摘要:A liquid chromatography-quadrupole/time-of-flight mass spectrometric(LC-TOF/MS) method was developed for the determination of 36 forbidden substances,belonging to β-agonists and anabolic hormones in feeds based on liquid chromatography-quadrupole/time-of-flight mass-spectrometry (LC-TOF/MS).Acetonitrile and mixed sorbents were added to the homogeneous feeds sample,and then followed by the processing steps,involved vortexing dispersion,shaking extraction,centrifugation and concentration(namely the modified QuEChERS method).The total analytes were rapidly extracted and purified.The extract was separated on a C18 column(150 mm×2.1 mm,2.7 μm) using methanol-0.1% formic acid as mobile phase by gradient elution,and analyzed under ESI positive ionization mode.Full scan experiments(TOF/MS & Product ion) were performed over the m/z range of 100-1 000 Da.The quantitative analysis was carried out by extracting peak area with accurate mass.The confirmatory analysis of target compounds was performed with the qualitative fragments and retention time.Under the optimal conditions,a good separation and high sensitivity analysis of 36 substances were obtained with absolute value mass error below 7.3.The calibration curves were linear in the range of 10.0-200.0 μg/kg with correlation coefficients more than 0.99.The average recoveries at three spiked levels were in the range of 65%-120% with relative standard deviations (RSDs) no more than 24%.The proposed method was convenient,reliable and simple,and was suitable for the high-throughput and rapid screening analysis of forbidden drugs in feeds.
关键词:forbidden substances;liquid chromatography;time-of-flight mass spectrometry (TOF/MS);feeds;QuEChERS
摘要:Because of their unusual electronic structures and properties,potential applications of fullerene pyrrolidine derivatives have attracted much interest in many fields,especially in materials science.In this study,eight fulleropyrrolidine derivatives were characterized by ion trap mass spectrometry(ESI IT-MS)under electrospray ionization condition.The obtained results showed that fullerene-N-methylpyrrolidine derivatives are readily ionized with the loss of one electron by negative-ion ESI IT-MS.Some fullerene-N-methyl pyrrolidine derivatives can be protonated with positive-ion ESI IT-MS or deprotonated with negative-ion ESI IT-MS when there are some groups or atoms in the molecular structure easy to catch or lose active hydrogen.The pyrrole ring of fulleropyrrolidine derivatives is easy to lose during the process of negative-ion ESI IT-MS/MS,and C60 can be observed in all the ESI IT-MS/MS spectra of fullerene pyrrolidine derivatives.Retro-cycloaddition reactions take place in the structure of the pyrrole ring to produce mono-substituted methanofullerene with the loss of CH2‖N—CH3.Useful informations about molecular weight and structure can be obtained by ESI-MS and ESI MS/MS.
摘要:A simple method based on three-phase hollow fiber liquid-phase microextraction (HF-LPME) combined with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of benzoic and sorbic acids in drinks.The optimum extraction conditions for the three-phase hollow fiber liquid phase microextraction were as the follows:the porous membrance of hollow fiber was full of 1-octanol,the pH values of the donor phase and the acceptor phase were 2.7 and 13.6,respectively.HF-LPME was accomplished at room temperature,the extraction time was 30 min and the stirring speed was 1 000 revolutions per minute (rpm).The UPLC-MS/MS method was performed with Waters ACQUITY UPLCTM BEH C18(50 mm×2.1 mm,1.7 μm)using methanol-10 mmol/L ammonium formate as mobile phase by a gradient elution,at a flow rate of 0.25 mL/min.The target compounds were detected under ESI in negative mode,then analyzed in multiple reaction monitoring(MRM) mode,and the external standard method was used for quantification.The results showed that there are good linearities in the range of 0.05-5.0 mg/L with correlation coefficients higher than 0.997.The limits of detection(LOD) of benzoic and sorbic acids were 0.005,0.01 mg/L and the limits of quantitation(LOQ) were 0.01,0.02 mg/L,respectivley.The recoveries (n=6)at spiked levels of 0.1,1.0,4.0 mg/L were in the range of 91%-103% with RSDs less than 6.0%.This method was successfully applied in the analysis of benzoic and sorbic acids in different kinds of drinks.
