最新刊期
      卷 37 ， 期 5 ， 2018
      • Vol. 37, Issue 5, Pages: 517-524(2018)
        摘要：The 3D-QSAR relationships of a series of quinolone carboxylic acid derivatives were studied by Topomer CoMFA technique based on R group search.The interaction validation coefficient（q2）,the non cross correlation coefficient（r2） and the external validation coefficiont（r2pred） were 0790,0890 and 0878，respectively.The results showed that the model had a good stability and a prediction ability.Topomer search was used to virtually screen lead like compounds in the ZINC molecular database.As a result,6 Ra groups and 3 Rb groups with higher contribution values were selected.12 new quinolone carboxylic acid compounds with higher predicted activity were designed.By using molecular docking,the action mechanism of drug and acceptor was studied,and the results showed that the drug functioned obviously with ASP 30,ASP 29 and ASN 25 sites of protease.The QSAR study could provide a theoretical reference for the synthesis of new drugs.  
        关键词：three dimensional quantitative structure-activity relationship（3D-QSAR）;quinolone carboxylic acid derivatives;Topomer CoMFA;molecular design;molecular docking   
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      • Vol. 37, Issue 5, Pages: 525-531(2018)
        摘要：In this work,the interactions between transthyretin(TTR) and one brominated flame retardant(BFR) and two hydroxylated BFRs,namely 3,5,3′,5′ tetrabromo 4,4′ dihydroxydiphenylsulfon(TBS),4 hydroxy 2,2′,3,4′,5,5′,6 heptabromodiphenyl ether (4 OH-BDE-187) and 6 hydroxy 2,2′,3,4,4′,5,5′ heptabromodiphenyl ether(6 OH-BDE-180),were studied by native electrospray ionization mass spectrometry(Native ESI-MS) and molecular docking simulation(MDS).ESI-MS results indicated that,in a 37 ℃ physiological pH value buffer,TBS,4 OH-BDE-187 and 6 OH-BDE-180 could stably combine with TTR by the stoichiometric ratios of 1∶1,1∶1 and 2∶1 to form TTR complexes,respectively.Molecular docking simulation was performed to generate the models of the protein complexes formed by these three ligands binding toTTR.MDS results demonstrated that the binding sites of TTR with these three ligands may be in the pocket around ASP 74 residue.The study is helpful for understanding the toxicology mechanisms of brominated flame retardants and their hydroxylated metabolites.  
        关键词：native electrospray ionization mass spectrometry(native ESI-MS);high performance liquid chromatography(HPLC);transthyretin;brominated flame retardant;protein complexes   
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      • Vol. 37, Issue 5, Pages: 532-538(2018)
        摘要：The volatile oils in fresh red pine needles from Xiao Hinggan Mountains,were extracted by steam distillation,and then analyzed by comprehensive two dimensional gas chromatography-time of flight mass spectrometry（GC×GC-TOF MS）.The chromatographic separation conditions were optimized,and the best conditions were confirmed to be a modulation period of 6 s,a second dimensional column length of 3 m,and a temperature of 20 ℃ for the second dimensional column higher than that for the first dimensional column all the time.Under the optimal conditions,217 kinds of compounds were identified based the NIST library,and the quantitative calculation was carried out by area normalization method.Total of the compounds identified was four times more than that identified by one dimensional gas chromatography（1DGC）.124 terpenoids,including 48 monoterpenoids,64 sesquipenoids and 12 diterpenoids were identified from the volatile oils of fresh red pine needles,accounting for about 69% of all.And 33 ester compounds accounting for about 12% of all,6 organic acids,15 alcoholic compounds,15 aldehyde compounds,11 ketone compounds and 13 other compounds were also identified.Compaired with the one dimensional gas chromatography,two dimensional gas chromatography- time of flight mass spectrometry possesses higher resolution and sensitivity,and it shows a unique superiority in the analysis of complex natural products.  
