最新刊期
卷 32 ， 期 6 ， 2013
- 摘要：The development of rapid and simple test is needed in order to capably monitor the frying oil quality and ensure the fried food safety.In this paper，the evolution of several analytical indicators（e.g.acid value，viscosity，absorbance values and TPC content） and the low field Nuclear Magnetic Resonance（LF-NMR） T2 relaxation characteristics （the relaxation time:T21，T22，T23，the corresponding peak area:S21，S22，S23 and the single component relaxation time:T2W） of soybean oil were studied during the frying process of no foodstuff or potato chips（180±5 ℃ for 36 h）.The multiple regression analysis method was used to establish the correlation model between LF-NMR results and the analytical indicators.At last，the developed models were experimentally verified.The results indicated that the acid value，TPC content and S21 increased linearly，while T21，T22 and T2W decreased linearly，as the frying process prolonged.And a good binomial relationship was obtained between the viscosity or absorbance values and the frying time（r2＞0.90）.No obvious relationship was found between frying time and T23，S22 or S23 .Compared with no foodstuff frying，the acid value，viscosity，TPC content，absorbance values and S21 during potato chip frying process increased significantly，while T21，T22 and T2W obviously shortened （P<0.05）.Multiple regression analysis showed that both acid value and TPC content had a good relationship with T2W and T21，and viscosity had a good linear relationship with T2W，while absorbance had a good logarithmic relationship with S21（r2＞0.93）.These models were successfully verified and could be used to predict the variations of physical and chemical indicators by the LF-NMR characteristics of the frying oil.关键词：soybean oil;frying duration;analytical indicator;LF-NMR;relaxation characteristic
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发布时间： - 摘要：The volatile components of Maillard reaction productions in chicken bone extract （MRPs1） and Maillard reaction productions in the enzymatic hydrolysate of chicken bone extract （MRPs2） were analyzed using solid phase microextraction coupled with gas chromatography-mass spectrometry（SPME/GC-MS） and Electronic Nose（E-Nose）.Total of seventy-seven volatile compounds were identified in the two kinds of Maillard reaction prdouctions （MRPs）,including 18 alcohols,23 aldehydes and ketones,3 acids,10 esters,7 heterocyclic and 16 other compounds.Among them，26 commonly substances were identified in both of the two kinds of MRPs,such as 2-furanmethanol,2-methyl-3-furanthiol,1-nonanol,dodecanal,octanoic acid,etc.The relative contents of aldehydes and ketones in the MRPs2 were greater than those in the MRPs1,but the esters were in the majority of the MRPs1.Those compounds,e.g.,（E）-2-octen-1-ol,（6Z,9Z）-pentadecadien-1-ol，benzaldehyde,octanal,6-methyl-5-hepten-2-one,2-ethyl-3-hydroxy-4H-pyran-4-one,2,3,5-trimethyl-6-ethylpyrazine,2-［（methyldithio）methyl］-furan,constituted the characteristics of aroma components of the MRPs2 and γ-dodecalactone was the characteristic flavor of the MRP1.Besides the relatively content of 4-methyl-5 thiazoleethanol was high in both MRPs（but MRP1＜MRP2）-Total relative contents of those compounds，such as 2-furanmethanol,2-methyl-3-furanthiol,3-ethyl-2,5-dimethyl-pyrazine,3,5-diethyl-2-methyl-pyrazine,2,3-diethyl-5-methyl-pyrazine,2-pentyl-furan,constituted-the characteristics of aroma components of meat flavor,however，was relatively lower in the MRPs1.That may be one of the main reasons for the different flavor between the two kinds of MRPs，and this result was also confirmed by the Electronic Nose.At the same time,it also demonstrated that enzymatic hydrolysis had a great influence on the flavor components of Maillard reaction productions.The results of this study could provide a theoretical reference for the development of chicken bone extract and its flavor seasonings.关键词：chicken bone extract;enzymatic hydrolysate;Maillard reaction;volatile components;SPME/GC-MS;E-nose
