最新刊期
卷 36 ， 期 6 ， 2017
- 摘要：Multivariate statistical analysis methods,principal component analysis and partial least square discrimination analysis,were applied in this study for the data mining of cigarette smoke exposure metabolomics on plasma,urine and lung samples,in order to characterize the holistic influences of cigarette smoke exposure,and screen potential biomarkers.The screened biomarkers obtained from the metabolic profiling analysis on plasma,urine and lung were integrated and reduced by neurofuzzy logic.The predictability of the established model with this focused biomarkers were evaluated by artificial neural networks.Key biomarkers were closely related to different smoke exposure time(7,14,30 days),and different kinds of cigarette smoke exposure on the endogenous metabolites in rats were found in this study,and the damage mechanism of cigarette smoke exposure on rat′s organism was discussed.关键词：artificial neural networks;neurofuzzy logic;metabolomics;cigarette smoke exposure;key biomarkers
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发布时间： - 摘要：A microwave digestion combined with inductively coupled plasma mass spectrometric(ICP-MS) method was established for the simultaneous determination of 24 elements(Li,Be,B,Al,V,Cu,Mn,Zn,Cr,Ni,As,Sr,Zr,Se,Mo,Ag,Cd,Sn,Sb,Te,Ba,Hg,Tl,Pb) in food packaging paper materials and 3 kinds of food simulants(water,4% acetic acid,10% ethanol).The migration behaviors of these elements were investigated.The samples were digested by microwave and then detected by ICP-MS,and the food simulants were detected without microwave digestion. Under the optimized experimental conditions,24 elements showed good linear relationships in the range of 0-1000μg/L, with the method detection limits(MLOD) of 0.0003-0.465mg/kg.The recoveries of these analytes at spiked levels of 1.0-1000mg/kg were in the range of 90.5%-125.3% with relative standard deviations of 1.2%-6.8%.This method is simple, sensitive and accurate, and is suitable for the research on determination and migration behavior of elements in food packaging paper materials, which could provide a scientific basis for the quality supervision of food paper packaging materials.关键词：elements;food packaging materials;microwave digestion;food simulants;ICP-MS
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发布时间： - 摘要：A novel method based on the monolith solid-phase microextraction(SPME) coupled with high performance liquid chromatography was developed for the determination of trace benzimidazoles in foods. The preparation of poly(vinylphenylboronic acid-co-ethylene glycol dimethacrylate) microextraction monolith based on ternary porogen was synthesized by in situ technique.The characteristics of the monolith were investigated by thermogravimetric,infrared spectroscopy and scanning electron microscopy analysis.Effects of extraction solvents，extraction velocity,purification volume,desorption solvents,desorption velocity and desorption volume on extraction amount were investigated.Under the optimal conditions,the enrichment factors of SPME monolith for benzimidazoles were in the range of 1607-3015.The calibration curves of benzimidazoles showed good linear relationships in the range of 0.100-100μg/L,with detection limits of 21-33ng/L and relative standard deviations(RSD) no more than 7.4%.The proposed method was successfully applied in the determination of benzimidazoles in fish,duck,duck blood and duck liver samples，with recoveries of 75.0%-118% and RSDs of 1.6%-8.7%.The proposed method based on SPME monolith was sensitive and accurate in the trace determination of benzimidazoles in complex samples.关键词：monolith;solid-phase microextraction;high performance liquid chromatography(HPLC);benzimidazoles;food
