最新刊期
卷 37 ， 期 1 ， 2018
- 摘要：A analytical method was developed for the simultaneous determination of fifteen rodenticides in whole blood and urine samples by liquid chromatography-tandem mass spectrometry(LC-MS/MS) with on-line solid phase extraction(on-line SPE).The samples were treated with acetonitrile,followed by dilution,centrifugation and filtration.The solution obtained was purified with a polymer column for hydrophilic-lipophilic balance(HLB),then eluted on a ZORBAX Eclipse Plus C18 column with acetonitrile and 0.01 mol/L ammonium acetate aqueous solution as mobile phase.The analytes were detected in dynamic multiple reaction monitoring(DMRM) mode under alternate positive/negative electrospray ionization(ESI+/ESI-) mode,and quantified by external standard method.The results showed that there existed good linear relationships by quadratic equation fitting for the fifteen rodenticides in whole blood and urine in the investigated mass concentration ranges with the correlation coefficients not less than 0.997 8 for whole blood and not less than 0.996 5 for urine,respectively.The LODs and the LOQs varied from 0.10 μg/L to 5.00 μg/L and 0.50 μg/L to 10.0 μg/L,respectively.The recoveries at three spiked levels in whole blood and urine ranged from 81.8% to 109.6% with their RSDs of 0.3%-3.8%(n=6).The developed method is simple and reliable,and is sensitive for the rapid detection and accurate quantification of fifteen rodenticides in whole blood and urine samples.关键词：on-line solid phase extraction(on-line SPE);liquid chromatography-tandem mass spectrometry(LC-MS/MS);rodenticides;whole blood;urine;quadratic equation
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发布时间： - 摘要：The volatile compositions of agarwood were produced by biological,chemical and physical(flame drilled) methods,then enriched by solid phase microextraction and isolated and identified by GC-MS.The quality of the agarwood produced was evaluated.Investigation showed that the volatile compositions of the agarwood were all composed of sesquiterpenoids and aromatic compounds,but the chemical compositions and contents of the agarwood were quite different because of the different artificial inducing methods.The six characteristic components,i.e.agarofuran,hinesol,4-phenyl-2-butanone,p-methoxybenzylacetone,agarospirol and baimuxinal,and their contents were used as the evaluation indexes for the agarwood quality.The content of agarospirol in the flame drilled agarwood was the highest,which was about 5.5%.The total content of characteristic components in the agarwood produced by biological method was the highest,which reached to 16.6%,followed by that of the flame drilled agarwood,which was around 13.6%,and the agarwood produced by chemical method was the lowest.The result showed the biological method has the best agarwood quality,the flame drilled method was slightly poor,and they were both superior to the chemical method.关键词：agarwood;SPME;GC-MS;volatile constituents;artificial inducing methods
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发布时间： - 摘要：In this paper,a GC-MS/MS method was established for the determination of the residue and migration amounts of six preservatives.The migration regularity of six preservatives from sample to simulated saliva and sweat was studied,and the migration rates at different times were calculated through building a self-made migration device to simulate the actual exposure scenarios.The results showed that the migration amount of preservatives gradually increased with time in range of 2 min to 96 h,and finally reached the migration equilibrium.The migration rates in saliva and sweat were in the ranges of 2.1%-61.7% and 2.2%-86.4%,respectively.It was worth noting that when the sample was in contact with the simulated solution for only 2 min,the analytes could be detected,and the migration rates in saliva and sweat were 2.1%-4.2% and 2.2%-3.3%,respectively.Some commercial samples were detected to contain 2,4-DCP and 2,4,6-TCP.Due to the characteristics of children’s daily short duration contacting with the sample,two positive samples were selected for the determination of their migration amounts and migration rates in 2-30 min.关键词：wooden children’s products;wood preservatives;migration regularity;migration rate;GC-MS/MS