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发布时间： - 摘要：Vitamin E octenylsuccinate（VE-OS ester），obtained from the esterification of VE and octenylsuccinic anhydride（OSA），was used for the structure identification by infrared spectroscopy（IR） and nuclear magnetic resonance（NMR）.New absorption peaks at 1 860，1 776,1 755 cm-1 were found in IR，suggesting that the structure of the carboxylic acid ester extsts.1H NMR spectrum showed that the hydroxy group of VE was substituted because of the disappearance of the signal of hydroxyl group.The signal of H-9 distributed at 3.05 ppm and 3.20 ppm，and C-11 and C-12 had four peaks at 170-180 ppm in 13C NMR spectrum，showing that VE-OS ester had two isomers（a and b），and isomer a was formed easier after the analysis of NMR integrals.Using density functional theory（DFT） B3LYP/6-311++g** calculation，the configurations of VE-OS ester were optimized，and the results implied isomer a is more stable than b，which agreed well with the analysis data.Different high performance liquid chromatographic（HPLC）methods were also compared for quantitative analysis of VE-OS ester.关键词：vitamin E octenylsuccinate（VE-OS ester）;infrared spectroscopy（IR）;nuclear magnetic resonance（NMR）;density functional theory（DFT）;high performance liquid chromatography（HPLC）
- 1986
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- 1173
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- 1
发布时间： - 摘要：An analytical method was established for the determination of β-agonists（e.g.terbutaline，salbutamol，cimbuterol，ractopamine，clenbuterol，brombuterol，mabuterol）residues in animal tissue by ultra high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry（UHPLC-Q-TOF-MS）.The samples were extracted with ammonium acetate，and determined by UHPLC-Q-TOF-MS after solid phase extraction.By software，the targeted compound was confirmed by the diff between theoretical accurate relative molecular mass（Mr） and the actual accurate Mr，element composition analysis，retention time，isotopic abundance model and product ion characteristics.The result indicated that the average recoveries were in the range of 75%-114% with relative standard deviations of 4.5%- 20.6%.The calibration curves were linear in the ranges of 0.4-40.0 μg/kg for clenbuterol，and 0.2-40.0 μg/kg for the rest of the compounds，with correlation coefficients of 0.991 4-0.999 9.The limits of quantitation were 0.4 μg/kg for clenbuterol and 0.2 μg/kg for the other compounds.关键词：ultra high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry（UHPLC-Q-TOF-MS）;β-agonists;solid phase extraction
- 2500
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- 8
发布时间： - 摘要：Based on the isostere theory and the structure of alkaloid crytolepine,5-N-methylbenzofuro［3,2-b］quinoline scaffold was designed.Referencing to the derivatization strategy of amsacrine,a series of aniline-substituted 5-N-methylbenzofuro［3,2-b］quinoline derivatives were designed and synthesized,and their structures were characterized by MS and 1H NMR spectra.The binding constants and docking sores of these derivatives with double-stranded DNA were studied by UV-Vis absorption spectra and Surflex-Dock.Surface binding mode was eliminated by ionic strength influence assay.Combined with the results from EB displacement experiments,it was proposed that these derivatives interacted with duplex DNA via intercalation binding mode.关键词：benzofuro［3,2-b］quinoline;double-stranded DNA;UV-Vis absorption spectra;molecular docking;EB displacement
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- 0
发布时间： - 摘要：A liquid chromatography-ion trap-time of flight mass spectrometric（LCMS-IT-TOF）method for the determination of 9 acidic dyes in soy sauce and spice condiments such as chilli sauce,dried pimiento and chinese prickly ash was established.The samples were extracted with methanol-water（80∶20）solution and cleaned on a weak anion exchange solid phase extraction column（Oasis WAX）.The separation of target compounds was carried out on a Shimadu Shim-pack XR-ODS（2.0 mm×100 mm，2.2 μm） column using 10 mmol?L-1 ammonium acetate-methanol as mobile phase by gradient elution at a flow rate of 0.2 mL?min-1. The identification of the analytes was achieved in negative ion mode with electrospray ionization source and the quantification was carried out by the external standard method.The results showed that the matrix-matched calibrations of 9 acid dyes had good linear relationships in the certain concentration ranges with their correlation coefficients（r2） more than 0.99.Average recoveries of the acidic dyes at three spiked levels ranged from 64.8% to 106.0% with relative standard deviations（RSD,n=5）no more than 6.7%.The proposed method was simple,rapid and highly sensitive.According to the multi-stage mass spectrometry data,the accuracy of qualitative analysis by the method was improved.The method was suitable for the simultaneous determination of acidic dyes residues in soy sauce and spice condiments.