最新刊期
卷 35 ， 期 3 ， 2016
- 摘要：A method was developed for the screening,confirmation and quantification of perfluorinated compounds in textiles by liquid chromatography-ion trap-time of flight-tandem mass spectrometry (LC-MS-IT-TOF) combined with dispersive solid phase extraction.The multiple stage fragments ion mass spectrometry database of 14 target compounds was established.The analytes in samples were extracted with methanol under ultrasonic extraction,and the extract was cleaned up with a C18 sorbents.In the chromatographic analysis,14 target compounds were separated on a C8 chromatographic column(150mm×4.6mm,3.5μm) by gradient elution using methanol-5mmol/L ammonium acetate as mobile phase.The effects of species and dosages of the sorbents on recoveries of 14 target compounds were studied,and the purification conditions were optimized.The results showed that the method detection limits of the target compounds ranged from 1μg/kg to 10μg/kg. The average recoveries of 14 compounds at three spiked concentration levels(10,50,100μg/kg) were in the range of 49.2%-101.4% with relative standard deviations(RSDs) of 1.1%-14.0%．The screening of analytes was performed by precision mass matching acquired by full scanning and library searching.The confirmatory analysis for target compounds was performed with the retention time and qualitative fragments.This method is simple,fast,credible and highly sensitive.It could be applied in the simultaneous screening and identification of perfluorinated compounds in textiles.关键词：textiles;perfluorinated compounds;ion trap-time of flight tandem mass spectrometry (IT-TOF-MS);screening;dispersive solid phase extraction;high performance liquid chromatography
- 1924
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- 1435
- |
- 6
发布时间： - 摘要：Taking into account the high number of synthetic cannabinoids found in seized novel “spice” drugs in recent years,this study aimed at the simultaneous determination of common synthetic cannabinoids.An HPLC-MS/MS method was developed for the determination of ten synthetic cannabinoids in novel “spice” drugs.Samples were dissolved with methanol,and then ultrasound assistedly extracted and filtered through a 0.22μm membrane filter.The extract was separated on an Agilent Poroshell 120 EC-C18(3.0mm×50mm，2.7μm) column at 30℃,using methanol-water as mobile phase.The flow rate was set at 0.3mL/min.ESI+ and ESI- mode were used at different times,and the MS spectra characteristics and proposed fragmentation of 10 synthetic cannabinoids were studied.Under the optimized conditions,good linear relationships were obtained in the ranges of 1-100ng/mL for 7 synthetic cannabinoids under ESI+ mode,and 10-1000ng/mL for 3 synthetic cannabinoids under ESI- mode.The intra-day relative standard deviations(RSDs) were not more than 3.2% and the inter-day RSDs were not more than 6.3%.This method was applied in real cases,and was proved to be fast,accurate,sensitive and precise for the determination of those 10 common synthetic cannabinoids in novel “spice” drugs.关键词：high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS);spice;drugs;synthetic cannabinoids
- 2027
- |
- 1204
- |
- 10
发布时间： - 摘要：The haptens 4-{4-［2,2,2-trichloro-1-(4-chloro-phenyl)-ethyl］-phenyl}-butyric acid(DDT-H1)，4-［4-(2,2,2-trichloro-1-p-tolyl-ethyl)-phenyl］-butyric acid(DDT-H2) were designed and synthesized on the basis of characteristics part of DDT,and artificial antigens DDT-H1-BSA(immmue antigen),and DDT-H1-OVA.DDT-H2-OVA(coating antigens) were prepared by coupling with the carrier proteins using active ester method and mixture anhydrides method,respectively.The monoclonal antibody(MAb) against DDT was produced by immunity DDT-H1-BSA,cell fusion, screening,cloning. The MAb was prepared from ascetic fluids of Balb/c,which was purified with saturated ammonium sulfate followed by affinity chromatography on protein A.The monoclonal antibody characterized by IgG1 isotype showed a high cross-reactivity to some metabolites.The enzyme linked immunosorbent assay(ELISA) titer of ascites was 1.68×105,and the affinity of antibody(Ka) was 5.238×1011 L?mol-1.An indirect competitive ELISA was founded base on the monoclonal antibody.The results of indirect competitive ELISA showed that the linear range of the calibration curves ranged from 6.6ng/mL to 521.8ng/mL.The method could be applied in the detection of DDT and its metabolites in agriculture products and environment.关键词：dichlorodiphenyltrichloroethane(DDT);monoclonal antibody;ELISA;metabolites
