最新刊期
卷 33 ， 期 11 ， 2014
- 摘要：An ultra high performance liquid chromatography-tandem mass spectrometric（UHPLC-MS/MS） method was established for the determination of 10 sedative（azaperol,azaperone,xylazine,haloperidol,promethazine,acepromazine,propionylpromazine,chloropromazine,methaqualone and diazepam） residues in pork,beef and mutton.After enzymolysis,10 veterinary drugs were extracted with acetonitrile and cleaned up with an Oasis MCX SPE column.The analysis of the sedatives were achieved on an ACQUITY UPLC CSH C18 column and detected by electrospray ionization-tandem mass spectrometry in the multiple reaction monitoring（MRM） mode.The calibration curves of ten sedatives showed good linearities（r2≥0.993 6） in the concentration range of 0.5-100 μg/L.The limits of detection（LODs,S/N≥3） were not more than 0.5 μg/kg，and the limits of quantitation（LOQs,S/N≥10） were not more than 1.0 μg/kg.The average recoveries of ten sedatives ranged from 82.0% to 116.0% with relative standard deviations（RSDs） of 0.6%-12.8% at the spiked levels of 1.0,5.0,50.0 μg/kg.The results showed that the method was sensitive,and accurate,and was suitable for the determination of sedative residues in animal originated food．关键词：livestock product;veterinary drug;sedative;residue;ultra high performance liquid chromatography-tandem mass spectrometry（UHPLC-MS/MS）
- 2040
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- 5
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- 9
发布时间： - 摘要：A rapid，sensitive and accurate method was developed for the simultaneous determination of 6 kinds of phthalic acid esters（PAEs）in wine samples by dispersive magnetic solid phase extraction coupled with high performance liquid chromatography（dMSPE/HPLC）.The wine samples were concentrated with polystyrene nano-magnetic materials，then separated on a C8 analytical column（250 mm×4.6 mm×5 μm） using methanol-water as mobile phase by gradient elution，and detected at 230 nm via UV detector.The results showed that，under the optimal condition，good linearities for the target PAEs were obtained between 2 ng/L and 500 ng/L with correlation coefficients（r2） not less than 0.997 9.The spiked recoveries were between 85.2% and 101.2% with relative standard deviations（RSDs） of 0.8%-9.2%.The limits of detection（LODs） were in the range of 0.22-4.5 ng/L and the limits of quantitation（LOQs） were 1.2-10 ng/L.The developed method could be applied in the routine analyses on PAEs in wine samples.关键词：wine samples;phthalic acid esters（PAEs）;polystyrene nano-magnetic materials;dispersive magnetic solid phase extraction（dMSPE）;high performance liquid chromatography（HPLC）
- 2069
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- 1048
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- 5
发布时间： - 摘要：A rapid，simple and sensitive method based on high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS） with an electrospray ionization（ESI） source was presented for the analysis of folic acid in various fortified food products（i.e.juice，rice，liquid infant milk，powder infant milk，biscuit and jelly）.Sensitivity and specificity of this method allowed three important results to be achieved:firstly,developing a rapid sample pretreatment that minimizes the analyte exposition to light，air and heat，eliminating any step of extract concentration and protection by aluminum foil；secondly adding BHT（butylated hydroxytoluene） as antioxidant；Finally,adding methotrexate as the internal standard.Effects of extraction conditions of different matrixes on recoveries were investigated.The sample was separated on a Waters HSS T3 column using methanol-10 mmol/L ammonium acetate（pH 6.3） as mobile phase by gradient elution，and analysed by MS with internal standard under multi-reaction monitoring（MRM） mode via positive electrospray ionization.The method indicated that the calibration curve showed a good linear relationship in the range of 0.05-100 ng/mL，with quantitation limits of 0.01-0.5 mg/kg in different matrixes.The recoveries were in the range of 72.0%-109%，with RSDs of 3.8%-11.8%.With the advantages of easy sample handling，high sensitivity and good precision，the method could meet the requirements for determination of folic acid.关键词：high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）;folic acid;fortified foods
- 2066
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- 985