关键词：liquid chromatography-ion trap-time of flight mass spectrometry（LCMS-IT-TOF）;acidic dyes;condiment
- 1949
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- 990
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发布时间： - 摘要：Au nanoparticles(AuNPs）,Nafion and electrochemical reduced graphene oxide(ERGO） were modified onto the surface of a glassy carbon electrode(GCE） by one-step electrochemical co-reduction to fabricate a modified electrode of AuNPs/Nafion/ERGO/GCE.Scanning electron microscopy(SEM） was used to characterize the electrode.The electrocatalytical behaviors of the modified electrode towards hydroquinone(HQ） were investigated by cyclic voltammetry(CV） and differential pulse voltammetry(DPV）.Experimental parameters were optimized.A good linear relationship between oxidation peak current of HQ and its concentration was obtained in the range of 2.0-100 μmol/L and 100-80 μmol/L ，with a detection limit of 0.3 μmol/L.This fabricated electrode was successfully applied in the determination of HQ in real samples.关键词：electrochemical co-reduction;Au-nanoparticles;graphene;hydroquinone
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- 1306
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- 9
发布时间： - 摘要：A high performance liquid chromatography-mass spectrometric（HPLC-MS/MS） method was proposed for the determination of 6 anti-obesity chemical drugs（sibutramine，N-di-desmethyl sibutramine，fenfluramine，phenolphthalein，rimonabant，orlistat）added illegally into health foods.The conditions of extraction procedures and the parameters of HPLC-MS/MS were optimized.The drugs were extracted with methanol，and separated on a C8 chromatographic column using a mixture of acetonitrile and 10 mmol/L ammonium acetate solution as mobile phase with gradient elution.The detection of 6 targeted compounds was performed by positive-ion electrospray ionization mass spectrometry（ESI MS） under multiple reaction monitoring（MRM） mode.Good linearities for 6 compounds were obtained in the range of 0.001-0.5 mg/L with correlation coefficients greater than 0.999.The spiked recoveries were in the range of 81%- 100%with RSDs of 4.8%-6.9%.The detection limits of these drugs were up to 0.5 μg?L-1.The results indicated that this method was simple，rapid and accurate，and was successfully applied in the examination of examine chemical drugs illegally added in the dietary supplement.关键词：weight-loss chemical drugs;high performance liquid chromatography-tandem mass spectrum（HPLC-MS/MS）;functional foods
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发布时间： - 摘要：An ion chromatographic method with direct conductivity detection for the determination of N-methyl，ethyl morpholinium cation（［MEMo］+），N-methyl，propyl morpholinium cation（［MPMo］+） two morpholinium ionic liquid cations was developed using a cation-exchange column and ethylenediamine-acetonitrile as mobile phase.The effects of column type，mobile phase and column temperature on retention and separation of the cations were investigated.The retention rules of the cations under different chromatographic conditions were formulated.The results indicated that the retention process of morpholinium cations retained in line with the ion-exchange mode，wihich was an exothermic process.The successful separation of the two morpholinium ionic liquid cations was achieved using the optimized mobile phase of 0.1 mmol/L ethylenediamine-0.5% acetonitrile（adjusted to pH 5.0 with hydrochloric acid） at a flow rate of 1.0 mL/min and a column temperature of 30 ℃.Under the optimal conditions，the two morpholinium ionic liquid cations could be successfully separated in 4 min.The detection limits（S/N=3） for ［MEMo］+ and ［MPMo］+ were 0.08 mg/L and 0.13 mg/L，respectively.The relative standard deviations（RSDs，n=5） of the chromatographic peak areas for the cations were no more than 1.5%.The method was successfully applied in the determination of morpholinium bromide ionic liquid samples synthesized by chemistry laboratory.The recoveries of morpholinium cations after spiked were in the range of 94.0%-106.0%.The method was proved to be accurate，reliable and rapid，and could meet the requirements for quantitative analysis of morpholinium ionic liquid samples.