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发布时间： - 摘要：In this paper,ophiopogon japonicus crude polysaccharide was extracted by hot water and ultrasonic extraction,then purified by DEAE-cellulose52 cellulose column chromatography and Sephacryl S-300 gel column chromatography.Homogeneous polysaccharide WPOJ-DS extracted with hot water and UPOJ-DS extracted by ultrasound were obtained.The structures of WPOJ-DS and UPOJ-DS were characterized by high performance liquid chromatography,gas chromatography,infrared spectroscopy,partial acid hydrolysis,methylation analysis and magnetic resonance imaging.The solution conformation of WPOJ-DS and UPOJ-DS were studied by congo red test,circular dichroism spectra and atomic force microscopy.The results showed that there were differences between WPOJ-DS and UPOJ-DS,which existed in the molecular weight,molar ratio of monosaccharide and the solution conformation,while the differences also demonstrated that the structure characterization and solution conformation could be effected by ultrasonic extraction.The main chains in both WPOJ-DS and UPOJ-DS mainly composed of →6)-D-Glcp(1→ and →3,6)-D-Glcf(1→.The structure of →6)-β-D-Glcp(1→ existed in WPOJ-DS but not in UPOJ-DS.Congo red experiment,circular dichroism spectra and chromatography and atomic force microscopy showed that there was a helix structure in UPOJ-DS but not in WPOJ-DS.In addition,the solution conformations of WPOJ-DS and UPOJ-DS were different in different environment solutions.关键词：ophiopogon japonicus polysaccharide;ultrasonic extraction;structure;solution conformation;atomic force microscopy
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发布时间： - 摘要：Upconversion nanoparticles were synthesized and modified with OTA aptamer,and gold nanoparticles were modified with complementary DNA strand(cDNA).Based these nanoparticles,a FRET aptasensor for OTA was successfully fabricated by using upconversion nanoparticles as energy donor and gold nanoparticles as energy acceptor .In the optimum conditions,this aptasensor obtained a detection limit of 0.001 ng/mL with a linear range of 0.001-10 ng/mL.The above method was applied in the detection of OTA in beer samples.At spiked levels of 0.01,0.1,1.0 ng/mL,the recoveries for OTA ranged from 100% to 119% with the relative standard deviations(RSDs) of 4.3%-4.9%.This method also demonstrated its advantages such as high sensitivity,good specificity,simplicity and low cost.关键词：upconversion nanoparticles;gold nanoparticles;fluorescence resonance energy transfer;ochratoxin A;aptamer
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发布时间： - 摘要：In this paper,a rGO/NPAN composite film modified electrode was fabricated successively by electropolymerization，adsorption,and constant potential reduction method.Then,a MnO2/rGO/NPAN modified electrode was constructed by dropping the prepared manganese dioxide on the support material consisted of reduced graphene oxide and N-substituted carboxylic polyaniline.The strong adsorption of N-substituted carboxylic polyaniline and great surface area and high conductivity of reduced graphene oxide could make manganese dioxide loaded well and improve electrocatalytic properties of the MnO2/rGO/NPAN modified electrode.The morphology of the composite film was characterized by scanning electron microscopy(SEM).In addition,the factors such as the number of NPAN electropolymerization,GO concentration,electroreduction time and pH values,were discussed in terms of electrochemical activity and electrocatalytic activity.Experimental results showed that the modified electrode had a good catalytic effect to nitrite oxidation.Compared with manganese dioxide modified electrode,the MnO2/rGO/NPAN modified electrode had a lower detection potential,higher response current and sensitivity to nitrite in the concentration range of 0.5×10-6-5.13×10-2 mol/L,with a sensitivity of 14.075 μA?(mmol/L)-1 and the detection limit(S/N=3) of 0.2 μmol/L.关键词：reduced graphene oxide;N-substituted carboxylic polyaniline;manganese dioxide;nitrite;electrochemical sensor
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发布时间： - 摘要：In this paper,based on the photoinduced electron transfer(PET) mechanism,a specific cysteine fluorescence probe was successfully synthesized.The probe molecules reacted with Cys to make nucleophilic substitution because of its strong nucleophilicity,resulting in the departure of acryl and inhibiting the PET process of probe molecular system.When adding a variety of test analytes into the probe solution,only Hcy and GSH,which have a similar structure with Cys,led to a weak fluorescence variation of probe solution,other amino acids could make no change of the fluorescence intensity.With good selectivity and sensitivity to Cys,the probe could be used to detect Cys under physiological conditions,and distinguish Hcy and GSH.Meanwhile,the probe successfully realized the fluorescence imaging of Cys in cells,and established a specific Cys recognition analysis method for practical applications in biology and medicine.关键词：cysteine;synthesis;cell imaging;fluorescence probe;specificity
