最新刊期
卷 34 ， 期 12 ， 2015
- 摘要：A comparison was made among three versions of QuEChERS sample preparation methods for the extraction of 15 triazole pesticides in fruits.The three QuEChERS methods were the original method without buffer,the AOAC Official Method 2007.01 with acetate buffer,and the CEN 15662 Method with citrate buffer.The clean-up effects of primary secondary amine（PSA） sorbent and C18 sorbent on 15 triazole pesticides were studied.The addition method after extraction was used to evaluate the matrix effects of triazole pesticide in matrix of apple,pear,peach,grape,cherry,banana and orange during gel permeation chromatography coupled to gas chromatography-mass spectrometry（GPC/GC-MS） analysis.As a result,the QuEChERS method without buffer gave good recoveries for 15 triazole pesticides. The cleaning up effect of PSA plus C18 is superior to that of C18 or PSA sorbent.The matrix effects were intensive in the 7 kinds of fruits.In this article,15 triazole pesticides were extracted by the QuEChERS method without buffer,and analysed by using matrix-matched standard calibration as the external standard method with gas chromatography-mass spectrometry in selective ion monitoring（SIM） mode.Moreover,a large volume of sample was allowed to be injected using the program of GPC programmed temperature vaporizer of gas chromatography to improve the sensitivity of measurements.The recoveries of 15 residues in 7 matrixes at three spiked levels of 20,50,100μg/kg ranged from 85.7% to 120.1% with relative standard deviations of 0.2%-11.5%.The calibration curves were linear（r＞0.998） in the range of 10-400μg/L for all the pesticides.The limits of detection（LOD） for the pesticides in fruits ranged from 0.9μg/kg to 9.5μg/kg.Based on these results,the analytical method was proved to be highly efficient,robust and sensitive,and was suitable for monitoring 15 triazole pesticides residues in fruits.关键词：QuEChERS;online gel permeation chromatography/gas chromatography-mass spectrometry（GPC/GC-MS）;triazole pesticides;matrix effects;fruits
- 2148
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- 4
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- 9
发布时间： - 摘要：A poly（6-thioguanine-co-o-aminobenzene sulfonic acid）（P6-TG-ABSA） film modified glassy carbon electrode（GCE）（P6-TG-ABSA/GCE） was fabricated by electrochemical copolymerization of 6-thioguanine（TG） and o-aminobenzene sulfonic acid（ABSA）.The surface morphology and electrochemical activity of the modified electrode were investigated by scanning electron microscopy（SEM） and electrochemical methods.The SEM images show that the copolymer film exhibits a granular surface structure with regular and homogeneous particles，which is helpful to the electro-catalytic oxidation of the analytes.The results of cyclic voltammetry（CV） and differential pulse voltammetry（DPV） show that the modified electrode exhibits strong electro-catalytic activities toward the oxidation of ascorbic acid（AA） and dopamine（DA） in 0.1mol?L-1 phosphate buffer solution（PBS，pH 5.0）.Compared with those at P6-TG/GCE and PABSA/GCE，the current responses in anodic peak signal remarkably increase and the peak potential separation is 0.20V at P6-TG-ABSA/GCE，which could be used for the simultaneous determination of AA and DA mixture with high sensitivity.Under the optimum conditions，the linear dependences of DPV current responses for AA and DA are observed in the concentration ranges of 2-5000μmol?L-1 and 2-180μmol?L-1,with correlation coefficients of 0.9998 and 0.9997，respectively.The detection limits（S/N=3） of AA and DA are 0.06μmol?L-1 and 0.05 μmol?L-1,respectively.The different electrochemical behaviors of AA and DA at P6-TG-ABSA/GCE at various scan rates indicate that the electrode reaction of AA is a diffusion-controlled process,and that of DA is an adsorption-controlled process.The P6-TG-ABSA/GCE is applied in the simultaneous determination of AA and DA concentrations in human urine samples with satisfactory results.关键词：6-thioguanine;o-aminobenzene sulfonic acid;ascorbic acid;dopamine;modified electrode;electrochemistry
- 1945
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- 1396
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- 2
