最新刊期
卷 38 ， 期 12 ， 2019
- 摘要：A comprehensive analytical method based on ultra fast liquid chromatography coupled with triple quadrupole/linear ion trap tandem mass spectrometry(UFLC-QTRAP-MS/MS) was established for the simultaneous determination of phenylethanoid glycosides,lignans,flavonoids and phenolic acids in Forsythiae Fructus.Conditions for the herbs extraction were optimized by the response surface method(RSM).Subsequently,the extract was separated on an XBridge-C18 column(4.6 mm×100 mm,3.5 μm) by gradient elution with 0.1% aqueous formic acid solution-acetonitrile as mobile phase at a flow rate of 0.8 mL/min at 30 ℃,and analyzed under multiple reaction monitoring(MRM) mode.Results showed that,the optimum sample extraction conditions were as follows:72% of methanol volume fraction,38∶1 mL/g of liquid to material ratio and 60 min of extraction time.Additionally,the 21 analytes showed good linearities in corresponding concentration ranges with their correlation coefficients(r) no less than 0.999 0.The limits of detection and the limits of quantitation were 0.001-233.710 ng/mL and 0.002-771.250 ng/mL,respectively.The precision,repeatability and stability of the method were all satisfactory.Average spiked recoveries ranged from 98.6% to 102% with relative standard deviations(RSD) between 0.89% and 3.8%.The method developed is accurate and reliable,and provides a new reference for the quality evaluation and control of Forsythiae Fructus.关键词：Forsythiae Fructus;ultra fast liquid chromatography coupled with triple quadrupole/linear ion trap tandem mass spectrometry(UFLC-QTRAP-MS/MS);response surface method(RSM);bioactive constituents
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发布时间： - 摘要：One of challenges for current glycomic analysis is that it often requires high quantity of initial sample,which is difficult to meet the needs of micro-sample analysis.In this study,a micro-sample N-glycan preparation technique(GPAT) was developed for the release,enrichment and analysis of N glycans in micro protein samples.By loading C18 and HILIC fillers separately in tips,a one stop platform was set up to perform protein digestion,N glycan release and enrichment in situ.Compared with other N-glycome analysis based on the filter aided sample preparation(FASP) strategy,N-glycome analysis with GPAT was able to detect 20 and 39 N glycans in 10 μg IgG and 10 μg HepG2 cell proteins,respectively,realizing almost the same identification effect with 90% decrease of the initial sample consumption.Otherwise,forty nine N glycans was also detected in 10 μg of urine protein extracted from the urine of 6 healthy people(3 males,3 females).Results show that GPAT realizes a simple and fast quantitative analysis for N-glycans in micro scale protein samples,and lays a foundation for further application of glycome researches.关键词：N-glycan;glycome;urinaryprotein;MALDI-TOF MS
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发布时间： - 摘要：In order to solve the problem of poor generality of near infrared spectroscopy(NIR) model caused by the difference of measuring environment and spectroscopy instruments,a model transfer method based on wavelet transform combined with dynamic time warping(WDTW) algorithm was proposed to realize the sharing of models among different instruments.First,the infrared spectra were preprocessed with wavelet transform.Then,the best match wavelength point relationship between two spectroscopy was acquired by using WDTW algorithm to build the regression model,and the performance of the developed model transfer method was verified with the experiment built transfer model using the near infrared spectroscopy dataset from drug and gasoline samples.The spectral standard deviation of prediction(SEP) for the gasolin datasets C7,C8,C9 and C10 were 0.414 4,0.801 1,1.090 4 and 1.290 8,respectively.The spectral SEP in activity,hardness and weight components of the drug datasets were 2.585 6,0.434 5 and 2.270 3,respectively,which were lower than those of the traditional methods.The experimental results showed that the WDTW model transfer algorithm has low standard error of prediction.It could not only eliminate the difference between the master and slave machine spectroscopy,but also improve the stability and accuracy of the model.关键词：near infrared spectroscopy(NIR);model transfer;wavelet transform;dynamic time warping