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- 4
发布时间： - 摘要：Analysis of polysaccharides and their hydrolyzed products in Cassia obtusifolia L.was performed by UV spectrometry and high performance liquid chromatography（HPLC），respectively.The composition characteristics of polysaccharides were developed,including 12 batches of Cassia obtusifolia L.The results showed that the content of polysaccharides extracted from samples were between 93.41% and 98.57% after purification.Under the optimized hydrolysis conditions，monosaccharides obtained were determined by HPLC with 1-phenyl-3-methyl-5-pyrazolone（PMP）derivatization.Based on HPLC data of 12 batches of samples，fingerprints of polysaccharides in Cassia obtusifolia L.were established.Common characteristic peaks were identified as mannose，glucuronic acid，galactosamine，glucose，galactose，xylose and arabinose，and their content was in the range of 1.617-304.5 mg/g.Polysaccharides for 12 batches of Cassia obtusifolia L.basically consisted of seven monosaccharides，named mannose，xylose，galactose，glucose，arabinose，glucuronic acid and galactosamine with an average molar ratio of 43.0∶24.2∶15.4∶5.6∶5.5∶3.4∶2.9.Fingerprints and molar ratio methods were successfully applied in the analysis of medicinal materials sold in market.关键词：Cassia obtusifolia L.;polysaccharide;hydrolysis;monosaccharide;fingerprints;derivatization;high performance liquid chromatography (HPLC)
- 1953
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- 1063
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- 12
发布时间： - 摘要：In this paper,the stability and accuracy of determination method for dichlorvos,phorate,dimethoate,methyl-parathion,malathion,chlorpyrifos and parathion in groundwater were verified by a balanced uniform-level experiment involving five concentration levels and seven laboratories collaboration.Seven organophosphorus pesticides were extracted from groundwater with dichloromethane solution containing about 5% acetone,and the quantitative analysis of organophosphorus pesticides was carried out by gas chromatography with flame photometric detector.The whole analysis processes in every research laboratory and every sample level gave three results for statistics.The presence of individual laboratories or values that appeared to be inconsistent with all other laboratories or values may change the estimates,therefore,decisions have to be made with respect to these values.The balanced uniform-level experiment can provide a deterministic way to prove the accuracies（trueness and precision） of determination method and result by Cochran-test and Grubbs-test methods.The scrutiny of statistical results of seven organophosphorus pesticides in groundwater for consistency and outliers showed that the determination method was stable within a level range of 20-2 000 ng/L after eliminating the outlier data.The average recoveries of determination method for these organophosphorus in different levels were in the range of 91.1%-109% with relative standard deviations of 2.2%-12.6%.The surrogate recoveries for triphenyl phosphate during the analysis process were 77.8%-119%.The detection method is accurate and reliable.关键词：quality evaluation;organophosphorus pesticides;balanced uniform-level experiment;repeatability limit;reproducibility limit
- 1786
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- 1165
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- 0
发布时间： - 摘要：The paper described the determination of n-alkanes in marine sediments by gas chromatography mass spectrometry with accelerated solvent extraction（ASE）for sample pretreatment.The main factors which affect the extraction yield of n-alkanes by ASE，such as proportion of extractant，temperature，static time and cycle times were discussed.The following conclusions were obtained from the study：when the long carbon chain n-alkanes need to be detected or are higher in samples，methanol-methylene chloride（1∶3,by volume）is recommended to used as the extraction solvent.Methanol-methylene chloride（1∶9,by volume）could be used as the extraction solvent while the short carbon chain n alkanes need to be detected or are higher in samples.The quantities of short and long carbon chain n-alkanes and the total n-alkanes gradually increases with increasing of the temperature，static time and number of cycles.The optimum parameters for n-alkanes extraction from marine sediments were as follows：temperature:150 ℃，static time:15 min and cycle times:3 cycles.The RSD of method ranged from 3% to 14%,except for C15 (20%).Alternatives recoveries were in the range of 84%-114%.With the advantages of practicality，reliability，easy operation，low reagent consumption and good precision，the method is suitable for the quantification of marine sediments samples with complicated matrices.关键词：accelerated solvent extraction;n-alkanes;marine sediments
