最新刊期
卷 30 ， 期 2 ， 2011
- 摘要：An optical method for the detection of potassium ion based on the conformational change of aptamer and fluorescent probe thiazole orange（TO）was reported.Anti K+ aptamer was hybridized with its complementary strand which has a single base mutation and is shorter than aptamer.TO exhibited stronger fluorescence when it interacted with the double strand DNA mentioned above.The fluorescence emission intensity of TO decreased when double strand DNA was dehybridized due to the formation of G quadruplex structure and single strand DNA in the presence of K+.The influences of TO concentration,temperature and time on the sensing of K+ were investigated.Under the optimum reaction conditions,a good linear relationship was found between the fluorescence decreasing ratio（I0F-IF）/I0F and the potassium ion concentration in the range of 10×10-6-20×10-4 mol/L,and a sensitive detection limit of 33×10-7 mol/L was obtained.Contrast experiments with other ions such as Li+,Na+,Ca2+,Mg2+ and NH+4 showed that this method was label free,simple and economical,and could be used for the determination of K+ in potassium penicillin V tablets with good sensitivity and specificity for K+.The results obtained by this method were in agreement with those from atomic absorption spectrophotomertic analysis.关键词：thiazole orange;potassium ion;aptamer
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发布时间： - 摘要：Inverted microscope,atomic force microscope(AFM),CCK 8 and flow cytometer were used to study the toxicity of curcumin on human hepatoma HepG2 cells qualitatively and quantitatively.The AFM results indicated that curcumin could induce the deformation change of HepG2 cells to varying degrees.The volume and height of the cells decreased with the increase of cell deformation,whereas,the mean roughness(Ra),mean square root roughness(Rq) and granularity distribution of HepG2 cell surface increased with the increase of cell deformation.Through detecting the mechanical property of the cells by AFM,it was found that the relative adhesion force of the cell surface decreased from （7084±2557） pN to （2998±396） pN when 40 μmol/L curcumin was incubated with HepG2 cells for 24 h.By means of CCK 8 assay,it was found that the HepG2 cell viability was related with the reaction time and drug concentration.When 20-80 μmol/L curcumin were incubated with HepG2 cells for 24 h and 48 h,respectively,the cell viability declined from（722±38）% to （106±23）% and （536±27）% to （87±18）%,respectively.In addition,the result of cell cycle analysis by flow cytometer showed that curcumin could block the HepG2 cell in G2/M phase.The results obtained above are of significance to the visual diagnosis of drug induced early apoptosis in cancer cells,and to the study of the drugs-cells interaction.关键词：AFM;curcumin;cytotoxicity;surface roughness;adhesion force;ultrastructure
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发布时间： - 摘要：A comprehensive analytical method based on high performance liquid chromatography-electrospray ionization tandem mass spectrometry（HPLC-ESI MS/MS） under positive ionization mode was developed for the determination of 6 plant growth retardants（PGRs） residues，including choline chloride，chlormequat chloride，mepiquat chloride，ancymidol，paclobutrazol and uniconazole in fruits and vegetables.The samples were extracted with methanol by ultrasonic wave assistant extraction（UAE）.The extract was purified and concentrated by solid phase extraction（SPE） with Waters Oasis HLB column（3 mL，60 mg）.The separation of the target compound was performed with Thermo Hypersil Gold aQ（21 mm×150 mm，3 μm） column by gradient elution.The identification of 6 PGRs was carried out by ESI under the positive ion mode.Effects of mobile phase and additives on ionization were investigated.Effects of the types and amounts of extraction solvents and the types of SPE column were also studied.Under the optimal conditions，the calibration curves of 6 PGRs were linear in the range of 10-2000 μg/L with correlation coefficients（r） more than 099.Recoveries of 6 PGRs at three spiked concentration levels of 20，100,500 μg/kg ranged from 81% to 104% with relative standard deviations no more than 50%.The detection limits（LOD） were in the range of 015-035 μg/kg and the quantitative limits（LOQ） were 047-110 μg/kg.The established method has the advantages of high sensitivity，nice selectivity and low detection limit，and was applied in the determination of PGRs in fruits and vegetables with satisfactory results.关键词：Key words：high liquid chromatography-electrospray ionization tandem mass spectrometry（HPLC-ESI-MS/MS）;plant growth retardants（PGRs）;residues