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发布时间： - 摘要：Bohai heavy oil was separated into asphaltene,resin and remaining fraction by precipitation and silica gel chromatography.Molecular compositions of Bohai heavy oil and its fractions were characterized by Fourier transform ion cyclotron resonance(FT- ICR) mass spectrometry(MS) with negative ion electrospray ionization(ESI).The results showed that less polar molecules containing N1,N1O1,O1,O2 compounds with low double bonds equivalent(DBE) in remaining fraction could be ionized by ESI.The heteroatom classes and the distribution patterns of N1,O1,O2 class species in the resin fraction and crude oil are similar, and the heteroatoms classes contain N1,N1O1,N1O2,N2,N2O2S1,O1,O2 classes. The asphaltene fraction contains acidic compounds with high degree of condensation and high order heteroatom,such as N1O3,S1O3,N2O1 and O3 species, which have high interfacial activity.They could promote the reduction of interfacial tension and the strength of interfacial film through adsorbing at oil-water interface.N1O1,N1O2,N1O3 class species could be the oxidation degraded products from N1 compounds, and the N2O1 class species could be generated by oxidizing degradation of N2 compounds. And the polarity of degraded products increases obviously with the increase of oxidizing degraded degree.关键词：heavy oil;asphaltene;resin;remaining fraction;Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS);molecular composition
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发布时间： - 摘要：An ultra-performance liquid chromatography-tandem mass spectrometric(UPLC-MS/MS) method was developed for the simultaneous determination of indole-3-acetic acid(IAA) and its three oxidative products, indole-3-methanol(ICI),indole-3-carboxaldehyde(ICA) and indole-3-carboxylic acid(IFA) in corn(Zea mays L.) leaves. The results showed that the detection limits for the four compounds were in the range of 0.002-1.63μg/kg, and the quantitation limits were 0.007-5.43μg/kg. The recoveries ranged from 89.5% to 95.3% with RSDs of 2.3%-5.1%. The method was applied in the determination of the contents of IAA,ICI,ICA and IFA in corn leaves with their results of (196.25±7.10),(26.21±2.13),(18.65±2.02),(13.62±2.06)μg/kg, respectively. Meanwhile, the proposed method was also successfully applied in the analysis of wheat(Triticum aestivum L.),pea(Pisum sativum L.) and bristly starbur(Acanthospermum hispidum DC.),which indicated that the method had a good generality.关键词：corn-leaves;indole-3-acetic-acid;indole-3-methanol;indole-3-carboxaldehyde;indole-3-carboxylic acid;ultra-performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)
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发布时间： - 摘要：An analytical method based on QuEChERS with modified multiwalled carbon nanotubes(MWNTs) as adsorbent was developed.The determination of 6 mycotoxins and 3-pesticides-residues,including 2,4-D,methomyl,chlorpyrifos,AFG2,AFG1,AFB2,AFB1,OTA and ZEN in xinhui dried orange peel was carried out by liquid chromatography-tandem mass spectrometry(LC-MS/MS).The factors affecting the extraction，purification and detection efficiency were optimized，and the optimal conditions were as the following：the samples were extracted with acetonitrile-water(80∶20) mixed solution，and purified by QuEChERS method with modified MWNTs as adsorbent.The separation was performed on a Shimadzu C18(150 mm×2.1 mm×3.5 μm) column,then determined by LC-MS/MS under multiple reaction monitoring(MRM) mode and quantified by external standard method with the matrix matched standards solution.Under the optimized conditions,the calibration curves of 9 compounds were linear in the respective concentration ranges with correlation coefficients of 0.983 8-0.998 2.The detection limits(S/N=3) were in the range of 0.18-10 μg/kg.The recoveries at low,medium and high spiked levels ranged from 72.4% to 106%,with relative standard deviations of 2.2%-7.4%.With the advantages of accuracy,high sensitivity，easy operation and rapidness,the method was suitable for the simultaneous determination of mycotoxins and pesticide in xinhui dried orange peel,and was applied in the rapid screening of toxic and harmful substances in foods with satisfactory results.关键词：QuEChERS;modified multiwalled carbon nanotubes;liquid chromatography-tandem mass spectrometry(HPLC-MS/MS);mycotoxins;pesticide residue;xinhui dried orange peel