- 1810
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- 1034
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- 1
发布时间： - 摘要：Based on nickel chromium substrate，a novel electochemical sensor was prepared by coating chitosan on the surface of nanotubes modified ultra thin carbon paste electrode（CTS-CNTs-UTCPE），and this sensor was further employed for electrochemical determination of o-，m- and p-nitrophenol.Electrochemical behaviors of o-，m- and p-nitrophenol on CTS-CNTs-UTCPE were investigated by cyclic voltammetry（CV）and semi-differential voltammetry method.Effects of supporting electrolyte，pH value，onset potential，scan rate and accumulation time on the result of detection were explored.Compared to nickel chromium electrode，ultra thin carbon paste electrode（UTCPE）and carbon nanotubes modified ultra thin carbon paste electrode（CNTs-UTCPE），the new electrode displays a larger oxidative current response to o-，m- and p-nitrophenol in pH 5.72 B-R solution，probably due to the synergistic effects between chitosan and carbon nanotubes.Under the optimum conditions，the presented sensor exhibited wide linear responses to o-nitrophenol ranging from 4.0×10-7mol/L to 8.0×10-5 mol/L with a detection limit（S/N=3）down to 2.3×10-7 mol/L，to m-nitrophenol ranging from 4.0×10-7 mol/L to 8.0×10-5 mol/L，with a detection limit down to 2.9×10-7 mol/L，to p-nitrophenol ranging from 8.0×10-7 to 8.0×10-5 mol/L with a detection limit down to 6.7 ×10-7 mol/L.This presented sensor also showed a good stability and an excellent selectivity，and was successfully applied in the simultaneous determination of o-，m- and p-nitrophenol in artificial water samples.关键词：chitosan;carbon nanotubes;ultra-thin carbon paste electrode;nitrophenol isomers;simultaneous determination
- 2081
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- 1172
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- 3
发布时间： - 摘要：It was found that less energy transfer could occur between the acridine orange and alizarin red（AR） in pH 6.0 solution.An appropriate amount of melamine added could react with AR to form a charge transfer complex，in which melamine is an electron donor because of its rich electronic structure and alizarin red is an electron acceptor.Since the maximum absorption wavelength of the complex and the maximum emission wavelength of acridine orange are about the same，the effective energy transfer could occur between acridine orange and the complex so that the fluorescence quenching of the system is more.Fluorescence quenching degree of the system had a good linear relationship with amount of added melamine.Accordingly，a novel fluorescence quenching method for the determination of melamine was established.Under the optimum conditions，the linear range of melamine was in the range of 3.38×10-7-2.40×10-4 mol?L-1 and the detection limit was 1.02×10-7 mol?L-1.RSD was 1.1%.The method was used to determine melamine in commercial milk and milk powder with recoveries of 97.7%-102%.The method is low cost，simple，fast and accurate.Furthermore，the method mechanism was further explored by UV spectroscopy.关键词：fluorescence quenching;melamine;acridine orange;alizarin red;energy transfer
- 2171
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- 1068