发布时间： - 摘要：An approach was presented for the preparation of 3D nitrogen-doped graphene（3D rGO-DA） using dopamine（DA） as both reductant and functionalizing agents. Compared with reduced graphene oxide（rGO）,the 3D rGO-DA shows an excellent absorption ability toward Pb2+ and Cd2+.The adsorption capacities of 3D rGO-DA toward Pb2+ and Cd2+ were found to be 91.4mg/g and 43.5mg/g,respectively.The effect factors,including adsorption times, pH values and initial concentrations of Pb2+ and Cd2+,were studied. Adsorption time of 120min and pH 5.0 was found to be the suitable condition for Pb2+ and Cd2+ adsorption. The removal efficiency of Pb2+ and Cd2+ reached maximum value of 100% and 87.7% at the initial concentration lower than 30μg/mL, respectively. After 3 cycle absorption/desorption,the 3D rGO-DA still remained an excellent absorptive capacity,and could be easily removed from water with HCl after adsorption process, indicating its applicability in the water purification.关键词：3D graphene;Pb2+;Cd2+;nitrogen-doped
- 2108
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- 1252
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- 1
发布时间： - 摘要：A novel method was developed for the determination of deltamethrin in air by pretreatment of membrane adsorption combined with ultrasound-assisted dispersive liquid-liquid microextraction and high performance liquid chromatography（HPLC）.The analyte was extracted with methanol-water（1∶4） solution,followed by microextraction with chloroform.After ultrasonic dispersion and centrifugation,the sedimentary facies were determined by HPLC.Deltamethrin had a good linearity in the range of 5-1000μg/L.The correlation coefficient was 0.9998 and the enrichment factor was up to 520.The average recoveries of deltamethrin from air sample at spiked levels of 10,50,100μg/L ranged from 78.6% to 106.7%,with relative standard deviations（RSDs） of 2.2%-4.3%.The limit of detection was 1μg/L,and the minimum concentration of detection was 0.04μg/m3.With the advantages of simplicity,accuracy,high extraction efficiency and low consumption of organic solvent,this method was suitable for the determination of deltamethrin in air.关键词：dispersive liquid-liquid microextraction;high performance liquid chromatography（HPLC）;deltamethrin;air;membrane adsorption;ultrasound
- 1937
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- 1021
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- 4
发布时间： - 摘要：An analytical method for the qualitative and quantitative analyses of fipronil and its metabolites residues in fresh jujube was developed by using low temperature liquid-liquid extraction and ultra high liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）. The fresh jujube sample was extracted with acetonitrile，followed by liquid-liquid extraction at -25 ℃. The analysis of fipronil and its metabolites was performed under negative ion mode and multiple reaction monitoring(MRM),quantified by the external standard method. Under the optimized conditions，the fipronil and its metabolites showed good linearities in the range of 0.02 - 10 μg/L，with correlation coefficients(r2) higher than 0.999. The limits of detection of the method were in the range of 0.005-0.02 μg/kg. The average recoveries of fipronil and its metabolites in fresh jujube matrices were in the range of 78.5%-95.8% with relative standard deviations of 3.4%-6.9%. The method is simple and highly sensitive，and is suitable for the rapid determination of fipronil and its metabolites in fresh jujube.关键词：low temperature liquid-liquid extraction;ultra high liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）;fresh jujube;fipronil and its metabolites
- 2004
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- 1101
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- 11