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发布时间： - 摘要：A method was developed for the separation and determination of 7 chiral polychlorinated biphenyls(PCBs) congeners(PCB 45,PCB 91,PCB 95,PCB 132,PCB 136,PCB 149 and PCB 174) in fish samples.The target chemicals were extracted by accelerated solvent extraction，cleaned up by gel permeation chromatography,acidified with silica gel column and multi-layer silica gel column，and were further fractioned with alkaline alumina columns．The chiral PCBs were identified and quantified by gas chromatography-mass spectrometry with electron impact ion source(GC-EI/MS).Five commercially available chiral capillary gas chromatography columns(BateDex-325,CP-Chirasil,BGB-172SE,Chirasil-Dex and Cyclosil-B) were evaluated for their ability to separate enantiomers of 7 chiral PCBs.Among the columns studied,Cyclosil-B capillary column obtained the best results,providing the simultaneous separation of 7 chiral PCBs with the enantioselective resolution of 0.8-2.3.The calibration curves of these seven chiral PCBs showed good linearities in the range of 10-200 μg?L-1 with correlation coefficients 0.998-1.000.The limits of detection(LOD,S/N=3) were all below 5.0 ng?g-1.The method was applied in the determination of the analytes in spiked fish samples,with recoveries of of 89.2%-114% and relative standard deviations(RSDs,n=7) of 0.3%- 2.1%，suggesting the high degree of accuracy and efficiency of the established method．The developed method was applied in fish samples which collected from a reservoir surrounded by several e-waste recycling workshops in Guangdong.PCBs and enantiomer franctions(EFs) of chiral PCBs(PCB 45,PCB 91,PCB 95,PCB132,PCB 136,PCB 149 and PCB 174) were analyzed in three kinds of fish samples.The concentrations of chiral PCBs ranged from 386.7 ng?g-1 to 602.8 ng?g-1in fish smaples.The EF values of chiral PCBs(PCB 45,PCB 91,PCB 95,PCB 132,PCB 136 and PCB 174) were significantly different with those in standard solution,which meaned that these chiral PCBs had enantioselective enrichment and metabolism in fish tissue.In addition,the EF values of chiral PCBs of PCB 45,PCB 91,PCB 95,PCB 132 and PCB 136 in three kinds of fish tissue were similar,with an exception of PCB 174．The declined EFs of PCB 174 in Cirrhinus moliorella and Cirrhinus moliorella were rebounded in Ophicephalus argu.This result may suggest that the Ophicephalus argu and Cirrhinus moliorella or Carassius auratus preferred to biotransform different enantiomers of PCB congeners.关键词：chiral;polychlorinated biphenyl;gas chromatography-mass spectrometry(GC-MS);fish sample;enantiomer separation
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发布时间： - 摘要：Magnetic molecularly imprinted polymers(MMIPs) with specific recognition ability were successfully synthesized by using butachlor as template molecule and acrylamide(AM) as functional monomer.MMIPs were characterized by transmission electron microscopy(TEM),infrared spectroscopy(FT-IR) and vibrating sample magnetometry(VSM).The results showed that molecularly imprinted layer was successfully wrapped on the surface of Fe3O4.MMIPs showed a specific recognition for five chloroacetamide herbicides.The developed magnetic molecular imprinted solid phase extraction coupled with gas chromatography(MMISPE/GC) method exhibited a good recovery(85.0%-99.5%),a good precision(RSD:2.8%-5.0%，n=5),a good linearity(0.1-500 μg?L-1) and a low limit of detection(0.02-0.05 μg?L-1) under the optimized conditions.The introduced MMISPE/GC method was successfully used to analyze five chloroacetamide herbicides in environmental water samples.关键词：chloroacetamide herbicides;magnetic molecularly imprinted polymers;magnetic solid phase extraction;adsorption performance;gas chromatography
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发布时间： - 摘要：A method was established for the determination of six arsenic species including arsenite(As(Ⅲ)),arsenate(As(V)),monomethylarsine (MMA),dimethyarsine (DMA),arsenobetaine(AsB) and arsenocholine(AsC),in animal derived traditional Chinese medicines by liquid chromatography coupled with inductively coupled plasma mass spectrometry(LC-ICP-MS) assisted by microwave acid extration.After microwave extraction with 1% HNO3 solution within 10 min and centrifugation,the sample was purified with solid phase extraction SPE C18 and 0.45 μm hybrid filter membrane,and then eluted with 25 mmol/L NH4H2PO4 (pH 6.7) –ethanol(99∶1,by volume) as mobile phase by isocratic elution.The arsenic species could reach a baseline separation within 10 min.The results showed that the linear ranges for six arsenic species were in the range of 1.0-100.0 μg/L with correlative coefficients of 0.999 5-0.999 7.The limits of detection (LOD) for six anions were in the range of 0.24-1.0 μg/kg with relative standard derivations(RSD) of 0.96%-2.0%.The method was used in the determination of arsenic speciation in six samples involved pberetima,leech,cuttlebon,ootheca mantidis,shell of abalone and ventriculi galli mucosa.The spiked recoveries were between 94.2% and 103.8% and the extraction efficiencies were in the range of 95.5%-102.8%,which are better than those obtained by heat extraction.With the advantages of quickness,accuracy and good reproducibility,the method was suitable for the arsenic species detection and quality monitoring of animal derived traditional Chinese medicine and similar samples.