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发布时间： - 摘要：A method was established for qualitative and quantitative analysis on direct coal liquefaction cycled solvent(CDLRS) by comprehensive two dimensional gas chromatography time of flight mass spectrometry with hydrogen flame ionization detector(GC×GC-TOF MS/FID).The data was acquired simultaneously by TOF MS and FID detector.The acquired data by GC×GC-TOF MS were qualified based on NIST library search,standard material retention value comparison,spectral analysis,standard mass spectrum comparison,two dimensional spectral features and extracting compound molecular ions,and then divided into 18 categories based on z value.Afterwards,the Chroma TOF 47 was used to apply the qualitative classification results of TOF MS to the FID detection data,and the data collected by TOF MS and FID were normalized by the chromatographic peak area to realize semi quantitative analysis of CDLRS.The quantitative results of GC×GC/FID showed that saturated hydrocarbons and aromatic hydrocarbons in the CDLRS accounted for 45.805% and 53.938%,respectively.The saturated hydrocarbons were mainly dicycloalkanes and tricycloalkanes,which contents were 14.644% and 18.021%,respectively.The aromatic hydrocarbons were mainly cycloalkylbenzenes and dinaphthenebenzenes,which accounted for 19.759% and 16.528%,respectively.This method provided an effective analytical means for the qualitative and quantitative analyses of CDLRS.关键词：coal direct liquefaction cycle solvent;comprehensive two dimensional gas chromatography-time-of-flight mass spectrometry with hydrogen flame ionization detector;qualitative and quantitative analysis
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发布时间： - 摘要：A Fourier transform ion cyclotron resonance mass spectrometric(FTICR-MS) method was developed for the simultaneous and rapid determination of four lysophosphatidylcholine(LPCs) in complex biological samples.The biological sample was ultrasonically extracted with methanol-chloroform(9∶ 1,by volume) for 30 min,and filtered with a 0.22 μm filter membrane for analysis.FTICR-MS determination were performed in direct infusion injection mode,using a 250 μL microsampler at a flow rate of 120 μL/h.MS spectra were recorded in a mass to charge ratio(m/z) range of 50-1 000 under positive ion electrospray ionization(ESI) mode.Quantitative analysis was conducted by the external standard method.Results indicated that the four investigated LPCs showed good linearity in the concentration range of 0.5-100 μg/L,with correlation coefficients(r2) not less than 0.993 0.The limits of detection and quantitation were in the ranges of 0.02-0.03 μg/L and 0.07-0.1 μg/L,respectively.The average recoveries of four LPCs from plasma and rat liver samples at three spiked levels ranged from 70.8% to 95.0%,with relative standard deviations(RSD) of 1.2%-98%.The developed method showed the advantages of simplicity,rapidness,sensitivity,accuracy and good repeatability,and was suitable for the rapid determination of LPCs in complex biological samples.关键词：Fourier transform ion cyclotron resonance mass spectrometry(FTICR-MS);lysophosphatidylcholines(LPCs);biological samples
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发布时间： - 摘要：In the current study,the nano Ag sol of grass carp scale collagen(Col-nAg sol) was prepared by chemical reduction method,using silver nitrate solution with tea polyphenols(TP) as reducing agent and while collagen of grass carp scale as stabilizer.Effects of AgNO3 concentration,TP concentration and pH value on the preparation of Col-nAg sol were studied.Results showed that the optimal preparation conditions for Col-nAg sol were as follows:0.02 mol/L for AgNO3,pH 7.0 and 2 mol/L for TP.The average particle size for nano-Ag was 4.45 nm,which could be preserved at 4 ℃ for 60 days without obvious change.The Col-nAg sol was applied in the detection of Cr3+.Non-crosslinking agglomeration occurred between the nano-Ag particles and Cr3+,which caused a dramatic color change of Col-nAg sol from yellow to brown and a larger particle size of nano silver.The method was highly selective and sensitive in the detection of Cr3+ with a detection range of 0-10 μg/mL and a detection limit of 0.5 μg/mL.Parameters such as detection time,temperature and pH were optimized to obtain precise detection limit.关键词：nano-Ag sol of grass carp scale collagen;Cr(Ⅲ);tea polyphenols;water;stability