- 2029
- |
- 1328
- |
- 3
发布时间： - 摘要：A novel DNA biosensor was fabricated with three-dimensionally ordered macroporous gold-nanoparticle-doped titanium dioxide(3DOM GTD) film on the indium-tin oxide(ITO) electrode surface by the colloidal crystal template technique,and calf thymus DNA(ctDNA)was immobilized on the 3DOM GTD/ITO successfully.The morphology of the modified electrode was characterized by transmission electron microscopy(TEM) and scanning electron microscopy(SEM).The immobilization of ctDNA on the surface of 3DOM GTD/ITO modified electrode was investigated by electrochemical impedance spectroscopy(EIS).The EIS experimental results showed that ctDNA was successfully immobilized on the 3DOM GTD/ITO modified electrode.The electrochemical properties of the antitumor drug quercetin (Qu) and the interaction between Qu and ctDNA were studied on 3DOM GTD/ITO modified electrode by cyclic voltammograms (CV) and differential pulse voltammograms(DPV) method.The result showed that Qu had a pair of quasi-reversible redox peak on 3DOM GTD/ITO modified electrode,and the transfer process of 2 electrons and 2 protons was an involved in the electrode reaction.There was a strong interaction between Qu and ctDNA immobilized on the modified electrode,and the binding constant K was 3.61×106L/mol.The binding mode between Qu and ctDNA was an intercalation confirmed by CV,UV-Vis absorption spectra (UV-Vis),fluorescence spectra(FL) and circular dichroism spectra(CD) experiments. The sequence selectivity of binding between Qu and ctDNA was investigated,and the binding constants of Qu and poly(dG-dC) and poly(dA-dT) were calculated, respectively, according to the results of CV experiments.The binding constant ratio K(dG-dC)/K(dA-dT) was obtained to be 3.5,indicating that Qu bound to the GC region preferentially when Qu interacted with ctDNA.关键词：Three-dimensionally ordered macroporous(3DOM);gold-nanoparticle-doped titaniumdioxide(GTD);DNA modified electrode;quercetin (Qu);intercalation;sequence selectivity
- 1937
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- 1289
- |
- 1
发布时间： - 摘要：A high performance liquid chromatographic (HPLC) method for the determination of 11 adulterated drugs (acetaminophen,aspirin,salicylic acid,sulfapirazinmetossina,sulfadiazine,sulfamethazine,ofloxacin,ciprofloxacin,lomefloxacin,terramycin and doxycycline) in herbal tea was developed.The samples were extracted ultrasonically with methanol-acetonitrile (1∶1),and the extracts were separated on an Agilent Poroshell 120 EC C18 column (100 mm×4.6 mm,2.7 μm) with trifluoroacetic acid triethylamine (pH 3.0)-methanol-acetonitrile as mobile phases by gradient elution.The flow rate was 1.2 mL/min and the column temperature was 35 ℃.Identification of 11 compounds was achieved by the comparison of the chromatographic peaks retention times and the DAD spectra between the samples and reference substances.Quantification analysis was performed by the external standard method.The calibration curves showed good linearities in the range of 0.5-25 mg/L with correlation coefficients not less than 0.998 2.The detection limits of 11 compounds ranged from 1 mg/L to 5 mg/L.The average recoveries ranged from 86.9% to 108.0% with RSDs of 0.5%-1.4%.The method was applied in the analysis of 286 herbal tea samples,and 9 positive samples containing acetaminophen,aspirin,salicylic acid and sulfapirazinmetossina were found.The positive samples were further identified and verified by HPLC-MS/MS.The experimental results indicated that the proposed method was simple,sensitive and accurate,and was suitable for the determination of 11 adulterated drugs in herbal tea.关键词：fused-core sub-3 μm particle column;herbal tea;adulteration;drugs;high performance liquid chromatography (HPLC)