摘要:A fingerprint analysis method was developed for the quality control of Deng-s herbal tea granule(DHTG) by ultra high performance liquid chromatography coupled with mass spectrometry (UHPLC-MS).The samples were extracted by Soxhlet extraction with methanol as solvent for 60 min.UHPLC-MS separation was performed on a Waters ACQUITY HSS T3 C18(150 mm×3.0 mm,1.8 μm) column by gradient elution with 0.5% formic acid-acetonitrile as mobile phase,at the temperature of 35 ℃ and a flow rate of 0.8 mL/min.The base peak chromatograms(BPC) obtained with negative-ion electrospray ionization(ESI) mass spectra were selected for the fingerprint analysis.A good separation of 32 common peaks was achieved in 15 min,and 15 of them were confirmed by reference substances.Similarity evaluation was performed by a professional software named Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine(Version 2004A),and the similarity among 15 batches of samples was no less than 0.960,which confirmed that the quality of DHTG was stable.The principal component analysis(PCA) was performed by using the samples as variables and the relative peak areas of 32 common peaks as observations.A fine difference among DHTG samples was expressed in the PCA result.The developed method was fast and efficient,and was suitable for the quality control of DHTG.
关键词:ultra high performance liquid chromatography-mass spectrometry;fingerprint;simi-larity evaluation;principal component analysis;Deng-s herbal tea granule;quality control
摘要:A novel method using ionic liquid independent disperse liquid-liquid microextraction(IL-IDLLME) coupled with first derivative spectra was developed and applied in the determination of tartrazine(E102) and brilliant blue FCF(E133) in soft drink,candy and jelly samples.1.Octyl-3-methylimidazolium tetrafluoroborate ([C8MIM][BF4]) showed a high preconcentration for the two food dyes,and their first-derivative spectra will not interfere with each other.Under the optimal conditions,the calibration curves were linear in the ranges of 20-1 000 μg ? L-1 for E102 and 3-150 μg ? L-1 for E103.The detection limits based on three times the standard deviation of the blank(3Sb) were 6.60 μg?L-1for E102 and 0.84 μg?L-1for E103.The proposed method was applied successfully in the determination of two food dyes in food samples without any interference.
关键词:tartrazine;brilliant blue FCF;food;ionic liquid;disperse liquid-liquid microextraction
摘要:An highly sensitive,stable and label free electrochemical immunosensor for the detection of 1-pyrenebutyric acid(PBA) was developed based on graphene(GS) and chitosan(CS) composites modified glassy carbon electrode (GS-CS/GCE).The proposed GS-CS/GCE was activated by the 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride(EDC) and N-hydroxysuccinimide (NHS) (4∶1) solution in order to covalently immobilize PAHs antibody (anti-PAHs).The morphology of the GS-CS composites film was characterized by transmission electron microscopy(TEM).In phosphate buffer solution(pH 7.0) containing 0.1 mol/L KCl and 10 mmol/L K3Fe(CN)6 solution (0.1 mol/L KCl+10 mmol/L K3Fe(CN)6+0.1 mol/L PBS(pH 7.0)),the electrochemical behaviors of the modified electrode and the electrochemical properties of the immunosensor were studied by cyclic voltammetry (CV) and differential pulse voltammetry(DPV).Due to the synergistic effect of grapheme and chitosan,the peak current of GS-CS/GCE in the supporting electrolyte was largely increased,which was attributed to improve sensitivity of the immunosensor.Under the optimized conditions,the immobilization amount of antibody was significantly improved on the modified electrode,resulting in amplifying the molecular recognition ability of the modified electrodes.Because of the poor conductivity of the antybody-antigen immunocomplex,the current response of the proposed immunosensor decreased linearly with increase of PBA concentration.The linear range of theimmunosensor for PBA detection was 0.1-80 μg/L with a detection limit of 0.03 μg/L.With excellent selectivity and reproducibility,the proposed immunosensor was applied in the determination of PBA in the real sample with spiked recoveries of 90%-105%.