关键词：ionic liquids;morpholinium cations;ion chromatography;conductivity detection;ethylenediamine
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发布时间： - 摘要：A high performance liquid chromatography-tandem mass spectrometric（HPLC-MS/MS） method was established for the determination of ciguatoxin in deep sea fish．The residues in fish were extracted with methanol-hexyl hydride（4∶1），and purified by an HLB SPE column.The detection of ciguatoxin was performed by mass spectrometry with electrospray in positive ionization mode and multiple reaction monitoring（MRM） mode.No significant matrix effect was found for the spiked samples after purification．The recoveries of ciguatoxin in food were in the range of 70%-84% at spiked levels of 0.01-0.1 μg/kg．The relative standard deviations（RSDs） were less than 7%．The limits of detection（LOD） and the limits of quantitation（LOQs） were 0.01 μg/kg and 0.02 μg/kg，respectively．This method was simple,rapid and reliable,and could meet the requirement for determination of ciguatoxin in deep sea fish．关键词：high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）;ciguatoxin;deep sea fish
- 2855
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- 1142
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- 2
发布时间： - 摘要：A reliable，sensitive and selective method was developed for the determination of 4 macrolide antibiotics（MLs） in typical waste water and activated sludge using high performance liquid chromatography-electrospray ionization tandem mass spectrometry（HPLC-ESI-MS/MS）.The target antibiotics in water samples were enriched and cleaned up with HLB solid phase extraction cartridges，and then eluted with 6 mL methanol.The activated sludge sample was ultrasonically extracted with a mixture of acetonitrile-phosphate buffer.The eluate was collected and concentrated under a gentle stream of nitrogen gas.The target compounds were separated on a Waters Symmetry-C18 column with acetonitrile-10 mmol?L-1 ammonium acetate as mobile phase，and analyzed by HPLC-ESI-MS/MS under positive electrospray ionization and selected reaction monitoring mode.Good linearities of 4 MLs were achieved over the concentration range of 0.1-100 μg?L-1，with correlation coefficients above 0.99.The overall recoveries of 4 MLs in waste water and activated sludge matrices were in the ranges of 70.2% -90.6% and 75.6% -88.7%，respectively，with relative standard deviations（RSD，n=6） of 2.7%-7.8 %.The method detection limits of 4 MLs in water samples and activated sludge were in the ranges of 0.013-0.025 ng?L-1 and 0.09-0.22 ng?g-1，respectively.The developed method was applied in the analysis of the typical waste water and activated sludge in Shihezi，Xinjiang,and the results indicated that the target antibiotics were detected in all samples.关键词：HPLC-ESI-MS/MS;USE;SPE;macrolide antibiotics;waste water;activated sludge
- 1966
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- 1085
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- 2
发布时间： - 摘要：A gas chromatography-mass spectrometric（GC-MS） method was developed for the rapid determination of sesamol（SM） in food flavors.In order to disperse sample matrix into extraction solvent，samples were distributed by use of a vortex mixer，and then extracted with an ultrasonic generator.The effects of solvent type，solvent consumption and ultrasonic time on extraction efficiencies of target compounds were discussed.The appropriate internal standard was selected.The characteristic ions and their abundances were determined.Under the optimal conditions，the calibration curve of SM was linear in the range of 0.1-4.0 mg/L with a correlation coefficient of 0.999 9.The recoveries of SM at different spiked levels were in the range of 97%-104%，with relative standard deviations of 1.2%-3.9%.The detection limit and quantitation limit for SM were 0.26 mg/kg and 0.88 mg/kg，respectively.The result showed that the method was simple，rapid，sensitive and accurate，and was suitable for the rapid determination of SM in food flavors.关键词：gas chromatography-mass spectrometry（GC-MS）;sesamol（SM）;food flavors