        关键词：pine needles;volatile oils;comprehensive two dimensional gas chromatography/time of flight mass spectrometry（GC×GC/TOF MS）;analysis of chemical composition   
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      • Vol. 37, Issue 5, Pages: 539-546(2018)
        摘要：The changes of measurement environment and spectral signals of spectroscopy instruments could lead to big errors in the transferring process of the NIR（near infrared） spectra model to slave instruments.The influences of baseline drift and light scattering on NIR spectra were eliminated by standard normal variate transformation（SNV） plus derivative pretreatment in this paper.And then the wavelengths in which spectral signals are consistent and the spectral differences among samples are great were selected by screening wavelengths based on spectrum ratio analysis（SWSRA） among instruments.The partial least squares regression（PLS） models for predicting quality to be measured were built on the basis of the selected wavelength variables.Two data sets were utilized to validate the SWSRA method,in which one set was consisted of 72 Scutellaria baicalensis samples whose NIR spectra were measured on two types of NIR spectroscopy instruments,another one was composed of 80 corn samples whose contents of moisture,protein and oils,and NIR spectra measured on three NIR instruments were available online.The results showed that the average errors of slave instruments for samples predicted by SWSRA models built on master instrument were all below 43%.Root mean square error of prediction（RMSEP） of the method was much lower than that of the full-wavelength PLS model transferred to slaves,which was equivalent or superior to those of the other model transfer methods reported in literatures.With the advantages of few parameters,stability and simplicity,the SWSRA method could keep a good prediction performance during the transmission of spectral signals between the master and salve instruments.Similar near-infrared instruments could share the SWSRA models without standards.  
        关键词：spectrum ratio analysis;wavelength selection;model transfer without standards;near infrared（NIR） spectroscopy   
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      • Vol. 37, Issue 5, Pages: 547-555(2018)
        摘要：A method was developed for the simultaneous determination of 16 benzimidazoles and 13 nitroimidazoles residues in fish and fishery products using ultrahigh performance liquid chromatography quadrupole/electrostatic field orbitrap high resolution mass spectrometry(UPLC-Q-Orbitrap HRMS).The samples were extracted with ethyl acetate,then concentrated and dissolved with 30%methanol aqueous solution,and cleaned up using hexane saturated with acetonitrile,amine(NH2) sorbent and MgSO4.The separation was performed on a Thermo fisher Accucore RP-MS(100 mm×21 mm，26 μm) column using acetonitrile and 01%formic acid as mobile phase by gradient elution.The analytes were analyzed in Full MS/dd-MS2(TopN＝1) mode with a heated electrospray ion source(HESI),and quantified by the external standard method.The calibration curves for the 29 analytes were linear in the range of 05-400 μg/L with correlation coefficients not less than 0996 7.The average recoveries at three spiked levels in 5 kinds of product matrixes ranged from 602%to 1233%with relative standard deviations(RSDs,n=6)of 01%-217%.The limits of quantitation were 05-50 μg/kg.With the advantages of simplicity,high precision and good accuracy,the method is suitable for the rapid detection of 29 veterinary drug residues in aquatic products.  
        关键词：quadrupole/electrostatic field orbitrap high-resolution mass spectroscopy(Q-Orbitrap-HRMS);QuEChERS;fish and fishery products;nitroimidazole;benzimidazoles   
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      • Vol. 37, Issue 5, Pages: 556-561(2018)
        摘要：A fluorescence biosensor to detect salmonellae was established based on metal organic frameworks(MOFs) and aptamer.Uio-66-NH2 material has a strong adsorption capacity for FAM labelled aptamers and could completely quench the fluorescence of FAM.The aptamer of nucleic acid has high affinity and high specificity.In the presence of salmonellae,the binding between the FAM labelled aptamer and salmonellae will alter the conformation of FAM labelled aptamer.Therefore,the interaction between the FAM labelled aptamer and MOFs would be disturbed.Such interactions will cause the releasing of the FAM labelled aptamer from the Uio-66-NH2 material,resulting in the restoration of FAM fluorescence.And this method was applied to the estimation of salmonellae in shrimp samples,with the recoveries of 900%-1080%.The fluorescence intensity of the system has a linear relationship with the logarithm of salmonellae concentration in the range of 101-105 cfu/mL,with a detection limit(S/N=3) of 7 cfu/mL.The experimental results showed that the biosensors had a high sensitivity and a high selectivity to salmonellae.  