摘要:A new compound,3,8-dimethyl-4′-methoxyflavone(DMMOF) was synthesized and characterized by 1H NMR,13C NMR,IR spectra.The atomic force microscope(AFM),fluorescence spectroscopy and ultraviolet absorption spectroscopy were explored to study the interaction between DMMOF and BSA in physiological buffer solution(pH 7.4).The experiment results showed that the diameter of BSA-DMMOF was 17.705 nm while it was 2.747 nm for BSA and 2.284 nm for DMMOF.The fluorescence quenching mechanism between DMMOF and BSA was deduced to be static quenching procedure according to ultraviolet absorption spectra and Stern-Volmer equation.The binding constants and their binding sites number at different temperatures were calculated according to double logarithm regression curve.The thermodynamic parameters ΔH,ΔS and ΔG were obtained to be-116.86 kJ?mol-1,-279.55 J?mol-1?K-1and -32.14 kJ?mol-1,respectively,based on the thermodynamic equations,which indicated that the action force was mainly van der Waals force and hydrogen bonds.The binding distances(r) between donor(BSA) and acceptor (DMMOF ) was estimated to be 1.22 nm(306 K) based on the F-rster non-radioactive energy transfer theory.In addition,the effect of DMMOF on the conformation of BSA was analyzed by synchronous fluorescence spectroscopy,which indicated the addition of DMMOF will not change the conformation of BSA.Associated with ultraviolet absorption spectroscopy,the ring A of DMMOF was inferred to combine with the tryptophan-134 residues and the tyrosine residues of BSA.
摘要:By using surface molecular imprinting technique,a molecularly imprinted polymer(MIPs) for nonylphenol(NP) was synthesized on the surface of silica microparticles(SiMPs) with NP as template molecule,2-methacrylic acid(MAA) as functional monomer and vinyltrimethoxysilane(VTTS) as grafting agent.The homogeneous dispersion of microspheres and larger specific surface area of the SMIP were observed by means of scanning electron microscopy(SEM) and BET adsorption apparatus.The characteritic of chemical structures in the modification procedure of MIP was studied by fourier transform infrared spectroscopy(FTIR),and the adsorption property between the template molecule and functional polymer was evaluated by equilibrium adsorption method.The results indicated that the maximum adsorbing capacity of SMIP to NP was 184.6 mg/g.In addition,the adsorption capacity of SMIP to NP was higher than those of its structural analogues,e.g.p-octylphenol and bisphenol A,indicating that SMIP has a good recogntion capacity to NP.
摘要:A gas chromatography–tandem ion trap mass spectrometric(GC-MS/MS) method was developed for the simultaneous determination of four barbiturates residues(e.g.barbital,amobarbital,secobarbital sodium and phenobarbital) in pig liver and kindey.The barbiturates residues were extracted by ultrasonic assistant extraction with acetonitrile.The extracts were concentrated and redissolved by 5 mL 0.1 mol/L K2HPO4 (pH 7.4),cleaned up by C18 SPE cartridge using hexane–ethyl acetate(7∶3) mixture as eluting solvent,then derivatized with CH3 I by microwave irradiation.The methylated barbiturates were separated on a TR-5MS capillary column and detected with an ion trap mass detector.Electron impact(EI) ion source operated in MS/MS mode was adopted for identification and external standard method was employed for quantification.Good linearities (r>0.99) were obtained in the range of 5-100 μg/L.The limits of detection(LOD,S/N≥3)for four barbiturates were no more than 0.65 μg/kg in liver and 1.00 μg/kg in kidney.The limits of quantitation(LOQ,S/N≥10) were no more than 2.20 μg/kg in liver and 3.35 μg/kg in kidney.The recoveries of four barbiturates at spiked levels of 5,10,15 μg/kg ranged from 68% to 90% with relative standard deviations(RSDs) no more than 10%.The results indicated that the method was accurate for the determination of barbiturate drug residues in animal tissues.
