最新刊期
卷 31 ， 期 11 ， 2012
- 摘要：A method for the determination of furfural,5-methylfurfural and 5-hydroxymethylfurfural in condimen by gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed.In this paper,the conditions for sample pretreatment and GC-MS/MS were investigated and optimized.The samples were extracted with ethyl acetate.The detection was carried out by GC-MS/MS under the multiple-reaction monitoring(MRM) mode.Good linear relationships were obtained in the concentration range of 0.001-20 mg/L of three analytes,with correlation coefficients of 0.999 0-0.999 5.The limits of detections(S/N=3) of three compounds were all 0.005 mg/kg,and the recoveries ranged from 86% to 95%.This method showed the advantages of simplicity,rapidness and low solvent consumption,and the complex matrix disturbance in condimen samples could be eliminated when MRM mode was adopted.关键词：gas chromatography-tandem mass spectrometry(GC-MS/MS);condimen;furfural;5-methylfurfural;5-hydroxymethylfurfural;multiple-reaction monitoring(MRM)
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发布时间： - 摘要：A stable phospholipid bilayer membrane was constructed on Au electrode surface by using a headgroup modified phospholipid and applied as a biomembrane model to investigate the interaction of an antibiotic polymyxin B with phosphatidylserine.Polymyxin B interacted with phosphatidylserine and destroyed the bilayer structure，resulting in increasing membrane permeation.The extent of interaction was dependent on polymyxin B concentration，reaction time and presence of cholesterol.The destroyed bilayer membrane could undergo self-recovery to some extent in KCl solution and the self-recovery was dependent on recovery time and concentration of polymyxin B.In addition，the interactions between PMB and different phospholipids were compared.Headgroup，alkyl chain length and saturation of phospholipid all affected the interaction.关键词：polymyxin B;phospholipid bilayer membrane;phosphatidylserine;cyclic voltammetry;interaction
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发布时间： - 摘要：A method was established for the determination of chlordimeform and its metabolite 4-chloro-2-methylaniline residues in foods of animal by GC-MS.Five kinds of foods derived from animal(e.g.tilapia muscle,chicken liver,pork,shrimp and beef ) were extracted with ethyl acetate in alkaline conditions(pH≥11.0).The extracts were purified with the graphitization carbon black cartridge(GCB SPE，250 mg/3 mL) and neutral alumina solid phase cartridge(Al2O3 SPE，2.0 g/3 mL),and then determined by GC-MS.Good linear relationships were obtained between the peak areas and the concentrations of chlordimeform and its metabolite 4-chloro-2-methylaniline within the range of 10-500 μg/L,with correlation coefficients of 0.999 1 and 0.998 7,respectively.The recoveries were in the ranges of 81%-119% for chlordimeform,and 80%-119% for 4-chloro-2-methylaniline,with RSDs(n=6) of 1.1%-11.7% and 2.0%-13.7%,respectively.The results showed that the quantitation limits for the two compounds were both 10.0 μg/kg.The proposed method was accurate,sensitive and high-efficient,and was applicable in the determination of chlordimeform and its metabolite in animal derived foods.关键词：chlordimeform;4-chloro-2-methylaniline;gas chromatography mass spectrometry(GC-MS);animal derived foods
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发布时间： - 摘要：In order to get reliable results,the measurement parameters of low field NMR(LF-NMR) should be optimized.In this paper,effects of instrument parameter,temperature and volume of the sample on the stability and reproducibility of the results were investigated,by using soybean oil as the object.The results indicated that good stability and reproducibility can be guaranteed if the following parameters such as TR=2 000 ms,τ=200 μs,EchoCount=5 000,NS=4,TD=500 050 and SW=250 kHz are chosen.Before the measurement,a sample of 2.5 mL should be stabilized at 32 ℃ for 10 min,and subsequently transferred to the probe and tested after 1 min stabilization.The results can provide appropriate detection conditions for the latter application of LF-NMR technique in the determination of oil quality.关键词：LF-NMR;edible oil;optimal parameters