        关键词：metal organic frameworks(MOFs);aptamer;fluorescence biosensor;salmonellae   
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      • Vol. 37, Issue 5, Pages: 562-569(2018)
        摘要：A QuEChERS phase exaction coupled with ultra high performance liquid chromatography-tandem mass spectrometric(QuEChERS/UPLC-MS/MS) method was developed for the simultaneous determination of 67 pesticide residues in soil.After extraction with acetonitrile,purification with QuEChERS cartridges and dissolution with methanol,the analytes in the sample solutions were analyzed by UPLC-MS/MS on an Agilent Proshell 120 EC-C18 column with a mixture of 01% formic acid solution and acetonitrile as mobile phase by gradient elution.The mass spectrometer was operated in multiple reactions monitoring(MRM) mode under negative and positive modes.Good linearities were obtained for 67 pesticides in the concentration range of 5-500 μg/L with correlation coefficients more than 0990 and detection limits of 0001-0010 mg/L.Recoveries for 67 pesticides at three spiked levels of 10,50,500 μg/kg were in the range of 58%-111%.The relative standard deviations(RSDs,n= 5) were less than 20%,and the limits of quantitation were 10 μg/kg.The established method was simple,efficient and sensitive,and could be applied in the determination of 67 pesticide residues in soil.  
        关键词：ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS);QuEChERS;pesticide residues;soil   
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      • Vol. 37, Issue 5, Pages: 570-575(2018)
        摘要：A high performance liquid chromatography-tandem mass spectrometric（HPLC-MS/MS） method was developed for the determination of the migration of 27 perfluorinated compounds in food contact materials using 3% acetic acid,10% alcohol,50% alcohol and olive oil as food simulants. Samples were soaked in 1 L different kinds of food simulants every 6 dm2 food contact materials according to (EU) No10/2011.The water based simulant samples could be analyzed directly after filteration,and the olive oil stimulant samples should be extracted with acetonitrile before analysis. The simulated solution samples were separated on a C18 column with methanol-water as mobile phase,and analyzed under multiple reaction monitoring（MRM） mode.The results showed that there existed good linearities（r＞0999 1） for 27 perfluorinated compounds in the range of 1-1 000 μg/L.The LOQs of PCFs were in the range of 028-985 μg/kg in food simulants.The recoveries for 27 perfluorinated compounds in blank samples at two spiked levels of 10 and 100 ng ranged from 826% to 1121% with relative standard deviations（RSDs） of 22%-75%.  
        关键词：food contact materials;perfluorinated compounds;liquid chromatography-tandem mass spectrometry;migration   
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      • Vol. 37, Issue 5, Pages: 576-581(2018)
        摘要：An effective method was established for the determination of eight ethylene glycol ethers in cosmetics by gas chromatography-mass spectrometry(GC-MS).Samples were ultrasonically extracted with methanol.The extracts were filtered,and analyzed by GC-MS.The quantitation was carried out by the external standard method.The eight target compounds were baseline separated under optimized chromatographic conditions.Good linearities were obtained in respective linear ranges,with correlation coefficients all larger than 0999.The mean recoveries at three spiked levels ranged from 822% to 1130% with relative standard deviations(RSDs) of 060%-85%.The limits of detection(LODs) were in the range of 010-100 mg/kg and the limits of quantitation(LOQs) were 025- 200 mg/kg.The method is simple,accurate,reliable and reproducible,and could be applied in the determination of ethylene glycol ethers in cosmetics.  
        关键词：gas chromatography-mass spectrometry(GC-MS);cosmetics;ethylene glycol ethers   
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      • Vol. 37, Issue 5, Pages: 582-587(2018)
        摘要：A high performance liquid chromatographic（HPLC） method was established for the simultaneous determination of four kinds of prohibited aldehyde and ketone compounds（crotonaldehyde,acetophenone,2,4 dihydroxy 3 methylbenzaldehyde and 2 pentylidene cyclohexanone） in cosmetics.The samples were extracted with 50% acetonitrile solution,then separated on an AQ-C18（46 mm×150 mm,5 μm） column and detected by HPLC with a diode array detector.The retention time and UV absorption spectra were adopted for qualitation and the external standard method was used for quantitation.The positive cosmetic samples were confirmed by HPLC-MS/MS method.Under the optimal conditions,the results showed that four analytes showed good linearities in the range of 005-20 mg/L with correlation coefficients not less than 0999 9.The limits of detection and quantitation were in the ranges of 05-10 mg/kg and 15-30 mg/kg,respectively.The mean recoveries for the samples at three spiked levels ranged from 890% to 1067% with the relative standard deviations（RSDs,n=6） of 20%-69%.The method is accurate and reliable,and is suitable for the determination of four kinds of prohibited aldehyde and ketone compounds in cosmetics.  