发布时间： - 摘要：A method was developed for the simultaneous determination of phenanthrene(Phe)and 2-ethylphenanthrene(2-EP) in water by synchronous fluorescence spectroscopy combined with artificial neural network(ANN) and support vector regression(SVR).The characteristic wavelength offset(Δλ)is 118 nm by adopting three dimensional synchronous fluorescence spectroscopy with parallel factor analysis(PARAFAC).In range of 220-280 nm,the fluorescence intensities at 31 wavelengths were regarded as input variables for ANN and SVR models analysis.The results showed that the recoveries of Phe and 2-EP prediction samples were in the ranges of 92.5%-104.9%and 96.1%-104.3%,respectively,obtained by ANN model,while the recoveries of Phe and 2-EP were 98.2%-101.3%and 94.9%-104.2%,respectively by utilizing SVR model.The prediction root mean square errors(RMSEP)of Phe and 2-EP were 2.08 and 2.95 with ANN model,meanwhile they were 0.74 and 2.42 with SVR model,respectively.Recovery experiments by standard addition in actual water samples demonstrated that a satisfactory result was obtained with the two models for mineral water(simple matrix).However,predictive values were lower than the actual values for lake water(complex matrix),in which the performance of SVR model was more steady,and had stronger generalization ability than ANN model.Moreover,the synchronous fluorescence spectroscopy coupled with SVR was used to simultaneously calculate the binding coefficients of Phe and 2-EP with humic acid(HA)in a mixture solution.The result showed that the bonding capabilities of Phe and 2-EP in the mixed systems are both less than those in single component system,which indicated that there is a competing absorption existing between Phe and 2-EP.
- 2000
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- 1165
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- 1
发布时间： - 摘要：A liquid chromatography-tandem mass spectrometric method（LC-MS/MS） was developed for the determination of content of vitamin A,vitamin D2，vitamin D3，vitamin E and vitamin K1 in infant formula milk.The fat vitamins were extracted with petroleum ether after enzymatic hydrolysis and saponification.The chromatographic separation was completed with the column of BEH C18（100 mm×2.1 mm,1.7 μm） using methanol（0.02% formic acid）-0.1% formic acid solution as mobile phase.Ionization mode was positive atmospheric pressure chemical ionization（APCI）.Mass spectrometry data was acquired by multiple reaction monitoring（MRM） mode.The quantification analysis was carried out by isotope dilution method（each vitamin had its isotope internal standard）.The calibration curves of 5 fat vitamins were linear in the certain concentration ranges with correlation coefficients（r2） above 0.99.The recoveries at three spiked levels（low,middle and high） ranged from 83.8% to 113.7% with relative standard deviations（RSD,n=6） of 1.2%-10.1%.The quantitation limits were in the range of 0.5-10 μg/100 g.The method was rapid,easy,accurate and sensitive,and could be used to detect fat vitamins in infant formula milk.关键词：isotope dilution;liquid chromatography-tandem mass spectrometry（LC-MS/MS）;fat vitamin;vitamin A;vitamin D;vitamin E;vitamin K1;determination
- 2012
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- 1225
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- 7
发布时间： - 摘要：A method for the determination of 9 organophosphate flame retardants（OPFRs） in water by liquid-liquid extraction（LLE） followed by gas chromatography with flame photometry detection was developed.The main analytical conditions,such as water sample preparation and instrument analysis method,were optimized.Liquid-liquid extraction was selected using methylene chloride as extraction solvent,and organic phosphorus Rtx-OPPesticides 2 special column was chosen as analytical column.Under the optimal conditions,a completed base line separation of 9 OPFRs was obtained within 15 min.9 OPFRs in the concentration range of 1.0-500 ng/mL showed good linear relationship（r2≥0.998）.The method detection limits（MDLs） ranged from 1.0 ng/L to 2.0 ng/L.At spiked concentrations of 5,100, 300 ng/L,the recoveries of 9 OPFRs were in range of 75.9%-111% with relative standard deviations（RSD） of 3.3%-15%.The method was further applied in the determination of OPFRs in real lake water samples with 9 OPFRs total concentrations of 408-1 532 ng/L.The analytical result showed that the lake water was contaminated by OPFRs.关键词：organophosphate flame retardants;liquid-liquid extraction;gas chromatography with flame photometry detection;water samples
- 1959
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- 1037
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- 2