关键词:barbiturates;gas chromatography–tandem ion trap mass spectrometry;microwave assisted derivatization;liver;kidney;ultrasonic extraction;C18 SPE cartridge
摘要:A method was developed for the determinations of seven BTEX(the term used for a group of volatile aromatic compounds),including benzene,toluene,ethylbenzene,p-xylene,m-xylene,o-xylene and styrene,in seawater by purge and trap gas chromatography-mass spectrometry under selective ion monitoring (SIM) mode.The result showed that the calibration curves of seven BTEX were in the range of 100.0-2 000.0 ng/L,with correlation coefficients of 0.999 6-0.999 8.The method detection limits ranged from 5.9 ng/L to 10.7 ng/L.The average recoveries for seven BTEX at two spiked concentration levels of 250.0 ng/L and 1 000.0 ng/L were in the range of 84%-105% and 96%-97%,with relative standard deviations(RSDs,n=6) of 3.7%-6.5% and 2.1%-3.3%,respectively.This method is accurate and rapid,and has high enrichment efficiency without any organic contamination,which can be used to analyze seawater samples containing trace BTEX.
关键词:BTEX;purge and trap;gas chromatography-mass spectrometry
摘要:The enantiomeric resolution of quizalofop-ethyl on Chiralpak IC column(cellulose-tris(3,5-dichlorophenylcarbamate) immonilized on silica) was studied.Effects of mobile phase composition,flow rate and temperature on the chiral separation of enantiomers were investigated.The result showed that a good baseline separation of quizalofop-ethyl enantiomers was obtained by using n-hexane-isopropanol(95∶5) as mobile phase with a flow rate of 1.0 mL/min at 25 ℃.The resolution was up to 3.97,in which R-enantiomer was firstly eluted.The limits of detection(LOD) for both of enantiomers were 0.045 mg/L and the limits of quantitation(LOQ) were 0.15 mg/L.The Van′t Hoff plot of the lnα versus 1/T showed a good linearity with correlation coefficients higher than 0.99 at column temperature of 15-35 ℃.The resolution factor was decreased with the increase of column temperature.The enthalpy and entropy change difference showed that the enantioseparation of quizalofop-ethyl enantiomers was enthalpy driven.
关键词:Quizalofop-ethyl;enantioseparation;Chiralpak IC column;HPLC
摘要:A simultaneous determination method was developed for the quantification and confirmation of 8-aromatic-compounds,including benzene,toluene,ethylbenzene,p,m-xylene,o-xylene,phenol,naphthalene and anthracene,in polyurethane waterproof coating by gas chromatography-mass spectrometry(GC-MS).The extraction and separation efficiencies of targeted compounds were investigated by using organic solutions of ethyl acetate,butyl acetate,acetone,acetonitrile and ethanol.The 8 aromatic compounds were extracted with ethyl acetate,and determined by GC-MS under the selected ion mode(SIM) using undecane as the internal standard.The calibration curves showed good linearities in the range of 0.01-2.40 g/L with correlative coefficients(r) larger than 0.99.The average recoveries were in the range of 95%-109% with relative standard deviations(RSD,n=6) of 0.7%-4.9%.The limits of detection(LOD,S/N≥3) were all 0.001 g/kg.This method was applied in the determination of aromatic compounds in 10 polyurethane waterproof coatings on sale with satisfactory results. The method shows the advantages of good reproducibility,high sensitivity and simple operation.