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发布时间： - 摘要：A new nickel（Ⅱ） ion imprinted polymer（IIP） material was synthesized by using bulk polymerization of acrylamide as monomer,divinylbenzene as crosslinking agent，2,2 azobis sobutyronitrile as initiator and methanol as solvent in the presence of nickel（Ⅱ）.The structure of polymer was studied by IR spectrometry.The result indicated that some characteristic groups in the ion imprinted polymer interacted with the template.To get the optimal reaction conditions,the effect of the molar ratio of Ni2+/monomer and monomer/crosslinker,and the volume of solvent on adsorption properties of Ni（Ⅱ） imprinted polymers was investigated.The best adsorption capacity of the polymer adsorbent was obtained when uisng Ni（Ⅱ） functional monomer of 1∶4（molar ratio）,functional monomer-crosslinking agent of 1∶5（molar ratio） and solvent volume of 10 mL.The adsorption and selectivity capacity of nickel（Ⅱ） ion imprinted polymer for Ni（Ⅱ） ion were studied.The results showed that the imprinted polymer had good affinity for Ni2+.The maximum adsorption capacity was 126 mg/g,which corresponded with the saturated adsorption（Qmax） of 135 mg/g.The sorption equilibrium time was 35 min and the optimum pH for quantitative nickel retention was 80.The relatively selective factor（K′） of Ni to other metal ions were greater than 1.The IIP could be repeatedly used with high selectivity and stability for Ni（Ⅱ）.关键词：nickel（Ⅱ）;ion imprinted polymer;selective adsorption
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发布时间： - 摘要：The interactions of lysozyme with ephedrine，pseudoephedrine and methylephedrine，as well as their structure-activity relationship were investigated by fluorescence spectrometry under simulative physiological conditions.The binding constant，the number of binding sites and the thermodynamic parameters were calculated and the effects of ephedrine，pseudoephedrine and methylephedrine on the conformation of lysozyme were studied.The results showed that the endogenous fluorescence of lysozyme was significantly quenched by ephedrine，pseudoephedrine and methylephedrine.The mechanism of fluorescence quenching was static quenching.The 1∶1 complex was formed between each amphetamine and lysozyme.The binding constants K of ephedrine，pseudoephedrine and methylephedrine were 511×103，404×103,280×103 L?mol-1，respectively.According to the theory of Fster dipole-dipole non radiation energy transfer mechanism，the binding distances r were 0241,0350,0422 nm，respectively.The enthalpy change（ΔH）were-123,-126,-521 kJ?mol-1，the entropy change（ΔS） were-329，-339,-103 J?mol-1?K-1，respectively.The results demonstrated that the configuration and substituted methyl in amphetamines played an important role in the interaction between amphetamines with lysozyme，and the order of the interaction strength between the amphetamines and lysozyme was as follows：ephedrine＞pseudoephedrine＞methylephedrine.The hydrogen bond and Vander Waals force were the major driving force between amphetamines and lysozyme.The influences of three amphetamines on the conformation of lysozyme were also investigated with synchronous fluorescence spectra.The result showed that the conformation of lysozyme was not changed by three amphetamines.关键词：ephedrine;pseudoephedrine;methylephedrine;lysozyme;fluorescence spectroscopy;synchronous fluorescence spectroscopy