发布时间： - 摘要：An adsorbent,aminated mesoporous silica was synthesizmg via aminopropyl silatrane functionalizing mesoporous silica.The characterization of this adsorbent was investigated by transmission electron microscopy（TEM） and fourier transform infrared spectroscopy（FT-IR）.A new method was developed for the determinaon of trace cadmium by flame atomic absorption spectrometry（FAAS） after separation/preconcentration with the aminated mesoporous silica material as adsorbent.The influencies of various analytical parameters on cadmium extraction,such as pH value,flow rate of sample,type and amount of eluent,adsorption capacity of adsorbent and interfering ions were investigated.The results indicated that cadmium could be well absorbed at pH 7.0 and a sample flow rate of 8 mL/min.After adsorption,Cd（Ⅱ） was eluented with 5.0 mL 2.0 mol/L HNO3,and determined by FAAS.The linear range of Cd（Ⅱ） ranged from 0.6 ng/mL to 20 ng/mL.The limits of quantitation（LOQ） was 0.5 ng/mL,and the enrichment factor for the present method was obtained to be 50.The RSD（n=11） for 10 ng/mL Cd（Ⅱ） standard solution was 0.92%.The spiked recoveries of Cd（Ⅱ） were in the range of 98.8%-104.5%.The modified mesoporous silica demonstrated an excellent anti-interference capacity,and the adsorption/desorption process remained effective for at least twelve consecutive cycles.The method was applicable for the determination of trace Cd（Ⅱ） in environmental water samples with satisfactory results．关键词：aminated mesoporous silica;separation/preconcentration;flame atomic absorption spectrometry;cadmium
- 1955
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- 1123
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- 4
发布时间： - 摘要：A GC/ECD method was developed and validated for the simultaneous analysis of clofentezine,bromopropylate,chlorfenapyr,and pyridaben residues in apple and citrus.The apple and citrus samples were extracted with acetonitrile,and purified by QuEChERS method using C18 and MgSO4 as adsorbents,then determined by GC/ECD and quantified by the matrix-matched standards solution.The result showed that the calibration curves were linear in the ranges of 0.02-2.0 mg/L for clofentezine and pyridaben,and 0.004-0.5 mg/L for bromopropylate and chlorfenapyr,with correlation coefficients more than 0.99.The limits of quantitation（LOQs） for four acaricides were between 0.001 mg/kg and 0.02 mg/kg.The average recoveries（n=6） of the four analytes in apple and citrus at three spiked levels were between 76.4% and 111.8% with RSDs not more than 13.4%.This method is simple,rapid,effective and safe,and could meet the requirements for the simultaneous-determination of clofentezine,bromopropylate,chlorfenapyr and pyridaben residues in apple and citrus samples．关键词：QuEChERS;GC/ECD;apple;citrus;acaricide;residue analysis
- 1946
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- 1118
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- 4
发布时间： - 摘要：The unfolding processes of two hemoproteins including hemoglobin（Hb） and cytochrome c（Cyt c） were investigated by using UV-Vis absorption and fluorescence emission spectrometry.The unfolding behaviors of Hb and Cyt c were induced with two chemical denaturing agents of guanidine hydrochloride（GdHCl） and urea.Weak bonding energy between heme groups and the histidine on Hb peptide caused the poor stability of heme groups and their easier dissociation from the peptide of Hb only in 3.0 mol/L GdHCl.However,high bonding force due to the disulfide bond between heme group and cysteines on Cyt c peptide chain increased the stability of Cyt c.Heme group did not dissociate from Cyt c peptide with high concentration of 6.0 mol/L GdHCl.The research provides an important basis for the elaboration of relationship between protein functions and their conformations.关键词：hemoglobin;cytochrome c;protein;unfolding
- 2046
- |
- 1114
- |
- 1
发布时间： - 摘要：A new method was developed for the determination of glycyrrhizic acid in cigarette by high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）.The samples were extracted with methnol-5 mmol/L NH4Ac（4∶1） under oscillation,then separated on an Agilent ZORBAX Eclipse XDB-C18 column（2.1 mm×150 mm，3.5 μm）.The glycyrrhizic acid was detected with HPLC-MS/MS under multiple reaction monitoring（MRM） mode,and quantified by the external standard method.The method had a good linearity（r2>0.999） in the concentration range of 0.05-2.50 mg/L.The recoveries of glycyrrhizic acid were in the range of 89.1%-105.0% with intra-day and inter-day relative standard deviations both not more than 5%.The limit of quantitation（LOQ） of method was 4.8 mg/kg.关键词：high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）;cigarette;glycyrrhizic acid