摘要:A new method was proposed for the determination of trace cadmium,chromium and lead by graphite furnace atomic absorption spectrometry(GFAAS) after preconcentration with dithizone-modified nanometer titanium dioxide(TiO2-DZ).The conditions of adsorbing and desorbing of nanometer TiO2-DZ for Cd2+,Cr3+and Pb2+ was optimized.The results indicated that the three metals could be quantitatively preconcentrated on the nanometer material at pH 5.0 and the static adsorption capacity of Cd,Cr and Pb were 13.3,5.5 and 21.8 mg/g,respectively.The preconcentrated metal ions could be completely eluted with 5 mL 0.1 mol/L HNO3.Under the optimum conditions,the detection limits (3σ,n=11) for Cd2+,Cr3+and Pb2+ were 0.18,0.51 and 1.92 ng/L,respectively,and the relative standard deviations were 2.8%,2.3% and 1.0%,respectively.The spiked recoveries ranged from 96% to 101%.The proposed method was successfully applied in the determination of trace cadmium,chromium and lead in natural water samples with satisfactory results.
关键词:nanometer TiO2;dithizone;separation and preconcentration;metal ions;graphite furnace atomic absorption spectrometry
摘要:An effective GC-MS/MS method was established for the simultaneous determination of contents of 20 phthalate plasticizers in leather products.The phthalate plasticizers in leather products were ultrasonically extracted at room temperature using hexane as the extraction solvent,then the extract was purified with neutral alumina solid extraction column,followed by analysis of gas chromatography-tandem mass spectrometry.The method was simple,rapid,sensitive and accurate.The limits of quantitation(LOQ,S/N=10) of DIDP,DINP and DMPP were 0.2,0.2 and 0.1 mg/kg,respectively,while the LOQs for the other 17 phthalate plasticizers were all less than 50 μg/kg.The relative standard deviations(RSDs) of the method were all less than 12% ,and the spiked average recoveries ranged from 86% to 95%.The proposed method was applied in the determination of phthalate plasticizers in 47 commercially available leather products,and two of which were detected containing phthalate plasticizers.
关键词:ultrasonic extraction;gas chromatography tandem mass spectrometry;phthalate plasticizer;leather product
摘要:Based on the UV-Vis absorption characteristics of preservatives and partial least squares variable selection method,the concentration forecasting model of benzoic sodium and sorbic potassium mixture solution was studied.The ultraviolet absorbance spectra of these complexes were examined,and the results indicated that the response signals and concentrations presented good linearities in the ranges of 0.1-16.0 mg/L for benzoic sodium and 0.1-6.0 mg/L for sorbic potassium.The detection limits were 0.05 mg/L for benzoic sodium and 0.01 mg/L for sorbic potassium.The reported model was applied in the simultaneous determination in food samples such as drinks,wine,cake and preserves without any preliminary chemical separation.The relative standard deviations were less than 10% and the recoveries were in the range of 82%-107%.The detection data are consistent with those of the national standard method.
关键词:sodium benzoate;potassium sorbate;UV-Vis absorption;orthogonal experiment;partial least squares variable selection method
摘要:A chitosan graphene oxide self assembled films modified glass carbon electrode was prepared and characterized by the electrochemical impedance spectroscopy(EIS).The behaviors of SudanⅠon the modified electrode were investigated by cyclic voltammetric method.The results indicated that an oxidation peak was observed on the modified electrode and no reduction peak was found,which showed that the electrochemical reaction of SudanⅠon the electrode was an irreversible process.The oxidation peak currents were linear to scan rates in the range of 50-250 mV?s-1,indicating that the electrode process was controlled by absorption.The numbers of electron and proton transferred in the electrode reaction were both 1.The modified electrode showed a good linear current response to SudanⅠin the range of 6.0×10-8-5.0×10-6 mol/L by differential pulse voltammetry with a correlation coefficient of 0.995 and a detection limit of 4.45×10-8 mol/L.With the advantages of simple preparation,high sensitivity,low cost,excellent reproducibility and stability,the proposed method could be used in the determination of Sudan Ⅰin salted duck egg yolk samples.