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发布时间： - 摘要：An approach,including the surface acid oxidation and covalent grafting,was proposed to prepare modified multi-walled carbon nanotubes(MWNTs).Using multi-walled carbon nanotubes as a new type of solid phase extraction column,and a novel method was developed for the simultaneous determination of two phenoxyacid herbicides e.g.MCPA and 2,4-D in agricultural products by using multi-walled carbon nanotubes as solid phase extraction adsorbent coupled with high performance liquid chromatography(HPLC).The experimental conditions,including the surface acid oxidation,covalent grafting,SPE column operations and chromatography conditions,were optimized.Under the optimal conditions,the method provided a wide linear range for 2 phenoxyacid herbicides with correlation coefficients of 0.998 4-0.999 5,and the detection limit was 0.020 mg/L.The method was applied to detect the residues of phenoxyacid herbicides in soybean,rice and tea.The spiked recoveries for the samples at three spiked concentration levels of 0.20,5.0 and 50 mg/L were in the range of 81%-105 % with RSDs of 3.2%-8.3 %.The results indicated that using multi-walled carbon nanotubes as solid phase extraction adsorbent was efficient for the purification of the agricultural products(included soybean,rice and tea ).With the advantages of accuracy and sensitivity,the proposed method could meet the requirements for determination of low pesticide residues in agricultural products,and provide a useful approach for the analysis of trace substance of agricultural products.关键词：modified multi-walled carbon nanotubes;solid phase extraction;HPLC;agricultural products;phenoxyacid herbicide
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发布时间： - 摘要：A quantitative method was established for the determination of Δ9-tetrahydrocannabinol in cannabis using high performance liquid chromatography.Methanol was selected as the solvent to extract tetrahydrocannabinol from cannabis plant or resin.The separation of tetrahydrocannabinol was performed on a Shimadzu ODS-SP column(150 mm×4.6 mm,5 μm) using water-acetonitrile as mobile phase by gradient elution.The primary quantitative wavelength of UV detector was set at 210 nm and the auxiliary one was at 195 nm or 220 nm.Flow rate was set at 1 mL/min,column temperature was 40 ℃ and injection volume was 10 μL.Under the optimal conditions,good linearity was achieved over the range of 0.5-100.0 mg/L,with correlation coefficients(r2) more than 0.999 99.The limit of detection(S/N≥3.3) was 0.12 mg/L and the limit of quantitation(S/N≥10) was 0.40 mg/L.Using this method to detect a cannabis resin sample,the result of uncertainty evaluation on Δ9-tetrahydrocannabinol’s content was 5.32%±0.17% with k value of 2.The result showed that the method was rapid,sensitive and accurate,and was applicable in the quantitative determination of cannabis plant and resin.关键词：liquid chromatography;tetrahydrocannabinol;quantitative
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发布时间： - 摘要：The interaction between amlodipine and bovine serum albumin(BSA) was investigated by a combined spectral and computational approach.The result showed that BSA fluorescence at 342 nm is quenched regularly with the addition of amlodipine,which belongs to the static fluorescence quenching and the binding mechanism is related to the fluorescence resonance energy transfer(FRET).According to Lineweaver-Burk equation,the binding constants between amlodipine and BSA are 1.214×104 L?mol-1(296 K) and 1.662×104 L?mol-1(303 K),respectively.The calculated thermodynamic parameters(ΔH=33.46 kJ?mol-1,ΔS=19122 J?mol-1?K-1) by Van’t Hoff equation showed that hydrophobic interaction plays a major role in the amlodipine-BSA system.The binding of amlodipine and BSA is a spontaneous inter-molecular interaction driven by entropy.Molecular modeling displayed that amlodipine is bound in the large hydrophobic cavity of BSA,which accords well with the result from the spectral experiment.关键词：amlodipine;bovine serum albumin(BSA);fluorescence quenching;ultraviolet absorption spectroscopy;molecular modeling