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发布时间： - 摘要：Protein fluorescent dyes,Cy2,Cy3 and Cy5,were used to label protein samples.The protein integrity expression profile of keratinocytes cell HaCaT stimulated by 2,4 dinitrobenzene sulfonic acid（DNBS) was probed using two dimensional difference in gel electrophoresis（2D-DIGE).And the differentially expressed protein spots were compared and selected.Triplicate samples of protein extracts were used for both the control HaCaT cell and the DNBS treated HaCaT cell.Following the 2D-DIGE,the master DIGE gel was post stained by using Deep Purple protein fluorescent dye.The results indicated that over 1200 protein spots were averagely resolved on each DIGE gel by DeCyder software analysis.846 protein spots were matched for all three gels.And seven protein spots were found differentially expressed with the level above 50% due to the DNBS stimulation with statistically significance（P<005).A proteomic approach,high performance liquid chromatography combined to nano electro spray ionization tandem mass spectrometry（HPLC-nESI-MS/MS) was used for protein identification.The five up regulated protein spots were identified as chromosome X open reading frame 26（Cxorf26),human Co chaperone P23（PTGES3),calmodulin（Calm3),smooth muscle and non muscle myosin alkali light chain 6（MYL6),and breakpoint cluster region protein 1（BANF1).The two down regulated protein spots were identified as transcription elongation factor B polypeptide 2（TCEB2) and RPL23 protein,respectively.Only myosin has been reported to be asso ciated with certain skin disease.Those seven protein candidates identified by current work might provide some useful clues for the risk assessment of skin diseases originated from occupational exposures to chemical carcinogens such as DNBS.关键词：2,4 dinitrobenzene sulfonic acid;occupational exposure;2 dimensional difference in gel electrophoresis;HPLC-nESI MS/MS;HaCaT
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发布时间： - 摘要：A gas chromatography-mass spectrometry（GC-MS） coupled with accelerated solvent extraction（ASE） method was developed for the simultaneous determination of 28 polychlorinated biphenyls,16 polycyclic aromatic hydrocarbons and 21 organochlorine pesticides in marine sediments.The results indicated that the best simultaneous extraction temperature and time were 100 ℃ and 5 min,respectively.Under the optimal conditions,the analysis of 65 compounds were carried out with GC-MS.The calibration curves were linear in the range of 005-500 mg/L for PAHs with correlation coefficients（r2） of 0991-0999 and 50-5000 μg/L for PCBs and OCPs with r2 no less than 0996.The limits of detection of PCBs,PAHs and OCPs were in the range of 003-011,004-073,006-048 μg/kg,and the limits of quantitation were in the range of 011-035,012-242,018-161 μg/kg,respectively.The spiked recoveries ranged from 70% to 146% with RSDs（n=6） of 12%-173% for all the compounds.Through marine sediments standard reference materials,the method was proved to be effective and accurate,and could be applied in the simultaneous determination of 65 compounds in marine sediments.关键词：marine sediments;polychlorinated biphenyls;polycyclic aromatic hydrocarbons;or ganochlorine pesticides;simultaneous determination
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发布时间： - 摘要：Using Sepax Nanofilm SEC 150 chromatographic column and self made narrow distribution polyacrylic acid（PAA） standard sample，effects of different inorganic salts and their ionic strength as well as pH value on the separation of PAA were investigated.The results indicated that the different relative molecular masses of PAA with mass concentration of 05-20 g/L could be separated by using ionic strength of 010 mol/L and pH 69 phosphorous buffer as mobile phase，with a flow rate of 10 mL/min，column temperature of 25 ℃ and sample volume of 50 μL.Under the optimal chromatographic conditions，the relative molecular mass and its distribution of PAA sample were measured accurately by the asymptotic calibration method，and the difference between result of viscometric and GPC methods was less than 10%.关键词：polyacrylic acid;molecular weight;gel permeation chromatography(GPC);non size exclusion effect