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发布时间： - 摘要：A method based on ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）with gel permeation chromatography was developed for the quantitative analysis of 16 kinds of oil-soluble synthetic dyes in feeds.The conditions of sample preparation and analysis were optimized in this thesis.The dyes were firstly extracted with 20 mL of ethyl acetate-cyclohexane（1∶1），and 5 mL of the extract was injected into the gel permeation chromatography（GPC）cleanup system.The elution was performed with a mixture of ethyl acetate-cyclohexane（1∶1） at a flow rate of 5 mL/min.The elution fraction in 15.8-48.3 min was collected.A UPLC separation was carried on a BEH Ｃ18 column（1.0 mm×100 mm，1.7 μm）by gradient elution using methanol -0.1% formic acid as mobile phase at a flow rate of 0.3 mL/min16 kinds of dyes were detected under positive electrospray ionization（ESI）.The method was quantified by the external standard method and the linear ranges for 16 kinds of dyes were in the range of 2-100 μg/L with correlation coefficients greater than 0.99.The average recoveries for 16 kinds of dyes in feeds ranged from 66.4% to 108.5% at three different levels.The limits of detection were 25 μg/kg and the limits of quantitation were 50 μg/kg.The results indicated that the method developed was highly sensitive and selective in determination of 16 kinds of oil-soluble synthetic dyes in feeds.关键词：ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）;oil-soluble synthetic dyes;feeds;gel permeation chromatography（GPC）
- 1795
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- 1044
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发布时间： - 摘要：A fingerprint method was established for the analysis of Hunan Anhua dark tea by high performance liquid chromatography(HPLC).Samples were extracted with water at 90 ℃ thermostat water bath for 20 min.The analysis was performed on a C18 column(5 μm,4.6 mm×250 mm)using methanol-water(containing 0.1% phosphoric acid) as mobile phase by gradient elution at a flow rate of 1.0 mL/min.The detection wavelength was set at 270 nm.The compounds in the dark tea were well separated,and 18 common peaks in chromatograms were selected as characteristic peaks,in which 12 peaks were identified by the standards.Four pattern recognition methods,similarity evaluation,principal component analysis,OPLS-DA and random forest were used to analyze HPLC chromatograms of 78 batches of dark tea samples which originated from Hunan province and other provinces.The differences between Anhua dark tea and other dark teas were visually represented,and some important components were also discovered.The results showed that different origins of dark tea had an obvious difference.The proposed method is simple and of good precision,stability and repeatability.This investigation could provide the fundamental data for identification and quality-assessment of Hunan Anhua dark tea.关键词：dark tea;high performance liquid chromatography(HPLC);fingerprint;random forests;producing area;discriminate analysis
- 1947
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- 1023
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- 2
发布时间： - 摘要：The enantiomeric resolution of four β2-agonists,namely mabuterol,bambuterol,clenbuterol and clenproperol,was studied on Pikle type α-Burke-2 chiral stationary phase.Factors affecting the enantioresolution,such as type and concentration of the salts additives, content of organic solvents and column temperature were investigated.The optimal separation conditions were as follows:mobile phase:dichloromethane-ethanol（19∶1）containing 5 mmol/L ammonium acetate,flow rate:2.0 mL/min,column temperature:20 ℃.Under the above conditions,the enantiomers of clenbuterol and clenproperol were successfully separated with resolutions of 1.78 and 1.68,respectively.The enantiomers of bambuterol and mabuterol were partly separated with resolutions of 1.00 and 1.25,respectively.The thermodynamic parameters of four β2-agonists on α-Burke-2 chiral stationary phase were calculated,the enantioselectivity was proved to be enthalpocally controlled.The chiral recognition mechanism was discussed,π-π interaction and hydrogen binding between α-Burke-2 chiral stationary phase and β2-agonists were confirmed to be the interactions responsible for the chiral discrimination.关键词：Pirkle-type chiral stationary phase;β2-agonists;enantiomers;chiral separation;high performance liquid chromatography
- 1981
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- 937
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- 1