- 2294
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- 1142
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- 1
发布时间： - 摘要：New molecularly imprinted polymers（MIPs） were prepared by using attapulgite（ATP） as the support,β-CD and methacrylic acid（MAA） as functional monomer,resveratrol as template molecule through surface molecularly imprinted polymerization technology.The MIPs were used as sorbent filled into the multiplug filtration clean-up（m-PFC） column for resveratrol enrichment and purification.A new method was developed for the determination of resveratrol by using multiplug filtration clean-up column with molecularly imprinted polymers extraction（MIPs-m-PFCE） combined with fluorescence spectrometry.The results showed that the present method has a high selectivity for RES under the optimized experimental conditions,the adsorption capacity of MIPs was 12.78 mg/g.The calibration curve was linear in the range of 0.1-100 μg/mL with a correlation coefficient（r） of 0.999 7.The limit of detection was 0.048 μg/L.The proposed method was successfully applied in the determination of RES in peanut root,with average recoveries of 86.2%-102.1% and relative standard deviations（RSDs） of 3.5%-5.8% at three spiked levels.The developed method is rapid and selective,and is adaptable to the analysis of trace RES in real samples.关键词：resveratrol;molecular imprinted polymers;multiplug filtration clean-up column;molecular fluorescence spectrometry;peanut root
- 2272
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- 1259
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- 6
发布时间： - 摘要：The method for quantitative analysis and depth profile analysis of Cu（In,Ga）Se2（CIGS） solar cell films was established using X-ray photoelectron spectroscopy（XPS） based on international key comparison K129 participated by National Institute of Metrology（NIM）.The depth sputtering and spectrum acquisition were carried out by using suitable conditions which were obtained through pre-research.The data analysis processes included determination of signal intensity using total number method,determination of relative sensitivity factor,atomic fraction and uncertainty.By using the data processing,a reliable and effective film composition could be obtained.The results indicated this method had a good repeatability with RSD less than 2% in 5 measurements.The atomic fractions of Cu,In,Ga and Se were measured accurately with expand uncertainties less than 4%,which was consistent with those obtained by other national metrology lab.In addition,the analytical result calculated from 4 different sensitivity factors which were obtained from reference sample and instrumental database were compared.The results showed that the values of sensitivity factors from instrumental database modified by the manufacturer were closer to the values obtained from the reference sample,thus the sensitivity factors from instrumental database modified by the manufacturer could be used for the quantitative analysis of atomic composition of alloy films with XPS.The method could be used for the composition measurement of a lot of films with accurate improvement with surface analytical techniques.关键词：CIGS film;surface analysis;depth profile;X-ray photoelectron spectroscopy（XPS）;international key comparison
- 1961
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- 1266
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- 0
发布时间： - 摘要：A simple and rapid capillary zone electrophoresis method was developed for charge variants determination of anti-epidermal growth factor receptor(EGFR) antibody.To obtain better resolution of antibody charge variants and less analysis time，a number of separation parameters were investigated，including concentration and pH value of separation buffer，concentration of additives，separation voltage and temperature of capillary.The optimized conditions were as follows: separation buffer:pH 6.0 380 mmol?L-1 6-aminocaproic acid(EACA) containing 0.1% hydroxypropyl methyl cellulose(HPMC) and 1.9 mmol?L-1 triethylenetetramine(TETA)；applied separation voltage:25 kV；capillary temperature: 20 ℃.Under the optimized conditions，the highest