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发布时间： - 摘要：An ultrahigh performance liquid chromatography-quadrupole-time of flight-mass spectrometric(UPLC-Q-TOF-MS) method was established for the qualitative analysis of impurities in orlistat hydrogenation solution.The isocratic elution was performed on a Thermo Hypersil gold aq C18 column(2.1 mm×150 mm，1.9 μm) with 0.1% acetic acid aqueous solution-0.1% acetic acid acetonitrile(25∶75) as mobile phase.The MS was operated with an electrospray ionization(ESI) source in positive ion mode within a sanning range of m/z 50-600.The nebulizing temperature was set at 300 ℃ and the dry gas flow was 10 L/min.The exact mass and fragmentions of 16 impurities were acquired by Q-TOF-MS after separation by UPLC.Structures of the impurities were analyzed and their originations were deduced.More than 0.1% impurities in orlistat hydrogenation solution were generated mainly in the process of fermentation,which need be purified in the next procedure.The results obtained provided a reference for the optimization of manufacturing process and quality control of orlistat.关键词：ultrahigh performance liquid chromatography-quadrupole-time of flight-mass spectrometry;orlistat hydrogenation solution;structures of impurities;originations of impurities;fermentation
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发布时间： - 摘要：A liquid chromatography-tandem mass spectrometric(LC-MS/MS) method was developed for the detection of three brevetoxins,i.e.BTX-1,BTX-2 and BTX-3 in seawater based on liquid-liquid extraction.The analysis volume of seawater was reduced to 20 mL by using LC-MS/MS.The extraction conditions for three brevetoxins in seawater optimized with response surface were as follows:sodium chloride:6 g,vortex time:60 s,extraction solvent:5 mL ethyl acetate;and extraction times:twice.The linear ranges of three brevetoxins were all 1-200 μg/L,their limits of detection and quantitation were 0.02 μg/L and 0.05 μg/L,respectively.The average recoveries for three brevetoxins ranged from 95.4% to 104%,with intra-day and inter-day relative standard deviations(RSD) of 2.2%-5.3% and 3.0%-4.5%,respectively.With low consumption and high pretreatment efficiency,this method realizes the rapid analysis on trace of brevetoxins in seawater.关键词：liquid-liquid extraction;liquid chromatography-tandem mass spectrometry(UPLC-MS/MS);seawater;brevetoxin
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发布时间： - 摘要：A method was developed for the determination of 3-chloro-1,2-propanediol dipalmitate(3-MCPD-DP) in oil by solid phase extraction/liquid chromatography-tandem mass spectrometry.Oils sample was directly dissolved with acetonitrile-isopropanol(1∶1,by volume),and purified with manual-filled PSA+C18 solid phase extraction column.Separation of the analyte was performed on a ThermoFisher Accucore C18 column by gradient elution,using 10 mmol/L formic acid methanol solution and 10 mmol/L ammonium isopropanol solution as mobile phases.The detection was performed by LC-MS/MS in positive electrospray ionization(ESI+) mode under multiple reaction monitoring(MRM) mode,and the quantitative analysis was carried out by the internal standard method.Effects of ionization,content of solid phase extraction(SPE) filler,elution and solution with constant volume were investigated.Under the optimal conditions,the calibration curve for 3-MCPD-DP was linear in the range of 0.5-1 000 ng/mL with a correlation coefficient(r2) more than 0.999.The limit of detection(LOD,S/N≥3) and the limit of quantitation(LOQ,S/N≥10) were 0.025 mg/kg and 0.050 mg/kg,respectively.Average recoveries for 3-MCPD-DP at spiked levels of 0.1-0.5 mg/kg varied from 90.8% to 102% with relative standard deviations(RSD,n=6) of 1.1%-3.0%.The method is simple and sensitive,and is suitable for the detection of 3-MCPD-DP in oils.关键词：solid phase extraction(SPE);liquid chromatography-tandem mass spectrometry(LC-MS/MS);oil;3-chloro-1,2-propanediol dipalmitate(3-MCPD-DP)
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发布时间： - 摘要：A capillary gas chromatographic column with Nafion film as stationary phase was prepared via a verified dynamic coating procedure.The separation performance of the Nafion film coated capillary column was studied with linear alkanes,linear alcohol,pinene isomer and aromatic isomer,and its morphology was analyzed by SEM.Results showed that the column could offer effective separations for linear alkanes,terpene isomer as well as aromatic positional isomer.Effect of temperature on separation of terpene isomer and aromatic positional isomer was investigated,which was used to elucidate that the separation process for aromatic positional isomer was controlled by both entropy and enthalpy,but the separation process for terpene isomer was controlled only by enthalpy.关键词：nafion film;GC;aromatic positional isomer;separation