- 2053
- |
- 1392
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- 8
发布时间： - 摘要：In this study,tannic acid(TA) functionalized graphene nano sheets(TA-G) was facilely synthesized through a one-step green reduction method using tannic acid as dual function agent，in which tannic acid acted as not only a reduction reagent to reduce oxided graphene(EGO) but also a capping reagent to functionalize graphene.The as prepared TA-G was used to construct a graphene based rutin electrochemical sensor,and the modified electrode had a high sensitivity for rutin detection.The results of electrode reaction kinetics of rutin on TA-G modified electeochemical sensor indicated that the electeochemical reaction of rutin on the modified electrode undergone a surface controlled quasi reversible electrochemical process.The optimal conditions were as follows:pH value:3.0,TA-G amount(1.0 μg/mL) on TA-G modified electrochemical sensor:8 μL,scan rate:100 mV/s,cycles of enrichment:100.Under the optimal conditions,the fabricated sensor displayed an excellent analytical performance for rutin detection,with a linear range of 1.0×10-8-1.0×10-5 mol?L-1 and a low detection limit of 6.0×10-9 mol?L-1 at 3σ.Meanwhile,the fabricated rutin electrochemical sensor also exhibited good selectivity,specificity and stability,and could be used for rutin detection in real samples.The proposed method broadened the application field of graphene and offered a new idea for rapid detection of drug.关键词：tannic acid functionalized graphene;electrochemistry;modified electrode;rutin;sensitive detection
- 1829
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- 1123
- |
- 2
发布时间： - 摘要：In the present method for aflatoxin detection,the low-end devices could not be applied in quantitation of multi-components,while the high-end devices are hard to be used in small labs due to the high cost and large volume.In this situation,a miniaturized aflatoxin analyzer was constructed based on micellar electrokinetic capillary chromatography with light emitting diode（LED） induced fluorescence detector.The main parts of the apparatus were chosen as follows:A UV LED was used as the light source,two band pass filters including BP 365 and BP 430 were used for the excitation light and the fluorescence,respectively,ultra violet hard clad silica(UVHCS) fiber was used to direct the fluorescence,and photomultiplier tube（PMT） was used as the detection element.The buffer composition was investigated and the optimized conditions were found.Under the optimal conditions,baseline separation of six aflatoxins was achieved.Good linearities were obtained over the concentration range of 0.1-10 μg/L for six compounds with correlation coefficients larger than 0.99.The intra-RSDs were in the range of 2.0%-2.4%,while the inter-RSDs were 5.1%-6.0%,respectively.The limits of detection for six compounds were in the range of 0.3-0.8 μg/kg,with recoveries of 85.3%-97.0%.With the advantages of small volume and low cost,as well as the elimination of derivatization and organic reagent,this analyzer could be widely used for the multi-aflatoxin quantitation in food analysis.关键词：aflatoxin;fluorescence;light emitting diode;analyzer
- 1989
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- 1269
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- 2