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发布时间： - 摘要：A headspace（HS） coupled with gas chromatography-mass spectrometric（GC-MS） method was developed for the determination of 5 residual volatile organic compounds（VOCs）in coating samples. The experimental conditions, such as solvent type, equilibrium temperature and time, as well as the analytical conditions of GC-MS, were optimized. The samples were first dissolved in water-N,N dimethylformamide （1∶1, by volume）and treated at 90 ℃ for 90 min,then separated on a DB VRX capillary column（30 m×025 mm×14 μm），and determined by GC-MS with the external standard method. The results indicated that the recoveries were in the range of 82%-105% with relative standard deviations（RSDs） of 05%-39%. The linear range of 5 VOCs were in the range of 0013 3-667 mg/L with correlation coefficient no less than 0998 9. The limits of quantitation （S/N=10） were no more than 10 mg/kg. The method was used to determine 5 VOCs in 22 kinds of solvent based coating and 31 kinds of waterborne coating samples. The result indicated that the proposed method was simple, accurate, rapid and sensitive and could be applied in the rapid analysis of residual VOCs in various coatings.关键词：headspace gas chromatography-mass spectrometry（HS/GC-MS）;volatile organic compound;coatings
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发布时间： - 摘要：An analytical method was developed for the dertermination of atrazine（ATRZ) metabolites，including deethylatrazine（DEA),deisopropylatrazine（DIA)and didealkylatrazine（DDA)，in urine sample. The samples were added 2 amino 4 methoxyl 6 methyl s triazine（AMMT) as internal standard followed by alkalification,then extracted by solid phase extraction technique using high polar GDX501 porous resin as sorbent and ethyl acetate as elution solvent. The extracts were derivatized with N methy N t butyldimethyltrifluoroacetamide（MTBSTFA) in acetonitrile and analyzed by gas chromatography-mass spectrometry under the selected ion monitoring mode.Without being derivatized in this method condition，ATRZ can also be analyzed by original form. The extraction efficiencies of DEA,DIA，DDA and ATRZ in urine were 80%，78%，71% and 85%，respectively.The detection limits of DEA,DIA,DDA and ATRZ in urine were 02,02,01,1 μg/L,respectively. The calibration curves were linear in the range of 05-100 μg/L for 3 metabolites and 5-1 000 μg/L for ATRZ. The recoveries of 3 metabolites at two concentration levels of 1 μg/L and 50 μg/L were 97%-103% and 98%-101% with RSDs of 92%-117 %and 52%-89%，respectively. The recoveries of ATRZ at two concentration levels of 10 μg/L and 500 μg/L were 101% and 99%with RSDs of 127% and 67%，respectively. The method is sensitive，and could be applied in the analysis of ATRZ and its metabolites in urine samples of human poisoned by ATRZ or occupationaly exposed to ATRZ.关键词：herbicide;atrazine;urine;gas chromatography-mass spectrometery;solid phase extraction;silyl derivatization
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发布时间： - 摘要：A glassy carbon electrode modified with poly lamotrigine film（PLTG/GCE） was fabricated. The poly lamotrigine film was deposited at the glassy carbon electrode by cyclic voltammetry in H2SO4 solution. The electrode was characterized by alternating current（AC） impedance. NO-2 was determined by the differential pulse voltammetry（DPV） using the electrode in KH2PO4 and Na2HPO4 buffer solution. The modified electrode exhibited good electrocatalytic response to the oxidation of nitrite．A good linear relationship was obtained between the anodic peak currents and NO-2 concentrations in the range of 96×10-6-11×10-3 mol?L-1 （correlation coefficient r=0998 8） with a detection limit of 32×10-6 mol?L-1. The proposed method was applied for the determination of NO-2 in real water samples with satisfactory results.关键词：poly lamotrigine film;glassy carbon electrode;NO-2;electrocatalysis
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发布时间： - 摘要：A solid phase extraction/high performance liquid chromatographic method was developed for the analysis of residues of 24 dichlorophenoxyacetic acid(24 D),gibberellic acid(GA3),paclobutrazol(PP333) and 6 benzylaminopurine(6 BA) residues in watermelons. Samples were extracted with 80% methanol water solution,then concentrated and cleaned up on a Strata C18 solid phase column.The separation of target compound was carried out on a ZORBAX Eclipse XDB C18 column (46 mm×150 mm,5 μm) under gradient condition using methano-015% phosphoric acid as mobile phase.The ultraviolet detecter