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发布时间： - 摘要：Manganese is one of the essential trace elements in human body,but excessive intake of manganese may cause poisoning and even death.Therefore,it is of great significance to develop a new method for detection of manganese ions,which is low cost,high sensitive and easy to operate.A kind of bipolar tetradentate host ligand bis salophen was synthesizd with salicylaldehyde and 3,3′-diaminobenzidine and self assembled with 3,3′ diaminobenzidine as a guest ligand to form a bis-salophen supramolecular polymer which was used in the detection of Mn2+ by resonance light scattering(RLS) technique.The morphologies of manganese ions under different acidity were simulated by using a software Visual Minteq.Experimental results showed that under the optimized conditions of Tris-HCl buffer solution,acidity of pH 7.5,reaction temperature of 20 ℃ and reaction time of 15 min,there was a good linear relationship between RLS intensity and concentration of manganese ions in solution,with a correlation coefficient(r) of 0.999 4,a linear range of 0.4-60 nmol/mL,a linear regression equation of IRLS=270.64 c(nmol/mL)+1 530.21.The limit of detection was 0.13 nmol/mL.The bis-salophen supramolecular polymer was successfully applied in the detection of manganese ions in Xiangjiang River water and domestic water.关键词：supramolecular polymer;resonance light scattering;manganese;coordination chemistry;self-assembly
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发布时间： - 摘要：A novel method of high performance liquid chromatography with pH dependent fatty acid based dispersive liquid-liquid microextraction was proposed for the determination of three polycyclic aromatic hydrocarbons(PAHs),ie.phenanthrene，pyrene and acenaphthene.The parameters affecting the extraction efficiency were optimized.Under the optimum conditions of 55 μL n-heptanoic acid,50 μL 28%(mass percentage) NH4OH,500 μL 98%(mass percentage) H2SO4 and 3 min of centrifugation,three PAHs in water samples such as tap water,well water and sea water were determined by isocratic elution of acetonitrile-water.Results indicated that the calibration curves for three PAHs were linear in the range of 20-500 μg/L with correlation coefficients not less than 0.999 3 and detection limits(S/N=3) of 9.18-13.11 μg/L.The spiked recoveries for the analytes at three spiked levels were in the range of 87.9%-110% with relative standard deviations(RSD) not more than 3.0%.This method realized the enrichment and detection of PAHs with fatty acid as extractant.The method was simple and rapid,and was applied in the quantitative determination of PAHs in water samples within only 6 min.关键词：polycyclic aromatic hydrocarbons(PAHs);n heptanoic acid;dispersive liquid-liquid microextraction;high performance liquid chromatography(HPLC)
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发布时间： - 摘要：A molecularly imprinted fluorescence sensor was prepared for the selective determination of the pyrethroid pesticide metabolite 3-phenoxybenzaldehyde.Fluorescent molecularly imprinted polymers were successfully synthesized by sol-gel method on the surface of Mn doped ZnS quantum dots,with 3-phenoxybenzaldehyde as template molecule,3-aminopropyl triethoxysilane and tetraethyl orthosilicate as functional monomer and cross linker,respectively.The polymers were characterized by infrared spectroscopy,X-ray diffraction and X-ray photoelectron spectroscopy,and the detection conditions were optimized.Results showed that under the optimal conditions,the linear response range for the fluorescence sensor to 3-phenoxybenzaldehyde ranged from 0.3 μmol/L to 5 μmol/L,with a detection limit of 0.267 μmol/L.Combined with the enzymatic hydrolysis process of pesticides,this molecularly imprinted fluorescence sensor could be used in the rapid detection of pyrethroidpesticides.Results indicated that recoveries for 3-phenoxybenzaldehyde were in the range of 84.0%-119%,with the relative standard deviations not more than 5.0%.The prepared molecularly imprinted fluorescence sensor could be used for the determination of 3-phenoxybenzaldehyde in food.关键词：molecularly imprinted polymers;fluorescent sensor;3 phenoxybenzaldehyde;pyrethroid pesticide;quantum dots