发布时间： - 摘要：A rapid method was developed for the quantitative analysis of perfluorinated compounds（PFCs) including perfluorooctane sulfonic acid（PFOS）,perfluorooctanoic acid（PFOA）,perfluoroundecanoic acid（PFUnA）,perfluorododecanoic acid（PFDoA）,perfluorotridecanoic acid（PFTrDA）,perfluorotetradecanoic acid（PFTA） in coastal and estuarine seawater by solid phase extraction（SPE） enrichment with ultra high performance liquid chromatography tandem electrospray ionization mass spectrometry（UHPLC-MS/MS）.Seawater sample was enriched and purified through a 500 mg C18 SPE cartridge at 5.0 mL/min,eluted with 15 mL mixed solvent of methanol and ethyl acetate（4∶1）, and finally concentrated into 1.0 mL with an automated de-solvent device.Target analytes were separated on a Kinetex XB-C18 column using methanol（containing 5.0 mmol/L NH4COOH-water（containing 5.0 mmol/L NH4COOH） as mobile phase.The negative electrospray ionization（ESI-） and multiple reaction monitoring mode（MRM） were utilized.An internal standard calibration method was chosen for the quantitative analysis.The calibration curves of PFCs were linear in the range of 0.5-50.0 μg/L with correlation coefficients more than 0.999 0.The limits of quantitation（LOQs,S/N=10） were between 0.5 ng/L and 1.5 ng/L.The recoveries of 6 PFCs at three spiked levels（2.0,5.0,10.0 ng/L） were in the range of 80.1%-117.4%,and relative standard deviations（RSDs） were 8.2%-12.1% at spiked level of 2.0 ng/L.关键词：perfluorinated compounds;coastal and estuarine seawater;ultra high performance liquid chromatography tandem mass spectrometry（UHPLC-MS/MS）;solid phase extraction
- 2008
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- 1177
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- 6
发布时间： - 摘要：With water as an extractant,a method was established for the determination of furoic acid in transformer oil by reversed phase liquid-liquid microextraction(RLLME) coupled with high performance liquid chromatography(HPLC).The effects of some important parameters,such as pH value and amount of extractant,amount of the diluent(n-hexane),extraction time and centrifugal rotational speed were investigated.The optimum experimental conditions were as follows:extraction solvent:neutral ultrapure water;amount of extractant:150 μL;ratio of dilution:Voil∶Vn-hexane=3∶1;extraction time:5 min;centrifugal rotational speed:5 500 r/min.The quantitative analysis of furoic acid in the transformer oil sample was performed by HPLC.The calibration curve was linear in the range of 0.05-5.00 mg?L-1 with a correlation coefficient(r)of 0.999 9 and a detection limit of 9.6 μg?L-1.The relative standard deviation(RSD,n=6) was 1.4%and the enrichment factor of furoic acid was 13.6.The recoveries of furoic acid in aging transformer oil sample ranged from 99.7%to 105.1%.The qualitative analysis of furoic acid in aging transformer oil was further carried out by using HPLC-MS.This study has established a simple and effective method for the detection of furoic acid in transformer oil and provided useful data for the research on the aging characteristic parameters of transformer oil-paper insulation.关键词：reversed phase liquid-liquid microextraction;high performance liquid chromatography(HPLC);furoic acid;transformer oil
- 1861
- |
- 1158
- |
- 2
发布时间： - 摘要：By using cyclic voltammetry,eosin Y film was electrodeposited on the surface of glassy carbon electrode(GCE) to obtain the modified electrode(denoted as eosin Y/GCE). The electrochemical properties of eosin Y/GCE were studied by electrochemical impedance spectroscopy.The electrocatalysis capability of eosin Y/GCE to tertiary butyl hydroquinone(TBHQ) was investigated by cyclic voltammetry(CV) and differential pulse voltammetry(DPV) .Compared with the bare GCE,eosin Y/GCE exhibited outstanding electrocatalytic activity and reversibility towards the oxidation of TBHQ.The oxidation and reduction peak separation was decreased from 297 mV to 85 mV for TBHQ at eosin Y/GCE.Influence of different scan rates(20-400 mV?s-1) on redox of TBHQ was further examined at the eosin Y/GCE.The oxidation and reduction peak currents were linear to the square root of scan rate,indicating that the diffusion controlled process of TBHQ occurred at the eosin Y/GCE surface.Under the optimal conditions,the DPV response of the modified electrode was linear to TBHQ concentration in the range of 1-200 μmol?L-1 with a detection limit of 0.1 μmol?L-1.Moreover,eosin Y/GCE exhibited excellent selectivity,reproducibility and long-term stability,and was successfully applied in the determination of TBHQ in soybean oil samples with recoveries of 95.0%-102.5%.This modified electrode could be used as a promising sensing platform for the determination of different antioxidants in food samples.关键词：eosin Y;tertiary butyl hydroquinone;cyclic voltammetry(CV);differential pulse voltammetry(DPV);food additives