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发布时间： - 摘要：Organic pollutants in water samples were extracted by liquid-liquid extraction and semi-quantitated by gas chromatography coupled with mass spectrometry(GC-MS) using compound composer software.The results were simultaneously confirmed by GC-MS under selected ion monitoring mode.The mean recoveries ranged from 74% to 102%，except for m-aminophenol，stigmasterol and beta-sitosterol.The retention time deviations ranged from -0.158 to 0.049 min.The deviations of the semi-quantitative results for 1.0 μg spiked water samples ranged from-0.48 to 0.62 μg.Surface water samples collected from rivers and lakes of Nantong，Suzhou and Wuxi City，Jiangsu Province，were screened and determined for organic pollutants using compound composer software without any standard solutions.The results indicated that total of 47 organic pollutants were detected in the water samples，among which 4-methyl-2,6-di-t-butylphenol was of the highest concentration(140 μg?L-1).Phthalate esters(PAEs) and polycyclic aromatic hydrocarbons(PAHs) were commonly found substances.The isomer concentrations of PAEs and PAHs in the surface water samples were in the range of 1.7-48 μg?L-1 and 0.13-9.6 μg?L-1，respectively.According to the Chinese national environmental quality standards for surface water(GB 3838-2002)，the concentrations of PAEs observed in this study were far beyond the restricted values.More attention should be paid on the current status of the total organic pollutants in the investigated waters.关键词：GC-MS;compound composer software;water;organic pollutants;screening;semi-quantitative
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发布时间： - 摘要：A method was developed for the determination of chloramphenicol,thiamphenicol and florfenicol residues in feedstuff by isotope dillution high performance liquid chromatography-tandem mass spectrometry.After homogenization,the samples were extracted with ethyl acetate.After centrifugation,the extract was evaporated to dryness with nitrogen at 45 ℃,and redissolved with 4 mL ultrapure water.The solution was defatted with hexane and cleaned up by C18 solid phase extraction cartridge.The targeted compounds were seperated on an Agilent Eclipse C18(150 mm×4.6 mm，5 μm) column by using methanol-0.1% formic acid as mobile phase.Identification and detection were achieved by electrospray ionization(ESI) under negative mode using multiple reaction monitoring(MRM) mode.The detection limits for the target compounds were all 0.5 μg/L and the quantitation limits were all 1.0 μg/L.The linear range of the target compounds ranged from 0.5 μg/L to 10.0 μg/L with correlation coefficients not less than 0999 0.Recoveries of three compounds were in the range of 78%-107% at the spiked level of 0.5-2.0 μg/kg,with relative standard deviations(RSDs) less than 10%.关键词：isotope dillution;liquid chromatography tandem mass spectrometry(LC-MS/MS);chloramphenicol;thiamphenicol;florfenicol;feedstuff
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发布时间： - 摘要：A molecularly imprinted polymer(MIP) for thiophene was prepared by a molecular imprinting technique.Influential factors on adsorption capability and recognition performance of MIP for thiophene,such as functional monomer,crosslinker types,solvent,molar ratio of template molecule to functional monomer,were investigated.The results showed that the imprinted polymers,prepared at 60 ℃ by using α-methylacrylic acid as functional monomer,ethylene glycol dimethacrylate as crosslinker,chloroform as solvent and 2，2′-azobisisobutyronitrile as the initiator,exhibited good adsorption capacity and recognition performance for thiophene.This study may provide a theoretical basis for deep desulfurization of gasoline to remove sulfur-contained thiophenic compounds.关键词：molecular imprinting technique;thiophene molecularly imprinted polymers;recognition performance;adsorption capacity
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发布时间： - 摘要：An indirect method for the determination of H2S in main stream smoke of cigarette by HPLC with DAD detector was developed.The influence of concectration of zinc acetate on trapping effectiveness of H2S in main stream smoke was investigated.The optimal conditions were using 30 mmol/L zinc acetate-20 mmol/L sodium acetate as trapping reagent system, and 180 mmol/L H2SO4-3 mmol/L N,N-dimethyl-p-phenylenediamine dihydrochloride-10 mmol/L ammonium ferric sulfate as derivation reagent system.The derivative product methylene blue was separated on an Agilent ZORBAX Eclipse XDB-C18(150 mm×4.6 mm,3.5 μm), using a mobile phase composed of methanol-formic acid-water(45∶1∶55) at a flow rate of 0.8 mL/min.DAD wavelength was set at 665 nm.Under the above optimal conditions, the calibration curve was linear in the concentration range of 10.65-532.69 μg/L H2S(0.1-5.0 mg/L for methylene blue) with a correlation coefficient of 0.999 89.The spiked recoveries of S2-were in the range of 96%-98% with relative standard deviations(RSDs) of 2.4%-3.2%.The detection limit(MDL) for H2S in main stream smoke of cigarette was 0.12 μg/cig.The method is simple, rapid and accurate, and could be applied in the determination of H2S in main stream smoke of cigarette.