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发布时间： - 摘要：Novel magnetic molecularly imprinted polymers(M-MIPs） were prepared using Sudan Ⅰ as template by molecularly imprinting technique.The morphology,composition and magnetic properties of magnetic nanoparticles were characterized by scanning electron microscope,infrared spectroscopy and vibrating sample magnetometer.The Scatchard analysis showed that there were two kinds of binding sites between the imprinted polymers and the template.The apparent maximum number(Qmax） of the M-MIPs were 84.59 μmol/g and 210.49 μmol/g,respectively.The relative selectivity coefficient of M MIPs toward Sudan Ⅰ/Sudan Ⅱ and Sudan I/Sudan Ⅲ were 2.47 and 2.24,respectively,which indicated that the M-MIPs exhibited better adsorption properties and selectivity for Sudan Ⅰ.The M-MIPs were applied in the separation of Sudan I in the extracting solution of paprika.The eluant after treating with the M-MIPs was determined by HPLC.The detection limit was 0.50 μg/g.The recoveries of Sudan I ranged from 78% to 103% with RSDs of 2.8%-5.8%.关键词：magnetic polymers;molecularly imprinted;separation and enrichment;Sudan Ⅰ
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- 1405
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- 1
发布时间： - 摘要：A UV-Vis spectrophotometric method was developed for the determination of paraben ester in cosmetics.The sample spectrum was identified by establishing background spectrum library and standard spectral library，and using vector deductible model calculation.The results indicated that the method exhibited a good linearity for paraben ester in the range of 0.25-10 mg/L（r＞0.999 2）.The relative error is less 1.2% and the RSD is lower than 1.7%.The analytical results of the proposed method are similar to those obtained by the HPLC method.The method is rapid，accurate and less reagent-consuming，and could provide a feasible scheme for in situ analysis of cosmetics.关键词：vector deductible;UV-Vis spectrophotometry;paraben ester;cosmetics
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发布时间： - 摘要：A method of chromatography fingerprint of engine oil by HPLC was established.The chromatographic conditions were as follows：RP- C18 column，mobile phase：acetonitrile-water by gradient elution，detection wavelength：280 nm，column temperature：30 ℃，injection volume：10 μL.The methodological evaluation showed that the relative standard deviations（RSDs） of relative time（α） and relative area of chromatographic peaks（Sr） from common peaks were all less than 2.4%，which could meet the technical requirement of the fingerprint（less than 3%）.By further analyzing the main characteristic peaks and computing the chromatographic peaks overlapping ratios and the similarity, could be identified and evaluated the quality of engine oil.Compared with the traditional methods，this method greatly reduced the cost of trial and time，and provided a new area for the application of rapid identification and quality control of engine oils.关键词：engine oil;additive;RP-HPLC;gradient elution;fingerprint
- 1926
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- 1106
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- 1
发布时间： - 摘要：A rapid and sensitive method of pseudo reversed phase liquid chromatography（pseudo-RPLC） was developed for the analysis of caffeine in milk tea.The samples were separated on a bare silica column coupled with aqueous-rich mobile phase（pH 2.9,0.03 mol?L-1sodium formate-acetonitrile,95∶5）,and tested within 5 min.The calibration curve was linear in the concentration range of 0.2-1 000 mg?L-1 with correlation coefficient of 0.999 5.The recoveries at a spiked level of 20 mg?L-1 ranged from 98% to 103% with RSDs 1.9%-3.6%.关键词：caffeine;milk tea;rapid determination;pseudo reversed phase liquid chromatography