- 1925
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- 1251
- |
- 0
发布时间： - 摘要：A method was developed for the simultaneous determination of hexoestrolum,diethylstilbestrol,dienestrol,estrone,17β-estradiol and estriol in feed by solid phase extraction and gas chromatography-mass spectrometry(GC-MS).After extracted with ethyl ether and cleaned up on an HLB phase extraction column,six kinds of estrogens were derived and quantified by GC-MS.The external standard calibration curves were used for the quantification.The results showed that the high linear ranges from 2.5 ng/mL to 250 ng/mL for hexoestrolum and from 5 ng/mL to 500 ng/mL for five other estrogens were obtained with correlation coefficients (r2) not less than 0.99.The limits of detection were in the range of 3-8 μg/kg and the average recoveries were 75.9%-96.3%.The results demonstrated that the developed method could be applied in the qualitative and quantitative determination of six kinds of estrogens in feed with low limit of detection and high accuracy.关键词：gas chromatography-mass spectrometry(GC-MS);hexoestrolum;diethylstilbestrol;dienestrol;estrone;17β estradiol;estriol;feed
- 1988
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- 1276
- |
- 7
发布时间： - 摘要：An HPLC-APCI(+)-MS-MS method was developed for the determination of vitamin D2(VD2) and vitamin D3(VD3) in dairy products.The sample was saponified,and then extracted with petroleum ether.Next,the extract was dried with anhydrous sodium sulfate and concentrated below 10 mL via rotary evaporation under the protection of nitrogen.Then it was dried with nitrogen and dissolved with 10 mL methanol.The extract was analyzed by HPLC-APCI(+)-MS-MS using an ACQUITY UPLC BEH C18 column(1.7 μm,2.1 mm×100 mm) as chromatographic column with a mobile phase of methanol and water under gradient elution.The responses of VD2 and VD3 showed good linearities in the range of 0.01-0.2 mg/L,with correlation coefficients more than 0.998. The average recoveries were in the range of 83.0%- 99.4%,with RSDs of 2.0%- 8.3%.关键词：high performance liquid chromatography-triple quadrupole mass spectrometry(HPLC-MS/MS);atmospheric pressure chemical ionization mass spectrometry;vitamin D2;vitamin D3;dairy products
- 1945
- |
- 1112
- |
- 7
发布时间： - 摘要：β-tricalcium phosphate(β-TCP) was modified by using stearic acid,and the mechanism of interfacial interactions between β-TCP particles and stearic acid was studied by transmission electron microscopy(TEM),thermal gravimetric analyzer(TGA) and X-ray photoelectron spectroscopy(XPS).The β-TCP/PLLA and modified β-TCP/PLLA composite nanofiber membranes of different quality ratios were prepared by electrospinning.Their morphologies were observed by using scanning electron microscope(SEM) and their mechanical properties were also studied.The results indicated that the stearic acid was coated on the surface of β-TCP particles,and modified β-TCP was hydrophobic.H+ of stearic acid could produce protonation reaction with O of PO3-4 from β-TCP and then generate —OH.The modification of β-TCP particles by stearic acid could reduce their agglomeration and obtain the continuous and uniform nanofibers.The mechanical properties of the modified β-TCP/PLLA composite nanofiber membranes were improved more significantly than that of β-TCP/PLLA.关键词：β-tricalcium phosphate;surface modification;morphology;surface perssad;mechanical properties
- 1835
- |
- 1143
- |
- 0