resolution was obtained among all the charge variants in 8 min.Meanwhile，all the components，including the main component，acidic variants，basic variants 1 and basic variants 2，were linear in the range of 0.1-1 mg?mL-1 with correlation coefficients more than 0.99.The limit of quantitation for the four charge variants were 30.0，150.2，125.2 ,93.3 μg?L-1，respectively.The method showed a good repeatability and intermediate precision for all components with RSDs less than 2%，and the recoveries for all the antibody charge variants ranged from 95.4% to 105.4%.This method was simple，rapid and low cost，and could meet the requirement for the determination the charge variants of anti-EGFR antibody.关键词：capillary zone electrophoresis;charge variants;anti-EGFR antibody;additives
- 1939
- |
- 1023
- |
- 1
发布时间： - 摘要：Through inventory modeling and calculating,three kinds of chemical analytical method for the determination of total iron content in iron ores(acid dissolution method,alkali fusion method and microwave digestion method) were assessed and compared in the respects of human health,ecosystem quality,climate change and resource consumption by means of life cycle assessment(LCA)software SimaPro7 and assessment mode IMPACT 2002+(IMPact Assessment of Chemical Toxics).With the assessment of three methods,it is found that human health,climate change and resource consumption are the main impacts on the environment.The single score assessment of life cycle of the above chemical analysis procedures were calculated and the results are 1.97,1.81,0.07 mPt for the alkali fusion method,acid dissolution method and microwave digestion method,respectively.The environmental impacts of alkali fusion method and acid dissolution method are respectively 28 times and 26 times of that of microwave digestion method.For human health hazard,the single score assessments of the alkali fusion method,acid dissolution method and microwave digestion method are 1.15,1.07,0.039 6 mPt,respectively.The carbon footprints for the alkali fusion method,acid dissolution method and microwave digestion are 5.12,4.62,0.189 kg CO2 eq,respectively.It suggests that the emissions of microwave digestion method are the minimum and it could be called the most environmental friendly method.Compared to the alkali fusion method and the acid dissolution method,microwave digestion method obviously has more advantages,and is worth to be recommended as the best chemical analytical method.关键词：chemical analytical method;life cycle assessment(LCA);iron ores
- 1925
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- 1086
- |
- 0
发布时间： - 摘要：An ion chromatographic method was developed for the determination of trifluoroacetic acid（TFA） residues in linagliptin drugs.After dissolved with dichlomethane and extracted with water，the samples were loaded onto the instument.The determination was performed on an Ionpac AS11-HC（4 mm×25 cm） column with an IonpacAG11-HC（4 mm×5 cm） guard column.The eluent was 20 mmol/L potassium hydroxide solution produced on-line with EGⅢ KOH at a flow rate of 12 mL/min.TFA was detected by suppressed conductivity with an ASRS 500-4 mm suppressor at a current of 60 mA.The column temperature was set at 30 ℃ and the injection volume was 25 μL.There was a good resolution between trifluoroacetic acid and other components.The calibration curve showed a good linearity（r=0.999 4） in the range of 0.848-6.46 μg/mL.The limit of detection（LOD） was 0.031 8 μg/mL and the limit of quantitation（LOQ） was 0.106 μg/mL.The method has the advantages of simple operation,high sensitivity and good reproducibility,and could be used for the detection of trifluoroacetic acid（TFA） residues in linagliptin drugs.关键词：ion chromatography with direct conductance;trifluoroacetic acid（TFA）;linagliptin
- 1945
- |
- 3
- |
- 3