        关键词：high performance liquid chromatography（HPLC）;cosmetics;aldehydes and ketones   
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      • Vol. 37, Issue 5, Pages: 588-593(2018)
        摘要：A magnetic solid phase extraction（MSPE） technique was developed by polymerizing methyl acrylic acid（MAA） on the surface of silica modified Fe3O4 magnetic nanoparticles（Fe3O4@SiO2@MAA MNPs）,which was combined with HPLC-MS/MS method to analyze the tobacco specific N nitrosamines（TSNAs） in mainstream cigarette smoke.In this method,TSNAs were enriched by adding magnetic nano particles to the extract.The separation was fast under the effect of magnetic materials.The eluent was detected by HPLC-MS/MS under multiple reaction monitoring mode,which could meet the requirements for detection of trace TSNAs in low tar and new tobacco products.The results showed that Fe3O4@SiO2@MAA MNPs had the uniform size,good monodispersity and super paramagnetism,on which surfaces the carboxyl functional groups could adsorb TSNAs in the solution for separation and enrichment.The pre treatment method was rapid and simple,and was suitable for analysis on samples of large quantities.The average recoveries for 4 TSNAs ranged from 883% to 1128% with the limits of quantitation（LOQs） of 010-048 μg/L.The method was suitable for the detection of TSNAs with low contents under the complex background.  
        关键词：magnetic solid phase extraction technique（MSPE）;mainstream cigarette smoke;tobacco specific N nitrosamines;HPLC-MS/MS   
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      • Vol. 37, Issue 5, Pages: 594-598(2018)
        摘要：A method was developed for the simultaneous determination of fenbutatin oxide,triphenyltin and cyhexatin pesticide residues in green vegetables and strawberry by gas chromatography-tandem mass spectrometry(GC-MS/MS) with two ionization techniques,ie.electron impact ionization(EI) and positive chemical ionization(PCI).The samples were firstly digested with hydrobromic acid,then extracted with acetone-hexane,finally derived with sodium tetraethylborate.After purification with Florisil solid phase extraction column,the samples were analyzed by GC-MS/MS with EI and PCI sources under SRM mode.Three kinds of organo tin pesticide residues showed good linear relationships in the range of 005-10 mg/L with correlation coefficients larger than 0998.The limits of quantitation for the target objects were in the range of 0019-0042 mg/kg and 0009-0042 mg/kg,respectively,which could meet the requirements for the maximun residue limits(MRLs) of organotin pesticide residues at home and abroad.The average recoveries for three organotin residues at three spike levels of 005,010,020 mg/kg were in the range of 701%-939% with the relative standard deviations less than 10%.With good linearity and high sensitivity,the proposed methods could be used for the determination of organotin pesticide residues in green vegetables and strawberry.Forthermore,the two methods could complement each other to improve the reliabilities of qualitation and quantitation.  
        关键词：gas chromatography-tandem mass spectromety(GC-MS/MS);electron impact ionization (EI);positive chemical ionization (PCI);organo tin;green vegetables;strawberry   
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      • Vol. 37, Issue 5, Pages: 599-603(2018)
        摘要：In order to tune the longitudinal localized surface plasmon resonance(LSPR) wavelength of monodisperse gold nanorods from near infrared to visible light region,monodisperse bimetallic nanorods， with core shell structure based on silver as shell(Au@AgNRs),were synthesized by in situ reduction reaction,and their silver shell thickness could be modulated by the used amount of AgNO3.The morphology,monodispersity and chemical composition of Au@AgNRs were identified by high resolution transmission electron microscopy and X-ray energy dispersive spectroscopy.With the increase of their silver shell thickness,the LSPR effect of Au@AgNRsis was gradually enhanced,and their longitudinal LSPR peak was blue shifted from near infrared to visible light region.When the silver shell thickness was increased 1 nm,the longitudinal LSPR wavelength was decreased about 12 nm.The prepared Au@AgNRs has a good application prospect in visualization sensor.  