was used to detect analytes at 220 nm.Four plant growth regulaters were qualitatively analyzed by using retention time and UV spectra,and quantitatively determined by the external standard method.Under the optimal conditions,the calibration curves were linear between the peak areas and the concentrations in the range of 05-10 mg/L with correlation coefficients(r) more than 0999.The limits of detection were between 005 mg/kg and 015 mg/kg.The recoveries at two spiked levels of 100 mg/kg and 300 mg/kg ranged from 82% to 90% with relative standard deviations(RSDs) no more than 38%.The results indicated that this method was simple,accurate and sensitive,and was suitable for the analysis of 24 D,GA3,PP333 and 6 BA in fruits.关键词：high performance liquid chromatography(HPLC);solid phase extraction;24 dichlorophenoxyacetic acid;gibberellic acid;paclobutrazol;6 benzylaminopurine;residues
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发布时间： - 摘要：In this paper,the evaluation of moisture，total acid(lactic acid) and amino acid in Fuling mustard tuber by Fourier transform near infrared spectroscopy(FT-NIRS)was studied.The original spectra of 58 calibration samples of Fuling mustard tuber were obtained using FT-NIRS machine,and processed with math analysis such as first derivative,straight line subtraction,multiplicative scattering correction and min-max normalization to decrease the noise.The partial least squares(PLS) calibration models were established under the optimal conditions to predict the content of moisture，total acid(lactic acid) and amino acid.Determination coefficient(R2),root mean square error of cross validation(RMSECV) and root mean square error of prediction(RMSEP) were used to evaluate the quality of the model.The R2 and RMSECV of the model for moisture,total acid and amino acid were 0957 8,0975 4,0950 4,and 0107，0017 1，0036 3,respectively,while the R2 and RMSEP for them three were 0956 2,0953 9,0946 0 and 0256，0034 7，0038 8 in test set validation,respectively.By statistical significance test,the determination results were compared with those of standard methods without significant difference at 005 level.Internal and external cross certification test showed that near infrared quantitative analysis could meet the requirement of prediction of moisture，total acid and amino acid content of Fuling mustard tuber in production with high accuracy.关键词：near infrared spectroscopy;Fuling mustard tuber;moisture;total acid;amino acid
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发布时间： - 摘要：A novel miniature cold vapor generation atomic fluorescence spectrometry was developed using amorphous Teflon AF 2400 tube as the gas-liquid separator and detection cell for the determination of Hg in tobacco,based on the Teflon AF 2400 tube′s excellent gas transport behavior and high UV transparence.The effects of length of Teflon AF 2400,type and concentration of reducing agent,type and concentration of acid medium,flow rate of sample and Ar on the system were investigated in detail.Under the optimal conditions,the calibration curve was linear in the range of 007-10 μg/L with detection limit of 002 μg/L.The relative standard deviation（RSD） was 33% for eleven consecutive measurements of 050 μg/L Hg standard solution.The novel system showed the advantages of micro scale,low sample consumption and high sensitivity.The method was successfully used in the determination of Hg in tobacco sample with recoveries of 97%–102%.关键词：Teflon AF 2400 tube;atomic fluorescence spectrometry;Hg;tobacco
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发布时间： - 摘要：A novel sorption extraction stir bar（SBSE） based on the polymer monolithic material was prepared by in situ stepwise polymerization of epoxy resin（EP） and diethlenetriamine（DETA） using polyethylene glycol（PEG 1540） as porogen. The SBSE was used for the adsorption and extraction for Cd ion in environmental water sample. The experimental conditions such as pH value，stir rate，extraction time，desorption solution and time were optimized. The SBSE operation was performed at a stirring rate of 300 r/min at pH 60 for 30 min，and the desorption was done in 5% HNO3 for 10 min. The concentration of Cd ion was detected by ICP-AES method. The result indicated that the calibration curve showed a good linear relationship in the Cd concentration range of 01-50 mg/L with a correlation coefficient of 0997 2.The relative standard deviation and detection limit(3σ) were 46%and 38 μg?L-1, respectively， and the recoveries ranged from 97% to 104%. The method could be applied to the determination of Cd ion in environmental water samples with good reproducibility and reliability.关键词：stir bar;Cd ion;monolithic material;environmental water