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- 1003
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- 1
发布时间： - 摘要：A method was developed for the quantitation of 3-nitropropionic acid in zymin by high performance liquid chromatography-tandem mass spectrometry(LC-MS/MS）.The analyte in samples was extracted with acetonitrile and the extract was purified with PSA solid phase extraction column.The separation of 3-nitropropionic acid was carried out on a Waters HSS T3 column by gradient elution using acetonitrile-water as mobile phase.The mass analyzer was performed in negative MRM mode.The result showed that the calibration curve of 3-nitropropionic acid was linear in the range of 12.5-125 μg/L with correlation coefficients more than 0993.The limit of quantitation(LOQ） was 5.0 μg/kg.The recoveries of 3-nitropropionic acid at different spiked levels ranged from 69.1% to 114.4% with relative standard deviations(RSDs） of 0.9%-8.9%.The real sample test showed that the method was simple，rapid and reliable.关键词：solid phase extraction;ultra performance liquid chromatography-tandem mass spectrometry;3-nitropropionic acid(3-NPA）;zymin
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- 3
发布时间： - 摘要：A novel compound((E）-2-［2-(4-methoxyphenyl）ethenyl］-8-acetoxyquinoline,compound 1） was prepared by the condensation of 8-hydroxyquinaldine with 4-methoxybenzaldehyde,and characterized by NMR,LC-MS and EA spectra.The crystal structure of the targeted compound was determined by X-ray single crystal diffraction.It belongs to monoclinic system with space group C2/c,a=16.375(10）?,b=19.476(12）?,c=10.571(6）?;V=3371(3）? 3，Z=8,Dc=1.258 mg /m3,R1=0.060 8,wR2=0.147 1.Based on hydrogen bonding and π…π stacking interactions,3D supramolecular structure in compound 1 was fabricated.Additionally,the fluorescent properties of the targeted compound was investigated.关键词：quinoline;synthesis;characterization;crystal structure;fluorescent property
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- 1023
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- 1
发布时间： - 摘要：A new triazene reagent，1-（2-benzothiazole）-3-（8-（5-p-sulfophenylazo）)quinolinetriazene（BTSPQT），was synthesized using 2-aminobenzothiazole and 5-p-sulfophenylazo-8-aminoquinoline as raw material，and the chromogenic reaction of this reagent with Cu2+was investigated.The results showed that BTSPQT could react with Cu2+ at room temperature in Na2B4O7-HCl buffer（pH 8.0） containing 0.3% Triton X-100 to form a purple complex with a molar ratio of BTSPQT to Cu2+ by 2∶1 and the stability constant of （2.59±0.40）×109.The maximum absorption wavelength of this complex was located at 610 nm.Based on this reaction，a new spectrophotometric method for the determination of Cu2+ was developed.Beer′s law was obeyed in this method in the concentration range of 0.025-0.40 mg/L for Cu2+ with the apparent molar absorptivity of 3.61×105 L?mol-1?cm-1.Some common metals at the concentration below 2.5 mg/L did not interfer the determination of 0.40 mg/L Cu2+.The proposed method was applied in the determination of trace copper in flour and tea samples with recoveries of 96%-103% and relative standard deviations（RSDs） less than 4.0%.关键词：1-（2-benzothiazole）-3-（8-（5-p-sulfophenylazo））quinolinetriazene;copper（Ⅱ）;spectrophotometry
- 1912
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- 1040
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- 1
发布时间： - 摘要：A method for the simultaneous determination of four tocopherols in vegetable oils by reverse phase high performance liquid chromatography（RP-HPLC） was established.The sample was extracted with methanol under ultrasonic.The chromatographic separation was carried out on a C30 column（4.6 mm i.d.×250 mm，5 μm） using fluorescence detection at 290 nm of excitation wavelength and 340 nm of emission wavelength.Methanol-water-tert-butyl methyl ether（60∶15∶25）was used as mobile phase by isocratic elution.Results showed that good linear ranges for 4 tocopherols were obtained from 0.050 mg/L to 100.0 mg/L with correlation coefficients（r2）larger than 0.999.The mean recoveries were in the range of 81.3%-93.2% at three spiked levels of 0.50，50.0，500.0 mg/kg，and the relative standard deviations（RSDs） were less than 6%.The limits of detection（LODs） were 0.10 mg/kg for α-tocopherol，0.05 mg/kg for β- and γ-tocopherol，and 0.02 mg/kg for δ-tocopherol. The method is accurate，sensitive and reliable，and could be applied in the real sample analysis.关键词：reverse phase high performance liquid chromatography（RP-HPLC）;fluorescence detection;tocopherols;vegetable oils