关键词：microwave acid extration;liquid chromatography coupled with inductively coupled plasma mass spectrometry (LC-ICP-MS);animal derived traditional Chinese medicine;arsenic species analysis
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发布时间： - 摘要：The principal component analysis method combined with genetic algorithm and neural network was used to establish the sensory evaluation model based on the endogenous aromatic components of tobacco.GC-MS method was used to qualitatively and quantitatively analyze the endogenous aromatic components of tobacco essential oil obtained by supercritical extraction and molecular distillation.Initially,principal component analysis(PCA) was used to analyse endogenous aromatic components.Scores of the five extracted principal components and sensory evaluation were then used as the input and output variables,respectively.Back-propagation(BP) neural network was used to establish the prediction model.Genetic algorithm(GA) was further applied to optimize the neural network weights and thresholds.The experimental results showed that the performance of GA-BP model was better than that of BP.The correlation coefficient between the predicted value by the GA-BP model and the experimental value was 0.96,and the root mean square error of prediction(RMSEP) was 1.81.The GA-BP model showed better fitting ability and prediction ability.The model could effectively predict the sensory quality of the essential oil.关键词：principal component analysis;endogenous aromatic components;chemometrics;Genetic algorithm;BP neural network;sensory evaluation
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发布时间： - 摘要：An ultra performance liquid chromatography-tandem mass spectrometric(UPLC-MS/MS) method was established for the determination of 14 quinolones in hotpot.Samples were extracted with acidified acetonitrile,defated with n hexane,separated on a C18 solid phase extraction(SPE) column,and analyzed by LC-ESI-MS/MS under the positive mode with multiple reaction monitoring(MRM).The method showed good linearities for 14 quinolones over the range of 7.5-100 μg/L with correlation coefficients(r) more than 0.990.The detection limits of 14 quinolones were 0.5 μg/kg,and the quantitation limits were 1.5 μg/kg.The recoveries of all analytes in hotpot ranged from 75.4% to 110.0%with relative standard deviations(RSD,n=6)of 1.3%-10.1%.The method has the advantages of simplicity,rapidness,good purifying effect and sensitivity,and is suitable for the simultaneous determination of quinolones in hotpot.关键词：SPE;ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS);quinolones;hotpot
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发布时间： - 摘要：A new method for the determination of vancomycin and norvancomycin residues in shrimps by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) was established.Samples were extracted with 0.1% formic acid-acetonitrile solution,defatted with n hexane saturated with acetonitrile and purified with PCX and Florisil solid phase extraction column.The separation of two targets was carried out on a CAPCELL PAK MG-C18 column by gradient elution with 0.1% formic acid-acetonitrile as mobile phase．The identification of two analytes was performed in multi-reaction monitoring(MRM),and the quantification was carried out by the internal standard method.Dedichloro vancomycin was used as an internal standard.The calibration curves showed good linearities in the range of 2-250 ng/mL with correlation coefficients(r2) greater than 0.99.The detection limits(LOD) of this method were both 2.0 μg/kg,and the limits of quantitation(LOQ) were 5.0 μg/kg.The recoveries of the target compounds at spiked levels of 5,25,50 μg/kg were in the range of 87.2%-102%,with relative standard deviations(RSDs) of 1.3%-8.7%.The results indicated that this method had high sensitivity,accuracy and good reproducibility.It was suitable for the simultaneous determination of ancomycin and norvancomycin residues in shrimps.关键词：vancomycin;norvancomycin;dedichloro vancomycin;shrimps;high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)