发布时间： - 摘要：The combustibility of the cut tobacco under different relative humidity（RH） was investigated by simultaneous thermal analysis.The results showed that:①The moisture content of cut tobacco increased with the increase of RH，and there was a linear correlation between the moisture content and RH.②By comparing the weight loss rate of every stage，different moisture contents of the cut tobacco had effect on their combustion reaction and pyrolysis reaction.Between 50% and 60% of the RH，there was a turning point where the major trend of weight loss rate varied.③The combustion characteristics of cut tobacco were decreased with the increase of RH，RH was significantly correlated with the moisture content of cut tobacco and the average rate of combustion.The moisture content of cut tobacco was negatively significantly correlated with the ignition temperature.However，RH had no significant correlation with the combustion characteristics.关键词：cut tobacco;moisture content;simultaneous thermal analysis;combustion characteristic;correlation
- 1770
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- 943
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- 2
发布时间： - 摘要：A new modified electrode（CS-AB/GCE）prepared with acetylene black and chitosan was used to determine naphthol isomers.The properties of electrode surface were characterized by SEM and Nyquist plots.The electrochemical behaviors of α-N and β-N on CS-AB/GCE was studied by cyclic voltammetry（CV）.Influences of type of buffer solution， ratio of CS to AB，amounts of CS and AB，pH value，concentration of naphthol isomers and scan rate were discussed.The results indicated that there were two oxidation peaks respectively belonged to α-N and β-N in pH 7.0 PBS buffer.The oxidation peak currents of both α-N and β-N were linear with scan rate（v） in the range of 20-200 mV/s，which showed that the electrode processes of α-N and β-N were controlled by adsorption.Some important parameters for these electrochemical processes were also determined.The effect area（A），electron number（n） and proton number（m） of the modified electrode were obtained to be 0.390 2 cm2，1 and 1，respectively.The adsorption capacity were 2.788×10-9 mol/cm2 for α-N， and 5.603×10-9 mol/cm2 for β-N.Under the optimal conditions，the differential pulse voltammetry（DPV） with derviative technique was used to determine naphthol isomers quantitatively.Good linear relationships between peak currents and concentrations of α-N and β-N were observed in the range of 2.5×10-6-1.0×10-4 mol/L，and the detection limits（S/N=3） were 3.4×10-7 mol/L for α-N and 2.4×10-7 mol/L for β-N.The proposed method was applied in the determination of α-N and β-N in water samples with spiked recoveries of 96.7%-105.1% and 98.8%-103.9%，respectively.关键词：naphthol isomers;acetylene black;chitosan;EIS;differential pulse voltammetry;derivative technique
- 2234
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- 1012
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- 2
发布时间： - 摘要：This study aims at getting the relationship between semi-volatile organic pollutants’ recoveries of liquid-liquid extraction in water and their n-octanol/water partition coefficients（lgKow）.The results showed that,the semi-volatile organic pollutants’ recoveries in water and their n-octanol/water partition coefficients（lgKow） has the following contact:when lgKow＜5,the semi-volatile organic pollutants’ recoveries in water range from 16.1% to 56.1%;and when lgKow ＞5,the semi-volatile organic pollutants’ recoveries in water range from 59.5% to 124.9%.In the same way,a study on the relationship between semi-volatile organic pollutants’ recoveries in water and their solubility（lgS） was also carried out,the study about lgS could be used to verify the conclusion obtained.And much the same conclusion was drawn,when lgS＞-0.60,the semi-volatile organic pollutants’ recoveries ranged from 16.1% to 56.1%;and when lgS＜-0.60,the semi-volatile organic pollutants’ recoveries ranged from 59.5% to 124.9%.From above,the conclusion derived from semi-volatile organic pollutants’ recoveries and lgKow and lgS,respectively,is consistent.During the course of detecting environmental groudwater samples,the recoveries of laboratory fortified blanks and their n-octanol/water partition coefficients（lgKow） were used to verify the conclusion,and the results showed that it is consistent with that derived by discussing the relationship between semi-volatile organic pollutants’ recoveries and n-octanol/water partition coefficients:when lgKow＞5,or lgS＜-0.60,the recoveries ranged from 85.3% to 115.9%.关键词：semi-volatile organic compounds;recovery;n-octanol/water partition coefficient;solubility
- 1750
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- 966