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发布时间： - 摘要：A reversed microemulsion electrokinetic chromatographic（MEEKC） method was developed for the separation of three corticosteroids，including hydrocortisone，prednisone and hydrocortisone acetate by using 1 butyl 3 methylimizolium tetrafluoborate（BMIM-BF4） ionic liquid（IL） as additive.The effects of experimental conditions such as BMIM-BF4 concentration and pH value on separation efficiency were investigated.The optimized conditions were as follows：24% sodium dodecyl sulfate（SDS），66% 1 butanol，05% n octane，35 mmol/L BMIM-BF4，pH 22 20 mmol/L NaH2PO4，an applied voltage of -20 kV and a detection wavelength of 250 nm.Under the optimized conditions，the calibration curves were linear in the range of 5-400,5-400,5-800 mg?L-1 for hydrocortisone，prednisone and hydrocortisone acetate with detection limits（S/N=3） of 09，09,12 mg/L，respectively.The RSDs（n=3） were less than 43%.The average spiked recoveries were 102%，97% and 94%，respectively.The results showed that the resolution of the IL-MEEKC method for the separation of hydrocortisone，prednisone and hydrocortisone acetate was higher than that of the conventional MEEKC method.The proposed method was simple，rapid and effective，and could be used for the quality control of cosmetics.关键词：microemulsion electrokinetic chromatography;corticosteroids;ionic liquid;cosmetics
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发布时间： - 摘要：A new Schiff base compound derived from 1，2，4 triazole was synthesized with a high yield.Potentiometric responses of poly（vinyl） chloride（PVC） electrode based on this ligand as neutral ionophore showed high sensitivity and selectivity towards Hg2+ ion.Effects of different plasticizers and amounts of ion exchanger on the potentiometric response property of Hg2+ selective electrode（Hg2+-ISE） were discussed.The result indicated that，under the optimal membrane composition ［PVC：3270，o NPOE：6539，ionphore：099，ion exchanger：092，（w∶w）］，a good Nernstian response slope of (293±03) mV/dec was obtained for Hg2+ in a wide concentration range of 10×10-6-30×10-4 mol/L with a detection limit of 26×10-7 mol/L Except for silver ion，most of alkali metal，alkaline earth metal and other common transition metal ions didnt interfere the performance of the membrane electrode.The fabricated Hg2+-ISE can be used in a wide pH range of 28-56 with a fast response time of less than 12 s and can be used for 3 month without any obvious change in potentiometric response.The proposed electrode was also successfully applied as indicator electrode in the potentiometric detection of Hg2+ in lab water by standard addition method and the results were confirmed by ICP-MS.关键词：ion selective electrode;mercury ion（Ⅱ）;Schiff base
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发布时间： -
Determination of Amount of the Flumetralin in Total Particulate Matter of Mainstream Cigarette Smoke
摘要：A gas chromatographic method coupled with electron capture detection（GC/ECD） was developed for the determination of flumetralin deliver amount in total particulate matter(TPM) of mainstream cigarette smoke during cigarette smoking. Under the standard conditions，cigarette were smoked to collect the TPM of mainstream cigarette smoke with cambridge filter,and then extracted with acetonitrile. The extracts were cleaned up with the SupelcleanTM ENVITM Carb SPE tubes or the mixed chromatography column，and determined by GC/ECD with the external standard method. The calibration curve was linear for flumetralin in the range of 002-20 mg/L with a limit of detection（LOD） of 914×10-6 g/L. When a spiked level of flumetralin by 30 μg/bag was added,the mean recoveries of flumetralin deliver amount in TPM of mainstream cigarette smoke during smoking ranged from 88% to 93% with relative standard deviations （RSDs） of 15%-28%. The average recoveries of flumetralin from spiked blank sample were in the range of 94%-100% with RSDs of 14%-24%. Compared with the traditional methods，the proposed method was simple，rapid，accurate and environment friendly.Therefore,it was suitable for the determination of flumetralin deliver amount in TPM of mainstream cigarette smoke during smoking.