        关键词：gold nanorod;silver shell;localized surface plasmon resonance(LSPR) optical property;longitudinal LSPR wavelength;visualization sensor   
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      • Vol. 37, Issue 5, Pages: 604-609(2018)
        摘要：A gas chromatography-mass spectrometric method was established for the determination of karanal in textiles.Karanal in textiles was ultrasonically extracted using methanol as extraction solvent.The extract was then analyzed by gas chromatography-mass spectrometry in selected ion monitoring mode(GC-MS/SIM).The concentration of karanal was calibrated by the external standard method.The limit of detection was 01 mg/kg.Good linearity existed between peak area and the mass concentration of karanal in the range of 014-2818 mg/L.The average recoveries at three spiked levels of 071,282 and 705 mg/kg changed from 873% to 961%.The precision(RSD,n=9) varied from 058% to 24%.The proposed method was simple,accurate,and convenient to operate.It was appropriate for the determination of karanal in textiles in routine tests.  
        关键词：textile;karanal;gas chromatography-mass spectrometry/selected ion monitoring(GC-MS/SIM);ultrasonic extraction   
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      • Vol. 37, Issue 5, Pages: 610-614(2018)
        摘要：Based on the charge transfer reaction between bisphenol-S(BPS) and borax,a simple and rapid method was developed for the determination of BPS by ultraviolet spectrophotometric method.The results indicated that in water medium,BPS could form charge transfer complex with borax,and its maximum absorption wavelength was 291 nm.The apparent molar absorptivity was 192×104 L·mol-1·cm-1.Beers law was obeyed for BPS in the concentration range of 07-7 mg/L.The correlation coefficient was 0999 6,and the detection limit was 0195 μg/mL.The proposed method was applied in the determination of BPS in samples with satisfactory results.The recoveries for BPS were in the range of 998%-1004% with RSDs(n=5) not more than 05%.  
        关键词：bisphenol-S(BPS);borax;charge transfer reaction;UV   
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      • Vol. 37, Issue 5, Pages: 615-620(2018)
        摘要：A high performance liquid chromatography(HPLC) method combined with a rapid and simple pretreatment approach was established for the determination of five fluoroquinolones(ciprofloxacin,danofloxacin,enrofloxacin,difloxacinand and sarafloxacin) residues in eggs.Samples were extracted with acetonitrile.Protein in egg samples was precipitated by heating in water-bath.The supernatants were degreased with n hexane,and followed by HPLC analysis.The mobile phase consisted of 005 mol/L phosphoric acid and triethylamine-acetonitrile(80∶20).The fluorometric excitation wavelength was 280 nm,and the emission wavelength was 450 nm.The limits of quantitation(LOQ) for ciprofloxacin,difloxacin,danofloxacin,enrofloxacin and sarafloxacin were 5,5,05,25 and 10 μg/kg,respectively.The average recoveries for 5 fluoroquinolones were in the range of 922%-1071% at four spiked levels(LOQ,2 LOQ,4 LOQ and 20 LOQ),and the intra day and inter day relative standard deviations(RSDs) were in the ranges of 06%-58% and 15%-50%,respectively.The proposed method is rapid,accurate,sensitive and eco friendly,and could be used for the quick analysis on residues of fluoroquinolones in egg in its production and distribution for consumption.  
        关键词：HPLC;fluoroquinolones;residue;egg;rapid determination   
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      • Vol. 37, Issue 5, Pages: 621-625(2018)
        摘要：In this paper,a self assembled impedance immune sensor was constructed to detect trace Tau protein in order to achieve the purpose of early diagnosis on Alzheimer disease.The sensor was constructed and characterized by the following steps:the bifunctional molecule 3,3′ dithiobis(sulfosuccinimidylpropionate) (DTSSP) was modified on the gold electrode surface through the Au-S bond,which was then conjugated with antibodies 39E10 through the CO-NH.Tau protein was specifically captured by physisorption using immunoassay,characterized by AC impedance and verified by cyclic voltammetry.By optimizing the DTSSP modification time and antibody concentration,the sensor had a detection signal toward Tau protein of 002-100 μg/mL,in which there existed a good linearity(r2=0988 8) in the concentration range of 02-20 μg/mL with a detection limit of 043 nmol/L.This immunosensors specific capture ability for Tau could be used as a supplementary means for clinical detection on AD.  