关键词：H2S;methylene blue;HPLC;main stream smoke of cigarette
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发布时间： - 摘要：A chromatographic method was developed for the determination of arabinose,galactose,glucose,sucrose,xylose,mannose and fructose in soy sauce sample using high-performance anion-exchange chromatography coupled with pulsed amperometric detection(HPAEC-PAD).The removal efficiency of the proteins in the soy sauce was evaluated by using 20% lead acetate,5% trichloroacetic acid,15% potassium ferrocyanide or 70% ethanol,respectively.The results indicated that the best sugar recovery was achieved when 70% ethanol was selected as the protein precipitation agent.Effects of column types,column temperature and NaOH concentrations on separation efficiencies of the saccharides were investigated.The optimal conditions were carried out on a Dionex CarboPac PA20 anion-exchange chromatographic column with 0.25 mol/L NaOH-water by gradient eluent at 20 ℃.The detection limits(25 μL injection，S/N=3) ranged from 2.0 μg/L to 8.0 μg/L,with a wide linear range of 0.1-80 mg/L.The relative standard deviations for the soy sauce sample were between 1.4% and 4.0%,and the recoveries of standard addition of the saccharides were in the range of 92%-104%.The method is suitable for the determination of common saccharides in soy sauce samples for with its simplicity,high sensitivity and good reproducibility.关键词：ion chromatography;pulsed amperometric detection;soy sauce;saccharides
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发布时间： - 摘要：A high performance liquid chromatography tandem mass spectrometric (HPLC-MS/MS) method was developed for the determination of nifursol metabolite 3,5-dinitrosalicylic acid hydrazide(DNSAH) residue in animal tissues.The sample was extracted with ethyl acetate after hydrolysised and derivatized,then cleaned up by n-hexane.The condensed sample solution was separated on a reversed-phase column of Thermo Hypersil Gold C18(100 mm×2.1 mm i.d.，1.9 μm)by gradient elution with methanol-water as mobile phase at a flow rate of 0.3 mL/min.The quantitation detection was performed by HPLC-tandem MS using multiple reaction monitoring(MRM) under negative ion electrospray ionization.The calibration curve of DNSAH was linear in the range of 0.5-5.0 μg/kg.The limit of quantitation was 0.5μg/kg.The recoveries at three spiked levels were between 91% and 103% with RSDs(n=6) of 3.7%-13.6%.The method was sensitive and accurate,and could meet the requirements of the domestic and international legislations.Therefore,the method was suitable for the determination and confirmation of residue of nifursol metabolite in animal tissues.关键词：liquid chromatography-tandem mass spectrometry(LC-MS/MS);nifursol;animal tissue;residue
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发布时间： - 摘要：A semiquantitative gas chromatography-mass spectrometric method relative to internal standard was developed for the fingerprinting analysis of bicyclic sesquiterpanes in crude oils.Based on the chromatograms properties,characteristic fragment ions(m/z 123,179,193 and 207) and the calculated retention indices,10 bicyclic sesquiterpanes compounds were identified and the concentration formulas of semiquantitation using the internal standard(d18-decahydronaphthalene) were provided.Bicyclic sesquiterpanes fingerprinting of 9 crude oils collected from Weizhou island，Bohai sea and crude oil from import sources were analyzed.The result revealed the following situation that the total concentrations of bicyclic sesquiterpanes range from 600 μg/g to 8 000 μg/g.The dominating components in all the studied crude oils are C15-sesquiterpane(BS3),C15-sesquiterpane(BS4),C16sesquiterpane(BS8) and 