发布时间： - 摘要：A rapid new method for the determination of benzalkonium chloride (BAC) in eye drops complex system was developed with ultraviolet spectrum based on oblique projection (OP) and space angle criterion (SAC),in which the content of BAC is based on content of dodecyl dimethyl benzyl ammonium chloride (1227) .By treatment with oblique projection,the pure spectrum of dodecyl dimethyl benzyl ammonium chloride was obtained.The standard spectral matrix was set up by the least squares fitting the spectrum with the corresponding concentration.And then the background spectral matrix was obtained by using high performance liquid chromatography-ultraviolet spectrum(HPLC-UV).After that the contents of 1227 in different kinds of eye drops were calculated by using space angle criterion,and the content of BAC was obtained.The results indicated that the method exhibited a good linearity (r＞0.999 6) for BAC in the range of 1-20 μg/mL.The determination results of this method is close to that of HPLC method,and the relative error is not more than 2.3%.The recoveries were obtained between 99.6% and 101.8%,with RSDs not more than 2.8%.The content of BAC could be directly obtained with multiple wavelength ultraviolet spectrum without complicated sample preparation,and the method has the advantages of short quantitative time,high analysis efficiency,good robustness,and could provide a feasible scheme for the detection of analyte of interest in other complex system.关键词：oblique projection;space angle criterion;high performance liquid chromatography-ultraviolet spectrum(HPLC-UV);benzalkonium chloride;eye drops
- 1935
- |
- 1117
- |
- 3
发布时间： - 摘要：A method of high performance liquid chromatography（HPLC） combined with LTQ-Orbitrap XL mass spectrometry was developed for the analysis of salicin,a characteristic component of poplar tree gum in propolis.With the exact parent ion and fragment ion， whether the propolis contains poplar tree gum could be confirmed.The samples were extracted with ethyl alcohol.The LC separation was performed on a Waters xselect HSS T3（3.0 mm×100 mm，3.5 μm） column with acetonitrile-0.1% acetic acid solution as mobile phase.The analyte was detected under positive mode.The calibration curve showed a good linearity within the concentration range of 0.5-25.0 μg/mL.The average recoveries of salicin ranged from 81.6% to 91.0% at the spiked levels of 25.0，150.0，300.0 mg/kg with relative standard deviations（RSDs） less than 11.6%.The developed method was simple，sensitive and repeatable，and could be used as a screen and confirmatory approach for the analysis of salicin in propolis.关键词：high performance liquid chromatography（HPLC）;linear ion trap-orbitrap mass spectrometer（LTQ-orbitrap MS）;high resolution mass spectrometry（HRMS）;propolis;poplar tree gum;salicin
- 1836
- |
- 1232
- |
- 2
发布时间： - 摘要：A rapid,sensitive method based on membrane enrichment-solid phase UV spectrometry for the determination of 2-naphthol in tapwater was developed.The enrichment material is nylon membrane（pore size:0.22 μm）.UV spectrum of 2-naphthol was acquired after enrichment without further treatment for quantitative analysis.The method is rapid and sensitive.The influences of pH value,sample volume,and vacuum degree were optimized,and the analysis capacity was evaluated.The result showed that there is a quadratic relationship between UV absorbance（wavelength:331 nm） and concentration of 2-naphthol in the range of 0.3-10 mg/L.There are two linear relationships in the ranges of 0.3-1.0 mg/L and 1.0-10 mg/L with correlation coefficients of 0.999 1 and 0.995 5,respectively.Under the optimum conditions,the limit of detection（LOD） was 0.265 6 mg/L.The accuracy and precision of the method are satisfactory,which could be used for the detection of 2-naphthol in tapwater.关键词：membrane enrichment;solid phase UV spectrometry;2-naphthol;water
- 2119
- |
- 1223
- |
- 3