摘要:A new method was developed for the determination of carbofuran,carbaryl and atrazine in environmental water by ultrahigh-pressure liquid chromatography(UPLC) combined with solid phase extraction(SPE).Through the investigation of the effects of mobile phase,UV detection condition,SPE cartridges,SPE load flow rate and filter materials,the optimum conditions were obtained.Water sample was loaded on the Bond Elute Plexa SPE cartridges with a flow rate of 5-10 mL/min.The analytes were eluted with methylene chloride in SPE cartridges.The eluted solvent was concentrated and redissolved in methanol/water(1∶1).The analysis conditions were as the follows:UV wavelength of detection:222 nm,chromatographic column:ACQUITY UPLC BEH C18(2.1 mm×50 mm,1.7 μm),mobile phase:methanol-water(55∶45), flow rate:0.4 mL/min.Under the optimal conditions,three analytes were separated by baseline within 1.5 min.The correlation coefficients of carbofuran,carbaryl and atrazine standard curves were more than 0.999 in the range of 0.1-2.0 mg/L.The relative standard deviations of nine parallel injections of carbofuran,carbaryl and atrazine were 1.7%,0.2% and 0.7%,respectively,and their method detection limits(S/N=3) were 0.04,0.003,0.004 μg/L,respectively.The recoveries of three compounds at high and low spiked levels were in the range of 74%-94%. This method has the advantages of saving time,simple operation and sensitivity,and could be applied in the detection of trace carbofuran,carbaryl and atrazine in environmental water.
摘要:Different generatons of polyamidoamine dendrimers(PAMAM) with tri(2-aminoethyl)amine at the core were synthesized using divergent synthesis.The products were characterized by FTIR and 1H NMR.The results showed that the products synthesized had a precise molecular structure and the molecular structure was also correspond to the theoretical structure of the PAMAM dendrimers.The PAMAM possess a large number of primary amine groups,tertiary amine groups and amide groups,which can complex with Zn2+.In this paper,the complexation between PAMAM dendrimers and Zn2+ were studied by fluorescence spectrophotometry,and effects of the generation of PAMAM,molar ratio of Zn2+ to PAMAM,pH value of the solution,reaction temperature and reaction time on the complexation were discussed.The results showed that the number of complexed Zn2+ increased with the increase of generation of PAMAM and the experimental results were almost simlar to the theory value.As the molar ratio of Zn2+ to PAMAM increased,the complex forms cuold chang.The pH value of the solution also had a great effect on the complexation of PAMAM-Zn2+.The primary amine groups and tertiary amine groups of PAMAM were protonated under strong acidic conditions and Zn2+ was replaced by H+,resulting in the release of Zn2+.This phenomenon indicated that PAMAM dendrimers could be recycled.It was also found that the reaction temperature and reaction time could influence the complexation of Zn2+-PAMAM dendrimers.The reaction extent of complex system was enhanced with the increase of reaction temperature and reaction time.
摘要:A molecularly imprinted polymer(MIP) for nimodipine was prepared by bulk polymerization method,utilizing methacrylic acid(MAA) as functional monomer,trimethylol propane triacrylate(TMPTA) as cross-linking agent.The selective recognition characteristics of MIP for nimodipine,nitrendipine and felodipine drug molecules were studied in equilibrium binding experiment.The static adsorption distribution coefficient(KD) values of the three drugs were 0.221 4,0.197 2 and 0.051 4,respectively.The results showed that MIP had a high affinity and selectivity to nimodipine.Type I adsorption isotherm was obtained by determining the adsorptive capacity at different temperatures,and an exothermic process was confirmed by the change of adsorption capacity with temperature.To further study the adsorption mechanism of the imprinted polymer and its thermodynamic properties,the changes of entropy,enthalpy and Gibbs free energy were estimated in the adsorption process at different temperature.The results showed that the adsorption process of imprinted polymer was controlled by enthalpy.