8β(H)-homodrimane(BS10),which account for 60% of total contents of bicyclic sesquiterpanes.The abundances of bicyclic sesquiterpanes in different oils follow an increasing order as Weizhou island > Bohai sea > crude oil from imports G1，G2.The total bicyclic sesquiterpane contents of G3(crude oil of GIRASSOL) and B3(crude oils from Bohai sea) are similar but exhibit different distributions of bicyclic sesquiterpane signatures.Crude oils from different offshore oil platforms in the same block exhibit very similar bicyclic sesquiterpanes signatures;In contrast,oils from different sources have different signatures of both the concentrations and relative distribution patterns of bicyclic sesquiterpanes compounds.Fingerprinting analysis of bicyclic sesquiter-panes in crude oils by semiquantitative method can achieve the identification of different crude oils.关键词：crude oil;bicyclic sesquiterpanes fingerprint;semiquantitative method
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发布时间： - 摘要：A gold nanoparticles modified carbon paste electrode(GNPs/CPE) was prepared,and the electrochemical characteristics of methotrexate(MTX) at GNPs/CPE were studied by cyclic voltammetric method.A novel electrochemical method for the determination of MTX at GNPs/CPE was established and its interaction with herring sperm DNA(hsDNA) was investigated by linear sweep voltammetry(LSV) and square wave voltammetry(SWV).The results indicated that there was a good linear relationship between anodic peak current and MTX concentration in the range of 0.5-10.0 μmol?L-1,and the detection limit(S/N=3) was 0.2 μmol?L-1.The relative standard derivations(n=11) was 4.7% for 3.0 μmol?L-1 MTX.The method was applied in the determination of MTX in the injection samples with satisfactory results.The results also showed that,in the presence of various concentrations of hsDNA,the redox peak potential of methotrexate shifted positively and its peak current was decreased,which indicated that MTX could react with hsDNA and form an electrochemical inactive compound.The binding equilibrium constant and binding ratio were calculated to be 4.6×105 L?μmol-1 and 2∶1,respectively.关键词：methotrexate(MTX);gold nanoparticles modified carbon paste electrode;herring sperm DNA(hsDNA);interaction
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发布时间： - 摘要：Outlier samples often strongly influence the stability of the model in ultraviolet-visible absorption spectroscopy.Eleven outliers were detected and eliminated from 108 Gastrodia elata blume(GEB) samples by the method of PCA-mahalanobis distance.The population was divided into calibration and validation sets in order to perform an external validation.For that purpose,one of each six samples was selected to build up the validation set,and the rest remained as the calibration set.Calibration from the resulting set of Savitzky-Golay smoothing and differentiation was built up a model using simplified partial least squares regression.By extending the number of smoothing point to 3,5,7,…,25,(odd) and polynomial degree to 2,3,4,5,6,including 162 methods from Savitzky-Golay smoothing and differentiation were calculated.The optimal model was selected by the prediction effect.And the derivation order was 2,the polynomial degree was 4,the number of smoothing points was 5,the optimal correlation coefficient(r) reached 0.910 2,the optimal root mean standard of prediction(SEP) reached 0.390 7 g/L.The results indicated that the using of PCA-mahalanobis distance,Savitzky-Golay smoothing and differentiation and SIMPLS,can be effectively applied in the model optimization of ultraviolet-visible spectroscopy in determining Gastrodin in GEB.关键词：mahalanobis distance method;Savitzky-Golay smoothing and differentiation;simplified partial least squares regression(SIMPLS);ultraviolet-visible absorption spectroscopy;Gastrodia elata blume(GEB)