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发布时间： - 摘要：A method of high performance liquid chromatography with hollow fiber-based liquid phase microextraction(HF-LPME/HPLC) was developed for the analysis of four trace cephalosporin antibiotics,i.e.cefazolin(CZO),cefuroxime(CXM),ceftazidime(CAZ) and cefoxitin(FOX) in water.The optimized conditions were as follows:1-octyl-3-methylimidazolium hexafluorophosphate(［Omin］PF6) added with 10% trioctylphosphine oxide(TOPO) was selected as extraction solvent,in which TOPO was used for assisted extraction.The pH of sample solution was adjusted to 2.5.The extraction was conducted for 20 min at 30 ℃,with a stirring rate of 600 r/min.Four cephalosporin antibiotics were separated within 7 min on an Agilent Poroshell 120 EC-C18 column(100 mm×4.6 mm,2.7 μm) using 0.05 mol/L sodium acetate buffer(pH 4.0)-acetonitrile(9∶1,volume ratio) as mobile phase.Results showed that there were good linear relationships for four cephalosporin with the enrichment factors of 45-78 and the limits of detection(LOD) of 0.2-0.7 ng/mL.Recoveries for the four analytes ranged from 83.2% to 102%,with relative standard deviations(RSD) of 2.0%-9.8%.With the advantages of simple operation,high efficiency,low cost,low solvent consumption,environmental protection and high sensitivity,the proposed method was suitable for the determination of four trace cephalosporin residues in water.关键词：hollow fiber based liquid phase microextraction;ionic liquid;high performance liquid chromatography;cephalosporin;water
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发布时间： - 摘要：A method of high performance liquid chromatography-inductively coupled plasma mass spectrometry(HPLC-ICP-MS) with online enrichment was established for the determination of ultra trace migration of hexavalent chromium in toy materials.The hexavalent chromium in the sample was firstly concentrated with an Agilent BIO WAX NP5 anion exchange column(4.6 mm×50 mm,5 μm) using 10 mmol/L ammonium nitrate as mobile phase,then transfered to a Dionex AG7 anion column(4.0 mm×50 mm,10 μm) through a valve switching,separated by elution with 75 mmol/L ammonium nitrate,and finally analyzed by ICP-MS.The on line enrichment time was set at 4 min,the injection volume was 900 μL,the flow rate in enrichment path was 0.4 mL/min,and the off flow rate was 0.6 mL/min.Results showed that there was a good linearity for hexavalent chromium in the range of 2-20 ng/L,with a detection limit of 1.93 ng/L and a relative standard deviation(RSD) of 3.9%.Compared with the conventional sample injection,this method had an about 8.1 times higher enrichment factor with enrichment efficiency of 90%.Samples from three categories of toy materials according to Directive 2009/48/EC of the European Parliament and of the Council of 18 June 2009 on the Safety of Toys were spiked at 5 ng/L and 10 ng/L,and recoveries for hexavalent chromium were in the range of 93.4%-111%.关键词：online enrichment;high performance liquid chromatography;inductively coupled plasma mass spectrometry;migration of hexavalent chromium;ultra trace;toy materials
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发布时间： - 摘要：A method for the determination of chloramphenicol in cosmetics was developed using direct real time analysis-high resolution mass spectrometry.The sample was ultrasonically extracted with ethanol,then diluted 1∶1 by volume with water,and finally injected with a 12 Dip-it Samplers.The instrument parameter were optimized to obtain the sensitive and accurate determination for chloramphenicol.At a sample introduction rate of 0.3 mm/s,high intensity of ［M-H］-ions for chloramphenicol were observed in the negative ion and Full MS-PRM mode by utilization of high purity helium gas at 500 ℃.The calibration curve for chloramphenicol was linear in the range of 0-100 mg/L with a correlation coefficient of 0.998 4.The limit of quantitation(LOQ) of the method was 3.0 mg/kg.Recoveries for chloramphenicol at three spiked levels of 3.0,6.0,30 mg/kg were in the range of 70.2%-119%,with relative standard deviations(RSD) of 8.4%-17%.With its rapid analysis,simple pretreatment steps and low matrix interference,the method was suitable for the rapid determination of chloramphenicol in cosmetics.关键词：direct analysis in real time;high resolution mass spectrometry;cosmetics;chloramphenicol;rapid determination