- 2346
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- 1249
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- 10
发布时间： - 摘要：A method was established for the simultaneous determination of vancomycin and norvancomycin residues in milk and dairy products by solid-phase extraction and ultra performance liquid chromatography coupled with tandem mass spectrometry（UPLC-MS/MS）.The sample was extracted with a mixed solution of acetonitrile and water.Then the protein was precipitated with trichloroacetic acid, the fat and other impurities were eliminated with dichloromethane.The extration solution was purified with Strata-X-C solid phase extraction（SPE） column.The target compounds were separated on a reversed phase column by gradient elution of acetonitrile and 0.1% formic acid water solution,and then detected with positive electrospray ionization under multiple reaction monitoring（MRM） mode.The SPE conditions and UPLC-MS/MS parameters were optimized.Under the optimized conditions,the calibration curves for two target compounds were linear in the range of 4-5 000 μg/L with correlation coefficients(r2) greater than 0.99.The average recoveries of blank matrix sample at three spiked levels of 15,60, 150 μg/kg were all more than 80%,and the relative standard deviations（RSDs）were less than 5%.The limits of detection（LODs）for vancomycin and norvancomycin were 0.5 μg/kg and 0.8 μg/kg,respectively.The limits of quantitation（LOQs）were 2.0 μg/kg and 3.0 μg/kg,respectively.The method was practical，accurate and sensitive,and was suitable for the determination of vancomycin and norvancomycin in milk and dairy products.关键词：UPLC-MS/MS;solid phase extraction;milk and dairy products;vancomycin;norvancomycin
- 2413
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- 1105
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- 5
发布时间： - 摘要：An isoreticular metal-organic framework（IRMOF-3） was modified with salicylaldehyde（sal） by postsynthetic modification（PSM） method.The compound was metallated with M（acac）n（M=Mg，Zn，Pr，Ni） and the characteristics of the complex of IRMOF-3-Msal were investigated by solid-state fluorescence spectroscopy.The emission peaks of IRMOF-3-Znsal exhibited the maximum blue shifted behavior and stronger relative fluorescence intensity.The further research indicated the fluorescence variations of IRMOF-3-sal metallated with M（NO3）n were better than that with M（acac）n.关键词：IRMOF-3;metal-organic frameworks;post synthetic modification;solid-fluorescence
- 1919
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- 1079
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- 0
发布时间： - 摘要：Atomic fluorescence spectrometry（AFS） has become an important means for detection of metal and metalloid.Sample introduction technique for AFS is directly related to the type of incorporated atomizer.In this paper，according to the difference of sample introduction principles，four kinds of sample introduction techniques of AFS，including direct injection，spray introduction，chemical vapor generation（CVG） and electrothermal vaporization（ETV），were reviewed respectively.The research development，principle，merit and demerit of each kind were presented in detail，particularly that for CVG and ETV.The perspective of sample introduction techniques for AFS in future was also put forword.Totally，75 references were cited.关键词：atomic fluorescence spectrometry;sample introduction technique;chemical vapor generation;electrothermal vaporization;research progress
- 1903
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- 1144
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- 1
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