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发布时间： - 摘要：A high performance liquid chromatographic method with pre-column derivatization was developed for the determination of 2-aminobutane in vegetables and fruits.The sample was distilled with kjeldahl apparatus.The distillate was neutralized with NaOH solution before derivatization with 9-fluorenylemethyl chloroformate(FMOC) as derivatization agent under alkaline condition.The sample was separated on a C18 analytical column and detected by HPLC with a UV detector at a wavelength of 265 nm.Systematic investigation was carried out on the dependence of the derivatization conditions such as concentration of derivatization,pH value of borate buffer solution,reaction temperature and time etc.The optimized conditions were as follows:concentration of derivatization:0.50 g/L,pH value of borate buffer:8.0,reaction temperature:room temperature,and reaction time:10 min.Under the optimal conditions,a linear relationship was achieved between the peak area and the concentration of 2-aminobutane in the range of 0.001-1.000 mg/L，with a correlation coefficient of 0.999 8.The recoveries at three spiked levels were in the range of 82.4%-95.2% with relative standard deviations (RSDs) of 1.3%-6.8%.The limit of detection(LOD) was 0.1 μg/kg,and the limit of quantitation (LOQ) was 0.5 μg/kg.With the advantages of rapidness,simplicity,safety,high sensitivity and reproducibility,this method is suitble for the determination of 2-aminobutane in vegetables and fruits.关键词：pre-column derivatization;high performance liquid chromatography (HPLC);kjeldahl apparatus;2-aminobutane;vegetables and fruits
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发布时间： - 摘要：A QuEChERS/HPLC-MS/MS method was developed for the simultaneous determination of imidacloprid,triadimefon,acetochlor and metolachlor residue in corn flour.The residues were extracted from samples with acetonitrile and cleaned up by dispersive method using PSA and GCB，then detected by high liquid chromatography-mass spectrometry(HPLC-MS/MS) under multiple reaction monitoring mode,and quantified by the matrix-matched standard solution.The results showed the method had a good linearity(r2≥0.998) in the range of 0.005-1.000 mg/L.Average recoveries at three spiked levels of 0.05-1.00 mg/kg were in the range of 74.9%-98.4%with relative standard deviations(n=5) of 1.6%-5.3%.The limits of detection(LOD) for 4 pesticides were in the range of 0.001-0.26 μg/kg，and limits of quantitation(LOQ) were in the range of 0.004-0.867 μg/kg.With the advantages of rapidness，simplicity，high sensitivity and good reproducibility,the method is suitable for the determination of target pesticides in corn flour.关键词：QuEChERS;imidacloprid;triadimefon;acetochlor;metolachlor;HPLC-MS/MS
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发布时间： - 摘要：Lignin was extracted from ecological invasive plant water hyacinth by alkali extraction.The extracted product was characterized by FT-IR and SEM methods.The effects of some factors such as pH value，adsorption time,initial concentration on the adsorption capacity of water hyacinth lignin for aniline were evaluated.When the concentration of NaOH solution was 0.1 mol/L,the extraction time was 4 h,temperature was 100 ℃,and the solid-liquid ratio was 1∶20,the yield of water hyacinth lignin was the maximum of 6.81%.The infrared spectrum showed the stretching vibrations of the C‖C bonds in the aromatic skeleton at 1 456-1 656 cm-1.The results of the infrared spectrum indicated that the obtained product was lignin.The result of SEM showed that water hyacinth lignin composed of a large number of small amorphous particles,and there were many micro pores on the surface of lignin particles,which would be benefit to increase the adsorption capacity.The maximum adsorption capacity reached up to 12.2 mg/g at pH 6.0 with an initial concentration of aniline of 150 mg/L,an adsorbent dosage of 5 mg and an adsorption time of 120 min at room temperature.The adsorption data fited well with the Pseudo second order kinetics model and the Langmuir isotherm model.The adsorption of aniline by water hyacinth lignin was mainly assigned to chemical adsorption of monolayer and favorable adsorption.Under the same adsorption conditions,the adsorption capacities of water hyacinth lignin for aniline in a lake water samples were similar to that in the simulated water samples.Water hyacinth lignin could be used as enrichment and seperation material for sample pretreatment and removing pollutant in wastewater.关键词：water hyacinth;lignin;alkali extraction;aniline;adsorption
