine contaminants in environmental water samples.
2017, 45(5): 770-776
doi: 10.11895/j.issn.0253-3820.160893
Abstract:
Reuse of waste oil in cooking has been the social concern for long time, but until now there is no reliable method to identify the gutter oil. In this work, based on the generation of long-chain aliphatic aldehydes in the refinement of gutter oil, gutter oil and adulterate cooking oil were identified by determining hexanal, heptanal, octanal, nonanal and decanal in oil sample with high perfomance liquid chromatography (HPLC) method using O-(3-(9H-carbazol-9-yl)propyl)hydroxylamine as the fluorescent derivative reagent. At first, 10 μL of oil sample was dissolved in 200 μL of isopropanol, then reacted with O-(3-(9H-carbazol-9-yl)propyl)hydroxylamine to form the stable derivatives, extracted with acetonitrile and injected into HPLC for analysis. The derivatives were separated on a C18 column within 15 min with ACN-H2O (90∶10, V/V) as mobile phase. The fluorescence detector was set at λex/λem=292 nm/348 nm. The linear range of 5 kinds of long-chain aliphatic aldehydes was 0.01-1.00 μmol/L with limit of detection (LOD, S/N=3) of 0.05-0.10 nmol/L, and the spiked recoveries were 95.6%-101.4%. The results showed that the edible oils obtained from supermarket almost had no hexanal, heptanal, octanal, nonanal, decanal, but these aldehydes increased significantly in gutter oil. Thus the 5 kinds of long-chain aldehydes could be used as the indictor of gutter oil. Taking the advantage of good specificity, higher sensitivity, good accuracy and simplicity, the method was suitable for the rapid identification of gutter oil.
Reuse of waste oil in cooking has been the social concern for long time, but until now there is no reliable method to identify the gutter oil. In this work, based on the generation of long-chain aliphatic aldehydes in the refinement of gutter oil, gutter oil and adulterate cooking oil were identified by determining hexanal, heptanal, octanal, nonanal and decanal in oil sample with high perfomance liquid chromatography (HPLC) method using O-(3-(9H-carbazol-9-yl)propyl)hydroxylamine as the fluorescent derivative reagent. At first, 10 μL of oil sample was dissolved in 200 μL of isopropanol, then reacted with O-(3-(9H-carbazol-9-yl)propyl)hydroxylamine to form the stable derivatives, extracted with acetonitrile and injected into HPLC for analysis. The derivatives were separated on a C18 column within 15 min with ACN-H2O (90∶10, V/V) as mobile phase. The fluorescence detector was set at λex/λem=292 nm/348 nm. The linear range of 5 kinds of long-chain aliphatic aldehydes was 0.01-1.00 μmol/L with limit of detection (LOD, S/N=3) of 0.05-0.10 nmol/L, and the spiked recoveries were 95.6%-101.4%. The results showed that the edible oils obtained from supermarket almost had no hexanal, heptanal, octanal, nonanal, decanal, but these aldehydes increased significantly in gutter oil. Thus the 5 kinds of long-chain aldehydes could be used as the indictor of gutter oil. Taking the advantage of good specificity, higher sensitivity, good accuracy and simplicity, the method was suitable for the rapid identification of gutter oil.
2017, 45(5): 777-783
doi: 10.11895/j.issn.0253-3820.160866
Abstract:
A method based on QuEChERS coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of seven kinds of fluorescent white agent residues in mushroom. After mixing with 10 mL of water, the sample was extracted with acidified acetonitrile, cleaned up by C18, primary secondary amine (PSA) and MgSO4. The separation of seven kinds of fluorescent white agents was performed on a C18 column with a gradient elution of acetonitrile and 0.1% acidified water as mobile phase. The target compounds were detected by electrospray ionization mass spectrometry in positive ion mode with multi reaction monitoring (MRM). Under the optimum conditions, the method had good linear relationship in the determination of the seven kinds of fluorescent white agents in a certain concentration range, with correlation coefficients greater than 0.991. Moreover, the limits of detection (S/N=3) were 0.05-0.4 μg/kg, the limits of quantitation (S/N=10) were 0.2-1.3 μg/kg, and the average recoveries for seven kinds of fluorescent white agent residues in msushroom were 70.1%-109.2%. In comparison with previous methods, the new procedure has characteristics of simple sample preparation and higher sensitivity.
A method based on QuEChERS coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of seven kinds of fluorescent white agent residues in mushroom. After mixing with 10 mL of water, the sample was extracted with acidified acetonitrile, cleaned up by C18, primary secondary amine (PSA) and MgSO4. The separation of seven kinds of fluorescent white agents was performed on a C18 column with a gradient elution of acetonitrile and 0.1% acidified water as mobile phase. The target compounds were detected by electrospray ionization mass spectrometry in positive ion mode with multi reaction monitoring (MRM). Under the optimum conditions, the method had good linear relationship in the determination of the seven kinds of fluorescent white agents in a certain concentration range, with correlation coefficients greater than 0.991. Moreover, the limits of detection (S/N=3) were 0.05-0.4 μg/kg, the limits of quantitation (S/N=10) were 0.2-1.3 μg/kg, and the average recoveries for seven kinds of fluorescent white agent residues in msushroom were 70.1%-109.2%. In comparison with previous methods, the new procedure has characteristics of simple sample preparation and higher sensitivity.