发布时间： - 摘要：A method was developed for the determination of azodicarbonamide(ADA) in flour products using dansyl chloride(DNS-Cl) precolumn derivatization combined with high performance liquid chromatography-fluorescence detector.ADA in flour products was hydrolyzed by wet heat processing and formed semicarbazide(SEM) finally.SEM was derivatized with DNS-Cl.The derivatization product was separated on an Aglient TC C18 column(250 mm× 4.6 mm,5 μm) using acetonitrile-water(65∶35) as mobile phase at a flow rate of 1.0 mL/min.The oven temperature was set at 30 ℃，the excitation wavelength was 330 nm and the detection wavelength was 530 nm.Under the optimal conditions,the linear range for ADA was in the range of 0.1-50 mg/L with correlation coefficient(r) higher than 0.998.The limits of detection(LOD)and limits of quantitation(LOQ) for the method were 0.03 mg/L and 0.10 mg/L,respectively.The spiked recoveries of ADA at three levels of 0.1,0.3,1.0 mg/kg ranged from 78.4%to 96.6%with RSDs of 7.1%-9.4%.With advantages of simplicity,rapidness and sensitivivity,the method was successfully applied in the analysis of ADA in flour products.关键词：precolumn derivatization;high performance liquid chromatography-fluorescence detector;azodicarbonamide(ADA);dansyl chloride
- 2052
- |
- 1005
- |
- 4
发布时间： - 摘要：A label-free method was developed for the detection of kanamycin using gold nanoparticles(GNPs).This method was based on the fact that aptamer can make GNPs maintain monodispersed in NaCl solution and keep red color.After adding kanamycin into the solution,due to the specific interaction of aptamers with kanamycin,the stability of GNPs was reduced as the aptamer was firstly interacted with kanamycin and removed from GNPs,which induced GNPs aggregating in the presence of NaCl,and the color of the solution was changed into blue or blue-violet,correspondingly.According to the absorbance change of the solution at 630 nm,the content of kanamycin could be rapidly detected using a simple microplate reader with fixed wavelength.The linear range of kanamycin was in the range of 1-10 nmol/L,with a detection limit of 1 nmol/L.The detection process could be accomplished in 5 min.This method could be used to detect kanamycin in milk samples,with advantages of good selectivity and high sensitivity,and is of great significance to detect the excessive antibiotics addition in food.关键词：kanamycin;gold nanoparticle;aptamer;milk
- 1887
- |
- 1178
- |
- 3
发布时间： - 摘要：Sample pretreatment is an important step in chemical analysis.Especially in environmental analysis,sample pretreatment is usually the bottle-neck step due to the complex matrices of environmental samples and the extremely low concentrations of pollutants.Development of novel sorbent materials is an important approach to solve this problem.Microporous organic polymers（MOPs）,ordered mesoporous silica（OMS）,metal-organic frameworks（MOFs）,molecularly imprinted polymers（MIPs）,carbon nanotubes（CNTs） and graphene possess the advantages of low framework density,large surface area,tunable pore size and structure,excellent chemical and physical stability,which have shown a great potential in the field of sample pretreatment techniques.In this paper,the preparation and progresses on the applications of these new nano-materials in sample pretreatments such as solid-phase extraction, dispersive solid phase extraction, solid phase microextraction,stir rod adsorptive extraction,matrix solid phase dispersion,etc,are reviewed,which could provide consultations on applications of new nano-materials in sample pretreatments to complex and trace samples.关键词：materials;sample pretreatment;applications;progress;review20
- 1907
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- 1075
- |
- 5
发布时间： - 摘要：Chiral ligand exchange chromatography is a kind of technique which combines ligand exchange principle with chromatography.The development of chiral ligand exchange strategy has extended the applications of high performance liquid chromatography,electrophoresis and high speed counter current chromatography.This method provides an effective way for the enantioseparation of racemates which are difficult to be enantioseparated by other methods.Applications of chiral ligand exchange in liquid chromatography,electrophoresis and high speed counter current chromatography are summarized.The basic principle，effecting factors,advantages and disadvantages of chiral ligand exchange chromatography are systematically reviewed.Finally,the development trends of chiral ligand exchange chromatography are proposed.关键词：chiral ligand exchange;liquid chromatography;electrophoresis;high speed counter current chromatography;research progress;review
- 1981
- |
- 991
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- 1
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