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发布时间： - 摘要：A new method of imprinting lithography for processing paper based microfluidic chip was developed in this paper.The filter paper used in the study was soaked in the hexane solution containing alkylketone dimmer(AKD),and the triethanolamine solution was used as the blocking reagent.Painter software was applied to design chip pattern and make photosensitive stamp,which was then printed on the surface of the filter paper in accordance with the designed pattern.After the filter paper was heated in 105 ℃ oven for over 10 min,the non imprinted area was hydrophobic,and the imprinted area was hydrophilic.Thus,a liquid flow channel was formed.Influences of concentration of hydrophobic agent,selection and proportion of the blocking reagent and imprinted resolution on the property of paper based microfluidic chips were investigated.The prepared paper based microfluidic chips were used in colorimetric analysis of sodium nitrite solution,and a good linear relationship was obtained.Comprehensive experimental analysis results showed that,with low cost,simple operation and fast analysis,the method has a wide application prospect in production of inexpensive and easily popularized paper chips.关键词：paper-based microfluidic;imprinting method;photosensitive stamp mark;alkylke tene dimmer
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发布时间： - 摘要：A method of gold nanoparticle based nucleic acid aptamers was developed for the visual inspection of organic phosphorus in Chinese herbal medicines.The nucleic acid aptamers were fabricated by using a broad spectrum aptamer specifically binding to specific organophosphorus pesticide as recognition element and nano gold particles as signal transduction element,immobilizing the former on the surface of the latter to construct four organic substances.Therefore,an organophosphorus aptamer was constructed for the multi residue detection of organophosphorus in Chinese herbal medicines.The solution system changes from red to blue as the residual amount of four organic phosphorus exceeds 1 000 μg/L,which could achieve the effect of rapid detection with the naked eye.With simple operation,good specificity and intuitive detection,the method is suitable for on site rapid detection of four organophosphorus pesticides in Chinese herbal medicines.关键词：AuNPs;organophosphorus;aptamer;visual inspection
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发布时间： - 摘要：Cosmetics have become an indispensable daily used consuming product in modern society.In recent years,with peoplesincreasing awareness and pursuit of the concepts of nature,green,safety and health,the natural cosmetics with botanical active ingredients are attracting more and more attention of consumers.Compared with traditional cosmetics,the natural cosmetics containing substances from plants could be more easily absorbed by the skin without any deposition in the body.This paper introduces the plant raw material ingredients that have been used in cosmetics,and summarizes related detection technologies which may provide theoretical guidance and technical support for the effective utilization of plant resources and the inspection and testing of cosmetics.关键词：cosmetics;plant raw material ingredients;detection technology
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发布时间： - 摘要：Graphene based materials including graphene,graphene oxide,reduced graphene oxide and graphene quantum dots are a new kind of multifunctional carbon nanosubstances with sigle layer structures.And their unique physicochemical properties such as specific surface area,remarkable thermal and chemical stability,strong electrostatic stacking property,hydrophobic interaction and hydrogen bond make them have a broad prospect in separation science.Research progress of graphene based materials in capillary electrophoresis(CE) in recent years are reviewed,such as additives of background electrolyte,stationary phases of capillary electrochromatography column,modification material of electrode for CE-electrochemical detection and adsorbents in sample pretreatment for CE.The future development and potential application of graphene based materials in CE are also discussed in this review.关键词：graphene-based material;capillary electrophoresis;capillary electrochromatography;electrochemical detection;sorbent
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