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发布时间： - 摘要：An high performance liquid chromatographic method for the quantitative determination of quercetin-3-O-β-D-glucuronide and quercetin in Polygonum perfoliatum L.was developed.The separation was performed on a Lichrosher 5-C18 column(250 mm × 4.6 mm,5 μm) together with a C18 guard column by gradient elution using methanol-0.05% phosphoric acid as mobile phase at a flow rate of 1 mL/min.The detection wavelength was set at 258 nm and the colume temperature was 25 ℃.Two compounds were successfully separated in 30 min.The calibration curves were linear in the ranges of 0.037 6-3.920 0 mg for quercetin-3-O-β-D-glucuronide and 0.004 2-0.440 0 mg for quercetin.The limits of detection(LOD) and limits of quantitation(LOQ) were 2.509,0.282 ng and 6.272,0.702 ng，respectively.The mean recoveries of two analytes were 99% and 98%,respectively.The established method was applied in the determination of contents of both two compounds in 15 samples obtained from different regions,and the results showed that the proportion of both compounds in different samples were great different.The proposed method is simple,rapid and accurate,and can be used for the quality control of Polygonum perfoliatum L..关键词：Polygonum perfoliatum L.;quercetin-3-O-β-D-glucuronide;quercetin;high performance liquid chromatography
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发布时间： - 摘要：A method for the simultaneous determination of three main keto ageing compounds,such as diacetyl,2,3-pentanedione and β-damascone,in beer by dispersive liquid-liquid microextraction/high performance liquid chromatography was proposed.Derivatization conditions of diacetyl and 2,3-pentanedione and high performance liquid chromatography conditions of the three target components were established.The separation and detection of three keto ageing compounds were performed in 15 min.The conditions of dispersive liquid-liquid microextraction were studied,and the enrichment factors of three compounds were 45,63 and 121,respectively.Good linearities were obtained for three compounds with correlation coefficients of 0.999 6-0.999 9,and the linear range is greater than or equal to 103.The detection limits(S/N=3) were in the range of 0.3-0.9 μg/L.The average recoveries of real samples were in the range of 86%-97% with RSDs of 2.4%-4.8%.关键词：dispersive liquid-liquid microextraction;high performance liquid chromatography;ageing compound;diacetyl;2,3-pentanedione;β-damascone;beer
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发布时间： - 摘要：A headspace/gas chromatography-tandem mass spectrometric(HS/GC-MS/MS) method was established for the determination of 1，4-dioxane residues in synthetic detergents and cosmetics.The samples were mixed with water，then sodium chloride was added to produce the “salting-out” effect.After oscillation，1，4-dioxane in sample was dissolved completely.The sample mixed with water was oscillated for 30 min at 80 ℃ to get gas-liquid balance state and then the upper clear gas was prepared.The detection was carried out by GC-MS/MS under the multiple-reaction monitoring (MRM) mode.Good linearity in the concentration range of 0.1-100 mg/L was obtained，with a correlation coefficient of 0.999 8.The limit of detection(LOD) was 0.010 mg/kg and the limit of quantitation(LOQ) was 0.035 mg/kg.The average recoveries were in the range of 98%-103%，with relative standard deviations(RSDs) of 0.44%-2.1%.The accuracy，reliability and sensitivity of the method made it suitable for the determination of 1，4-dioxane in synthetic detergents and cosmetics.关键词：gas chromatography-tandem mass spectrometry;1,4-dioxane;multiple-reaction monitoring;synthetic detergent;cosmetics
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发布时间： - 摘要：A high performance liquid chromatographic(HPLC) method was developed for the determination of vitamin K1 in cosmetics.Different cosmetic samples were dispersed and extracted by adding saturated sodium chloride aqueous solution and hexane in appropriate sequence,and detected by HPLC with diode array detector(HPLC/DAD).The samples containing high level of waxes were further purified by silica-gel solid phase extraction.The extraction and purification procedures were optimized.Under the optimized conditions,the average recoveries of vitamin K1 were in the range of 99%-105% with relative standard deviations less than 5%.The limit of quantitation was 0.4 mg/kg.The method was accurate,rapid and widely applicable,and could be used to quantitatively analyze vitamin K1 in cosmetics.关键词：cosmetics;vitamin K1;high performance liquid chromatography(HPLC);silica-gel solid phase extraction