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- 1
发布时间： - 摘要：Two new ways of cellulose nanocrystal（CNC）film fabrication and characterization of the films by infrared reflection absorption spectroscopy（IRRAS）and atomic force microscopy（AFM）were discussed in this paper.CNC films can be formed via electrostatic driven physisorption to an amine-terminated self-assembled monolayer（SAM）on evaporated gold substrate either by immersion in CNC suspensions or through a spin-coating process.AFM can not only characterize the surface topography of non-conductive CNC films and analyze the roughness of the surface，but also reach accurate film thickness through scratching technique.AFM height images showed that CNC films are well packed with rod-like CNC nanoparticles.Through at least three times of experiments and accurate statistical analysis，it is known that spin-coated CNC films，with a roughness RMS of approximately 2.7 nm，are slightly smoother than immersed CNC films.According to the AFM scratching results，the thickness of the immersed CNC film is maximum 15 nm due to the repulsion between particles，while spin coating process can make much thicker CNC films，with a thickness of over 50 nm.The relationship between CNC suspension concentrations and spin-coated CNC film thickness was investigated.It was found that the thickness can be well controlled by the CNC solution concentration.The IRRAS results also confirmed that the spin-coated CNC film thickness increases with the increase of CNC suspension concentrations.The successful fabrication of CNC films provided a high-surface area substrate using green materials for studying surface chemistry，and could be used in pharmaceuticals，drug delivery，biosensors，solar energy battery，and other fields.关键词：cellulose nanocrystal（CNC）;film thickness;infrared reflection absorption spectroscopy（IRRAS）;atomic force microscopy（AFM）;AFM scratching technique
- 1785
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- 1159
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- 0
发布时间： - 摘要：A novel method of microchip capillary electrophoresis with electrochemiluminescence (ECL) detection for the rapid determination of procaine hydrochloride was developed.Tris (2,2’-bipyridyl)-ruthenium (Ⅱ)(Ru(bpy)2+3) was chosen as ECL reagent,a 300 μm diameter platinum disc working electrode was embedded in a titanium tube which provides an adequate holding for the working electrode and acts as counter electrode，and an Ag/AgCl wire reference electrode was inserted in the ECL detection cell to form a three-electrode system.The factors influencing the performances of separation and detection,such as pH values of running buffer and detection buffer,detection potential and separation voltage,were investigated.Under the following optimized conditions:running buffer:10 mmol/L phosphate buffer (pH 4.0),separation voltage:300 V/cm,detection solution:5 mmol/L Ru(bpy)2+3 in 50 mmol/L phosphate buffer(pH 7.0),detection potential:1.25 V,procaine hydrochloride was separated and detected in 40 s.The linear response of procaine hydrochloride ranged from 10 μg/mL to 2 000 μg/mL(r2=0.999 1).The limits of detection(S/N=3) was 3.0 μg/mL.The spiked recoveries were in the range of 97%-99% with relative standard deviations of 1.8%-2.2%.This method was simple,rapid and reliable,and could be used for the determination of procaine hydrochloride content in injection.关键词：microchip capillary electrophoresis(MCE);electrochemiluminescence(ECL) detection;procaine hydrochloride;tris (2,2′-bipyridyl)-ruthenium (Ⅱ)(Ru(bpy)2+3)
- 1809
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- 995
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- 2
发布时间： - 摘要：Urinary oxalate was successfully determined by ion chromatography with suppressed conductivity detector in the presence of ascorbic acid.The sample was diluted with deionized water,and filtrated through a 0.22 μm filter.Then the sample was directly separated with IonPac AS12A anion exchange column（200 mm×4 mm） employing 15 mmol?L-1 NaHCO3（pH 8.3） as eluent,and detected with conductivity detector.The result showed that oxalate could be well separated from other anions in urine within 16 min.Under the same condition,urinary ascorbic acid does not decompose into oxalate within 80 min,thus having no influence on the determination of oxalate.The calibration curve was linear in the range of 0.2-40 mg?L-1 with a correlation coefficient（r） of 0.999 9.The detection limit was 0.02 mg?L-1.The average recoveries were in the range of 96.9%-103.3%.The method was rapid,selective and sensitive,and was applied in the determination of urine samples with satisfactory results.关键词：ion chromatography;oxalate;ascorbic acid;urine