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发布时间： - 摘要：The highly solubile and photocatalytic carbon quantum dots(CDs) were prepared by a one-pot hydrothermal method.The CDs could oxidize the typical substrate of 3,3-,5,5-tetramethylbenzidine(TMB) of the horseradish peroxidase(HRP) under visible light(λ≥400 nm) irradiation causing the color signal.In this assay,the interaction between copper ion and CDs will suppress the oxidase mimicking activity of CDs.Upon introduction of target pyrophosphate ions(ppi) into the detection system,the Cu2+-ppi complexes were forming on the basis of the coordination reaction between copper ion and inorganic pyrophosphate ions,thus the oxidase mimicking activity of released CDs was recovered.Based on this characteristic,a colorimetric sensor for the ppi detection was designed.Under the optimal conditions,the obtained colorimetric signal showed a linear response to ppi within a dynamic range of 1.0×10-6-5.0×10-3 mol/L with a detection limit(LOD) of 2.5×10-7 mol/L.The method was applied in the determination of ppi in human plasma samples,with recoveries of 97.4%-104.8%.The results showed that the colorimetric sensor could be used to detect ppi in human plasma samples.关键词：carbon quantum dots;enzyme mimetics;colorimetry;pyrophosphate ion
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发布时间： - 摘要：A rapid analytical method using on-line immunoaffinity column clean-up and high performance liquid chromatography(HPLC) was developed for the determination of aflatoxins(B1，B2，G1，G2) in feed samples.The samples were extracted with acetonitrile-water solution(80∶20,by volumn).The extraction solution was diluted by 10 times using 3 g/L triton X-100 water solution,then injected into the RIDA-CREST on-line immunoaffinity column clean-up system,and washed out with methanol-water(45∶55,by volume) as mobile phase at a flow rate of 1.0 mL/min.Aflatoxins were analyzed by HPLC/FLD with post-column photochemical derivatizaton.The detection limits of AFB1,AFB2,AFG1 and AFG2 were 0.08,0.05,0.18,0.08 μg/kg,respectively.The linear ranges for AFB1,AFB2,AFG1 and AFG2 were 1-100,0.24-24,0.56-56,0.24-24 μg/kg,with their correlation coefficients(r2) of 0.999 4,0.999 7,0.999 8 and 0.999 8,respectively.The recoveries for four kinds of feed samples spiked with aflatoxins were in the range of 72.6%-103%,with relative standard deviations of 2.5%-4.9%.Each immunoaffinity colomn could be used for 60 samples cleanup,and the total running time for each HPLC analysis is 15 min,thus 70-80 samples could be detected per day.This method could satisfy the demands for rapid and accurate analysis of aflatoxin in feed.关键词：feed;aflatoxins;on-line immunoaffinity column clean-up;high performance liquid chromatography(HPLC)
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发布时间： - 摘要：A novel method of flow injection chemiluminescence for the determination of rifapentine was proposed based on the phenomenon that the chemiluminescence intensity of the luminol-K3Fe(CN)6 system could be enhanced by rifapentine in alkaline medium,combined with flow injection analysis technique.Under the optimal experimental conditions,the linear range of rifapentine’s detection concentration was 0.008-0.88 mg/L,the detection limit(3σ) was 1.2×10-3 mg/L,and the relative standard deviation(RSD,n=11) was 1.9% for rifapentine at 6.0×10-2 mg/L.The method was applied in the determination of rifapentine in both capsules and plasma with satisfactory results.关键词：flow injection;chemiluminescence;luminol;potassium ferricyanide;rifapentine