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发布时间： - 摘要：Based on a recombinant cell strain for high sensitivity detection of estrogenic activity,estrogen synthesis technology is a revolutionary technology of the detection of the biological efficacy.It has the advantages of high efficiency and high sensitivity characteristic.The HeLa cells(the cells without endogenous hormone receptor) were used to recombine the human estrogen receptor α(hERα) or estrogen receptor β(hERβ),and then build a stable expression of cell to detect the luciferase report gene.pERE-Luc plamid was generated by inserting estrogen response element(ERE) fragment into MCS of pGL3-promoter vector.HeLa cells were cotransfected with pERE-Luc using so fast transfection reagent.The cells were then treated with 17β-estradiol(E2),diethylstilbestrol and progesterone，and expression of the reporter gene in the cell lysates was assayed using Dual-Luciferase reporter assay system.The pERE-Luc plasmid was constructed.Luciferase activities of pERE-Luc-ransfected HeLa cells showed that the correlations between RFU of Luc activity and E2,diethylstilbestrol and progesterone standard sample concentration was nonlinear，r2 was 0.879 8,0.955 0 and 0.926 2,respectively.E2 at 1.0×10-13 mol／L induced the expression of reporter gene and that at 1.0×10-9 mol／L resulted in the peak luciferase activity.Diethylstilbestrol luciferase activity was larger than 1.0×10-10 mol／L and progesterone was larger than 1.0×10-11 mol／L.The estrogenic activity of progesterone was more potent than that of diethylstilbestrol.The averages of the reporter gene emitted were 0.947 4,0.312 3 and 0.579 6,the relative standard deviation were 13.7%,3.7% and 3.4% after treated with E2,diethylstilbestrol and progesterone at 1.0×10-10 mol／L.Results showed that good quality reproducibilities of luciferase reporter gene expression were obtained after treated with E2,diethylstilbestrol and progesterone.The spiked recoveries of E2 were over 75% in four fishes and the relative standard deviations(RSDs) were between 7.3%and 11.6% .The proposed reporter gene-based assay is effective and reliable.关键词：HeLa cells;estrogenic activity;reporter genes;luciferase;aquatic products
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发布时间： - 摘要：A flow injection on-line analyzer for the determination of free chlorine was designed,and the optimal condition was investigated.Based on the improved N,N-diethyl-1,4-phenylenediamine(DPD) colorimetic principle,the analyzer used flow injection sampling technology,combined with photoelectric conversion,digital signal processing and automatic control technology.It could overcome the defects of DPD spectrophotometry done by manual operation，and perform automated sample analysis.The method was proven to consume less reagent with wide linear range(0.05-6.00 mg/L) and lower detection limit(0.019 mg/L).The recoveries were in the range of 90%-98%.The analyzer was apt to be widely used in monitoring free chlorine in the waterworks and water supply networks with rapid sampling frequency(60 h-1) and higher precision(RSD≤1.2%).关键词：free chlorine;flow injection;DPD spectrophotometry;on-line monitor
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发布时间： - 摘要：Conducting polymer could be used as molecular wires for transferring electrons directly between bioactive materials and electrode materials for its good conductivity,and is considered to be a new type of material for fabrication of biological sensors.With some excellent features such as electrical conductivity,biocompatibility and easy immobilization,polypyrrole(PPy)has a good application prospect in the immobilization of bioactive components in sensors.In this paper,the latest research development on biosensors based on PPy is reviewed.The synthesis methods of PPy together with its doping mechanisms were firstly introduced.The various methods for the immobilization of biocomponents on PPy and the fabrications of biosensors based on PPy were described in detail,together with the advantages and disadvantages of the immobilization methods of biocomponents to PPy.Especially,the latest applications of PPy in the field of immunosensors were reviewed.The development direction of conducting PPy biosensors in the future was also put forword.关键词：polypyrrole;biosensor;immobilization methods;immunosensor;review
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