- 1854
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- 846
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发布时间： - 摘要：Mercury（Hg2+） ions deposited on the surface of gold nanoparticles（AuNPs） absorbing single strand DNA（ssDNA） can promote the peroxidase-like activity of AuNPs.Based on this，a highly sensitive detection of Hg2+ was developed.Here it was found that ssDNA can promote the activity of AuNPs-Hg2+ mimetic peroxidase due to the adsorption of ssDNA on the AuNPs surface.The catalytic activity of AuNPs-Hg2+ mimetic peroxidase increases with increase of ssDNA concentration.The ssDNA-AuNPs-Hg2+ mimetic peroxidase can be applied in the detection of Hg2+ in a linear range of 10-1 000 nmol/L with a detection limit as low as 3.0 nmol/L under optimized condition.The method was simple，rapid，low cost and stable，and had high application potential to detect Hg2+ in the environment，food and other samples.关键词：Hg2+;detection;gold nanoparticle;mimetic peroxidase
- 1886
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- 950
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- 3
发布时间： -
Preparation of Mesoporous Carbon/Gold Nanoparticles Composite Modified Electrode and Its Application
摘要：In this paper,the conditions for preparation of the mesoporous carbon/gold nanoparticles modified glassy carbon electrode were investigated.It was found that the modified electrode had effective catalytic activity to hydroquinone(HQ).Compared to those of HQ on the mesoporous carbon modified glassy carbon electrode in electrochemical response,the oxidation peak current and reductive peak current of HQ were greatly increased on the chemically modified electrode,and the oxidation peak potential of HQ decreased.The modified electrode showed a good catalytic effect to HQ.In the optimum conditions,the electrochemical behavior of HQ on the modified electrode was studied.The results showed that concentration of HQ in the ranges of 3.0×10-8-1.0×10-6 mol/L and 1.0×10-6-1.0×10-4 mol/L had good linear relationships between electrochemical response signals and HQ concentrations,with a detection limit(S/N=3) of 1.0×10-8 mol/L.This method was applied in the determination of HQ in real sample with high accuracy and reproducibility.关键词：mesoporous carbon;gold nanoparticles;hydroquinone;modified electrode- 2221
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- 994
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发布时间： - 摘要：A rapid method was developed for the detection of 5 common fatty acids,including palmitic acid，stearic acid，oleic acid，linoleic acid and linolenic acid,in vegetable oils based on ultra-performance convergence chromatography-mass spectrometry(UPC2-MS).The sample was dissolved with n hexane，followed by clean up of extract using 022 μm organic phase filter.The fatty acids were separated in 3 min on a column of ACQUITY UPC2 BEH 2-EP(2.1 mm i.d.×100 mm,1.7 μm) by gradient elution with carbon dioxide and methanol-acetonitrile（by volume，1∶1） system，and finally detected by MS detector.The results showed that the calibration curves of five analytes were linear in the range of 0.5-100 mg/L with correlation coefficients（r2） not less than 0.998 5.The recoveries for five fatty acids at three spiked levels were in the range of 90.5%-105.4% with relative standard deviations of 0.8%-2.9%.The limits of detection for the target compounds in the method ranged from 0.07 mg/L to 0.26 mg/L.In comparison with other methods，this method was simple,rapid,and had good separation effect.Furthermore，the method could provide reference for further research and application of UPC2 technology in oil related analysis field without derivatization of fatty acid samples.关键词：ultra-performance convergence chromatography-mass spectrometry(UPC2-MS);vegetable oils;underivatization;fatty acids
- 1891
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- 999
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- 5
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