摘要:A grapgene modified glassy carbon electrode was fabricated by cyclic voltammetry and was characterized by IR,XRD and SEM techniques.The electrochemistry behavior of hydrazine on the modified electrode was also investigated.The results showed that the modified electrode had high electrocatalytic activity to the oxidation of hydrazine.Based on this,an amperometry technique for the determation of hydrazine was established.Under the optimum conditions,the oxidation peak current had linear relationships with concentration of hydrazine in the ranges of 1.0×10-8-4.4×10-7mol?L-1 and 4.4×10-7-1.3×10-4 mol?L-1 with a detection limit(3sb) of 9.9×10-9 mol?L-1.The proposed method was applied in the determination of hydrazine in simulation water with spiked recoveries of 100%.
摘要:A gas chromatography-mass spectrometric method based on deuterium isotope internal standard was developed for the rapid determination of musk xylene(MX) in food flavors.In order to disperse sample matrix into extraction solvent,samples were distributed by use of a vortex mixer,and then extracted for 20 min with an ultrasonic generator.The influences of solvent type,solvent consumption and ultrasonic time on extraction efficiencies of the target compounds were discussed.The analyte was quantitatively analyzed by deuterium isotope internal standard method under selected ion monitoring(SIM) mode.The influences of different polarity chromatographic columns on separation were analyzed,the characteristic ions and their abundances were determined.Under the optimal conditions,the calibration curve of MX was in the range of 0.025-0.5 mg/L with a correlation coefficient of 0.999 6.The average recoveries were in the range of 94%-116% with relative standard deviations of 4.2%-6.5%.The detection limit and quantitation limit of MX were 0.11 mg/kg and 0.38 mg/kg,respectively.The results showed that the method was simple,rapid,sensitive and accurate,and was suitable for the rapid determination of MX in food flavors.
摘要:A method was developed for the determination of ionic liquid anion of p-toluenesulfonate by ion chromatography with direct (non-suppressed) conductivity detection.Chromatographic separation was performed on a Shim-pack IC-A3 anion exchange column.The influences of mobile phase types and column temperature on retention time of p-toluenesulfonate were investigated.The optimal chromatographic conditions for the determination of p-toluenesulfonate were using 1.2 mmol/L citric acid-15% acetonitrile(pH 5.0) as mobile phase with a column temperature of 45 ℃ and a flow rate of 1.0 mL/min.Under the optimal conditions,a good separation of p-toluenesulfonate with common inorganic anions(e.g.fluoride,chloride,bromide and nitrate) was obtained.The calibration curve for p-toluenesulfonate was linear in the range of 4.0-100.0 mg/L with a detection limit(S/N=3) of 1.22 mg/L.The relative standard deviations(n=5) for retention time and peak area of p-toluenesulfonate were 0.42% and 1.8%,respectively.The method was successfully applied in the determination of p-toluenesulfonate in ionic liquids with spiked recoveries of 99.6%.This method is simple,accurate,reliable and practical,and could meet the requirements for quantitative analysis of p-toluenesulfonate in ionic liquids.
摘要:A method for the quantitative determination of carbamazepine in blood by solid phase extraction(SPE) combining with LC-MS/MS was developed.The carbamazepine in the blood sample was extracted with SPE and separated with Waters AtlantisTM dC18column(150 mm×3.9mm,5 μm).The detection of carbamazepine was performed using electrospray ionization source,under positive ion mode and multiple reaction monitorring mode with SKF-525A as the internal standard.The calibration curve was linear in the range of 100-6 000 μg/L for carbamazepine,with a detection limit of 0.1 μg/L.The intra-day RSD(n=6) and the inter-day RSD(n=6) were both no more than 8.6%,and the recoveries were more than 80%.With the advantages of high sensitivity,good repeatability,long-time stability and specificity,this method could be used to detect the carbamazepine in forensic and clinical analytic toxicants.