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发布时间： - 摘要：A liquid chromatography-tandem mass spectrometric(HPLC-MS/MS)method for the determination of pantothenic acid in urine was developed and validated.After centrifugation and dilution,the sample was separated on an ACPUITY UPLC HSS T3(2.1 mm×100 mm,1.8 μm) column produced by the Waters corporation,and ionized in electro spray positive ion mode,then detected using multi reaction monitoring mode.The calibration curve has a good linear range with a correlation coefficient(r) of 0.999 3.The limit of detection is 0.46 ng/mL,the recoveries are in the range of 87.9%-95.3%,and the RSDs are in the range of 2.5%-13.0%.The method has the advantages of high sensitivity and short analysis time,and could be used to analyze pantothenic acid in human urine.关键词：liquid chromatography tandem mass spectrometry;urine;pantothenic acid;biomonitoring
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发布时间： -
Separation and Determination of Three Diasteromers in Neuroprotectant 3β，5α，6β-Androstriol Bulk Drug
摘要：A GC method for the separation and determination of three diasteromers in neuroprotectant 3β，5α，6β-androstriol(YC-6) bulk drug was developed.The separation conditions such as column type，injection port temperature，column temperature and sample concentrate were optimized，and method validation was developed.The results showed that the method had a good specificity（resolution（R） ≥1.5） and a good precision（RSD≤2.0%，n=6）.The calibration curve showed a good linearity over the concentration range of 6.0-30.0 μg/mL for YC-6.The response factors of three diasteromers were 1.59，1.32 and 1.41，respectively，and their contents were detected by principal component self-comparison with calibration factor and internal standard method.The method was simple，sensitive and valid，and was successfully applied in the analysis of diasteromers in neuroprotectant 3β，5α，6β-androstriol bulk drug.关键词：3β,5α,6β-androstriol;diasteromers;content determination;gas chromatography（GC）- 759
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发布时间： - 摘要：Pathogen adhesion to host tissue is a prerequisite for a majority of infectious diseases.A common way for accomplishing adhesion is specific recognition of bacterium cellular lectins towards glycan on the surface of the host cells.Therefore,research on pathogenic bacteria-glycan interactions is beneficial to further understand the pathogenic mechanism of infectious diseases.Meanwhile,it could provide new strategies for specific detection on pathogenic bacteria and treatment of infectious diseases,and the mechanisms related with adhesion of pathogenic bacteria,carbohydrate-lectin interactions and multivalent interactions were summed up.The analysis technologies of pathogenic bacteria-glycan interactions were introduced,especially,the latest development and research of surface plasmon resonance,quartz crystal microbalances,fluorescence spectrum and electrochemical impedance spectroscopy were summarized.Special attention was paid to the combination of those detecting technologies and microfluidic chip platforms.In view of the serious problems of antibiotics resistance and poor specificity of pathogenic bacteria detection,the applications of bacterial isolation,enrichment,detection,identification,biofilm inhibition and the screening of antimicrobial agents were reviewed.Finally,the future development for basic research and application of pathogenic bacteria-glycan interactions were prospected.关键词：carbohydrate-lectin interactions;multivalent interactions;bacterial adhesion;bacterial detection;review
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发布时间： - 摘要：Mycotoxins are widely present in food and animal feed.They are harmful to animal and human health through the food chain,and will reduce the nutritional value of feed and cause serious food safety problem.It is very necessary to develop efficient sample pretreatments and sensitive analytical methods for rapid analysis of these targets in complex matrix.In this paper,some pretreatment methods including solid phase microextraction,liquid phase microextraction,magnetic separation,immuno affinity chromatography etc.are introduced.Meanwhile,the applications and developments of analytical methods for mycotoxins,such as liquid chromatography-mass spectrometry,enzyme linked immune sorbent assay and biosensors etc.,are also reviewed.关键词：food samples;mycotoxins;sample pretreatment;analytical method;review
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发布时间：
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