发布时间： - 摘要：A simple and sensitive method was developed for the determination of dinotefuran residues in brown rice,hull,straw and soil.The residues of dinotefuran in different matrix were extracted with acetonitrile.After cleaned with PSA column,the extract was separated on an Agilent ZORBAX SB-C18 analytical column,and determined by liquid chromatography-tandem mass spectrometry（LC-MS/MS） under multiple reaction monitoring（MRM） mode.The method was validated at different fortification levels in brown rice,hull,straw and soils.The recoveries for brown rice at three fortification levels ranged from 73.8% to 97.2% with relative standard deviations（RSDs） not more than 9.9%.The recoveries for hull were between 77.6% and 80.3% with RSDs not more than 5.8%.The recoveries for straw were between 76.0% and 94.0% with RSDs not more than 8.8%.The recoveries for soil were between 83.6% and 93.3% with RSDs not more than 6.4%.The results showed that the method is simple and rapid,and its sensitivity and accuracy could meet the requirements for pesticide residue analysis.关键词：dinotefuran;rice;soil;solid phase extraction(SPE);liquid chromatography-tandem mass spectrometry（LC-MS/MS）
- 1977
- |
- 1313
- |
- 3
发布时间： - 摘要：An analytical method based on high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) was developed for the determination of perchlorate in fruits.Samples were extracted with 1% acetic acid.The extract was cleaned up on an C18 solid-phase extraction(SPE) cartridge,and separated on a Waters IC-Pak Anion HR column(4.6 mm×75 mm) using acetonitrile -100 mmol/L ammonium acetate(60∶40) as mobile phase at a rate of 0.7 mL/min.The detection of perchlorate anion was performed by high performance liquid chromatography triple stage quadrupole mass spectrometry,equipped with electrospray ionization(ESI) in the negative ion mode.An 18O labelled perchlorate anion internal standard was used to correct matrix effects.Quantification analysis was conducted by the internal standard calibration.Good linearity was observed for perchlorate in the concentration range of 0.1- 10.0 μg/L.The limit of quantitation was 1.0 μg/kg.The recoveries of perchlorate in different samples at three spiked levels of 1.0,2.0,10.0 μg/kg were in the range of 92.5%-110%,with relative standard deviations of 1.4%-5.4%.The real sample analysis showed that this method was accurate and could be applied in the determination of perchlorate in fruits.关键词：perchlorate;18O-labelled perchlorate dilution;solid phase extraction;high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS);fruits
- 2092
- |
- 1283
- |
- 10
发布时间： - 摘要：The determination techniques of heavy metals in tobacco products and smoke were reviewed with regard to sample preparation and detection methods.The methods for sample preparation including wet digestion,microwave digestion,extraction method,slurry sampling and other methods,and the detection methods including atomic spectroscopy,mass spectrometry and liquid chromatography were introduced.The sensitivity,accuracy and application of these methods were described.The advantages and disadvantages of various methods were compared.The development of the detection methods for the heavy metals in tobacco were also prospected.关键词：tobacco products;smoke;heavy metals;sample preparation;detection method;review
- 1933
- |
- 996
- |
- 4
发布时间： - 摘要：The structural research and composition analysis of carbohydrates play important roles in disclosing their biological functions.Meanwhile,the derivation analysis is an efficient approach for the qualitative and quantitative detection of carbohydrates with high sensitivity.This paper reviewed a derivative method using 1-phenyl-3-methyl-5-pyrazolone（PMP） as reagent,which is mild,sensitive and highly selective,and is widely used in the analysis of monosaccharide composition,degree of polymerization，degree of substitute,disaccharides isomers ,as well as relative quantitation and structural identification of O-and N-glycans.关键词：1-phenyl-3-methyl-5-pyrazolone（PMP）;derivative approach;carbohydrate analysis;review
- 1974
- |
- 1300
- |
- 17
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