        关键词：electrochemistry;impedance;immunity;Alzheimer disease(AD);tau protein   
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      • Vol. 37, Issue 5, Pages: 626-629(2018)
        摘要：A method was developed for the determination of paraquat and diquat residues in water by high performance liquid chromatography-tandem mass spectrometry with solid phase extraction.The samples were cleaned up by Cleanert PWCX solid phase extraction,separated on a HILIC column using acetonitrile-5 mmol/L ammonium acetate（pH 37 with formic acid） as mobile phase by gradient elution,then detected in SRM mode and quantified by external standard method with the matrix matched calibrations.The calibration curves for paraquat and diquat showed good linearities in the concentration ranges of 100-2000 μg/L and 10-2000 μg/L,respectively,with correlation coefficients（r2） no less than 0997.The average recoveries for paraquat and diquat in agricultural environmental water at spiked levels of 30-200 μg/L were in the ranges of 968%-1258% and 972%-1182%,with intra assay relative standard deviations（RSDs） of 30%-63% and 29%-60%,and inter assay relative standard deviations of 33%-82% and 27%-79%,respectively.The limits of detection（LODs） and quantitation（LOQs） of the method were 50 μg/L and 03 μg/L,and 100 μg/L and 10 μg/L,respectively.The results indicated that the developed method is easy,fast and sensitive,its indicators such as the linear range,recovery,precision and detection limit could meet the requirements for residue analysis.The method is suitable for the determination of paraquat and diquat in agricultural environmental water  
        关键词：water;paraquat;diquat;solid phase extraction（SPE）;high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）;pesticide residues   
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      • Vol. 37, Issue 5, Pages: 630-634(2018)
        摘要：A zinc metal-organic framework material,{［Zn（FDC）］· H2O}n（Zn-MOF）,was synthesized with 2,5 furandicarboxylic acid（H2FDC） and zinc nitrate hexahydrate as raw materials,and N,N dimethylformamide and water as the mixed solvent.The fluorescent properties of the material were characterized,and the results showed that the strongest fluorescence emission peak occurred at 470 nm when using an excitation wavelength of 350 nm.The effects of 15 metal ions in food on fluorescence intensity of the material were investigated.It was found that Hg2+ could selectively quench the fluorescence of the material.In addition,the effects of different Hg2+ concentrations,different soaking times and Hg2+ on the sensitivity of fluorescence quenching were also investigated.The results showed that the zinc metal-organic framework material has a highly selective sensing ability toward Hg2+,which could be utilized in the detection of Hg2+ residue in food.Hg2+ could be efficiently detected by fluorescence spectroscopy with this Zn-MOF material as a fluorescent probe.  
        关键词：zinc metal organic framework material（Zn-MOF）;fluorescence spectrometry;Hg2+;selective sensing   
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      • Vol. 37, Issue 5, Pages: 635-638(2018)
        摘要：A method for the determination of advantame in foods using high performance liquid chromatography（HPLC） was developed.The samples were extracted with methanol-water（50∶50,by volume） in ultrasonic condition for 10 min.The supernatant was analyzed after centrifugation.Target compound was separated on an Agilent TC-C18（2）（250 mm×46 mm,5 μm） column at 280 nm,with methanol-002 mol/L ammonium acetate（53∶47,by volume） as mobile phase by isocratic elution.The quantitative analysis was carried out by the external standard method.The results showed that the calibration curves were linear in the range of 10-2000 mg/L with correlation coefficients of 0999 8.The limits of detection（S/N≥3） of the method for the analytes in beverage,yoghourt and cake were 06，15 and 90 mg/kg,respectively.The average recoveries ranged from 909% to 1034% with relative standard deviations（RSDs,n=5） of 11%-45%.With the advantages of good separation,few impurity disturbances and high accuracy,this method could be applied in the analysis of advantame in real samples.  
        关键词：high performance liquid chromatography（HPLC）;determination;food;advantame   
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