关键词：TPM of mainstream cigarette smoke;SupelcleanTM ENVITM Carb SPE tubes;mixed chromatography column;flumetralin;deliver amount;gas chromatography- 1913
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发布时间： - 摘要：The trace levels of selenium content in black peanuts were determined by graphite furnace atomic absorption spectrometry（GF AAS）. The sample was ingested with high pressure closed vessel using nitric acid-hydrogen peroxide as solvent. Pd（NO3）2+Mg（NO3）2 were selected as chemical modifiers to increase the thermostability of selenium, and the pyrolysis temperature and the atomization temperature for the experiments were seted at 500 ℃ and 2 000 ℃, respectively. Under the optimal conditions, the calibration curve showed a good linear relationship between the adsorption peak area and selenium concentration in the range of 10-200 μg?L-1 with a detection limit（3σ） of 878 μg?L-1.The relative standard deviation（n=11） of blank sample was 46%, and the recoveries varied from 96% to 113%. The result also indicated that the kernels and coats of black peanuts contained trace selenium and their contents were higher than those of other two local peanuts.关键词：graphite furnace atomic absorption spectrometry;black peanut;selenium
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发布时间： - 摘要：A high performance liquid chromatographic method was developed for the simultaneous separation and determination of vanillin and o vanillin. Influences of mobile phase composition and column temperature on the separation were investigated. Under the condition of 5% acetic acid-acetonitrile （60∶40,by volume） as mobile phase at a flow rate of 10 mL/min and 25 ℃,the vanillin and o vanillin were separated in less than 5 min. The calibration curves of vanillin and o vanillin showed good linearities in the range of 10-240 mg/L with both correlation coefficients of 0999 7. The limits of detection（S/N=3） for vanillin and o vanillin were 006 mg/L and 002 mg/L,respectively. The average recoveries at three spiked levels were in the range of 99% -102% with relative standard deviations of 02% - 06%. The method was successfully used for the determination of vanillin and o vanillin in real samples with satisfactory results.关键词：high performance liquid chromatography;vanillin;o vanillin;isomers
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发布时间： - 摘要：Using self constructed electrochemical detection system，buddleoside was detected by high performance capillary electrophoresis(HPCE).Several parameters affecting the determination were studied，including effects of potential of working electrode，organic concentration,running buffer，acidity and working voltage.Under the optimal conditions，a linear relationship between the peak height（Y） and the mass concentration（c） was obtained in the range of 20-80 mg/L with a correlation coefficient of 0999 6.The determination limit was 02 mg/L and the average recovery was 99%.关键词：capillary electrophoresis;buddleoside;amperometric detection
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发布时间： - 摘要：A method for the determination of Al，Si，V in residual fuel oil was developed by DUO-ICP-AES with microwave ashing technology.The operative conditions of DUO-ICP-AES were optimized.Under the optimal conditions，the calibration curve was linear in the range of 0-250 mg/L with correlation coefficients（r） of 0999 70-0999 99.The detection limits ranged from 0005 mg/L to 0050 mg/L.The spiked recoveries were in the range of 88%-97% with RSDs of 10%-35%.The method was simple and rapid，and could be applied in the routine analysis of Al，Si，V in residual fuel oil.关键词：DUO-ICP-AES;microwave ashing;residual fuel oil
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