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发布时间： - 摘要：A method was developed for the determination of thirteen organophosphate esters in plants by gas chromatography-ion trap tandem mass spectrometry with simultaneously accelerated solvent extraction and purification.Silica gel and active carbon were selected as the on-line purification materials,and successively put into the extracting cell.Then the plant samples were put into the cell for extraction.The accelerated solvent extraction conditions were as follows：extraction solvent：hexane-acetone(1 ∶1,by volume),the extraction temperature：100 ℃,the static extraction time：10 min,and the number of extraction cycles：2.The extract was evaporated and separated on a DB-5MS chromatographic column(30 m×0.25 mm×0.25 μm),and subsequently detected by ion trap tandem mass spectrometry under selected reaction monitoring(SRM) mode.An internal standard method was adopted for the quantitation.The recoveries obtained were in the range of 76.9%-113.0%,with the relative standard deviations of 2.0%-14.6%.The detection limits and quantitation limits of the method were in the ranges of 0.79-2.27 ng/g and 2.65-7.59 ng/g,respectively.The method is simple,rapid and accurate,and could be used for the determination of 13 organophosphate esters in plants.关键词：accelerated solvent extraction;gas chromatography-ion trap tandem mass spectrometry;plants;organophosphate esters
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发布时间： - 摘要：A novel chemiluminescent(CL) aptasensor for ochratoxin A(OTA) with magnetic beads as separate carrier was designed.Firstly,the capture DNA and OTA aptamer were immobilized on the surface of the magnetic beads,then the biotin-reporter DNA and OTA were taken to competitively bind to the OTA aptamer.Finally,streptavidin-gold nanoparticles(SA-AuNPs) and NH2OH/Au3+ were added sequencely in order to improve the sensitivity for CL detection on OTA.The effects on the experiment including magnetic beads，capture DNA，aptamers，biotin-reporter DNA and dilution multiple of SA-AuNPs,were optimized.Under the optimized experimental conditions,there existed a good linear relationship between the CL intensity(ΔCL) and the logarithms of OTA concentration(r2=0.992 5) in the range of 0.01-50 ng/mL,with a detection limit of 1.58×10-3 ng/mL.In the recovery experiments by adding different concentrations of OTA to the beer samples,the recoveries ranged from 97.4% to 105.4% with the relative standard deviations of 4.0%-5.5%.关键词：ochratoxin A;SA-AuNPs;hydroxylamine;chemiluminescence
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发布时间： - 摘要：The effects of edible/industrial gelatin concentrations,mixing ratio and sucrose or sodium chloride(NaCl) solutions on viscosity,gel strength and low-field nuclear magnetic resonance(LF-NMR) relaxation properties of the gelatin gel system were studied in this paper.The results indicated that the industrial gelatin had much lower viscosity and gel strength than edible gelatin.With the increase of gelatin concentration,the viscosity and gel strength of the gelatin system increased relatively.The relaxation time for bound water(T21) and free water(T22) were reduced,and the proportion for free water(S22) decreased while that for bound water(S21) increased.As the content of industrial gelatin increased,the viscosity and gel strength of mixed gelatin system decreased linearly,and T21，T22 and S21 increased,while S22 decreased linearly.In the same sucrose or NaCl concentration,the edible gelatin system had largest viscosity and gel strength,mixed gelatin system took second place,while the industrial gelatin system had lowest viscosity and gel strength.With the increase of sucrose concentration,the viscosity of each system increased,the gel strength of edible and mixed system increased,while those of industrial gelatin changed slightly.Besides,the T21 for industrial gelatin increased,while that for edible/mixed gelatin system changed insignificantly.The T22,S22 for three systems reduced,while the S21 increased.The gel strength of each gelatin system decreased with the increase of NaCl.The T21,T22 and S21 for each system all increased,while S22 decreased.关键词：gelatin;low-field nuclear magnetic resonance(LF-NMR);sucrose;sodium chloride
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发布时间： - 摘要：A new method was developed for the determination of dimethyl sulfate and diethyl sulfate in cosmetics by gas chromatography-mass spectrometry(GC-MS).After extracted with solvent,the samples were determined by GC-MS and quantified by external standard method.The MDLs and MLOQs for the cosmetics(water-based,emulsions,creams,gel and powder),the wax cosmetics and the oiliness cosmetics were 1.5,5.0 mg/kg,3.0,10.0 mg/kg and 5.0,16.0 mg/kg,repectively.There existed a good linearity for the analyte in the concentration range of 0.25-20.0 mg/L with the correlation coefficients larger than 0.99.The recoveries of dimethyl sulfate and diethyl sulfate were in the ranges of 83.8%-104.7% and 84.7%-104.8% with their RSDs of 2.7%-8.2% and 3.5%-8.7%,respectively.The optimized method was accurate,rapid and sensitive,and was suitable for the determination of dimethyl sulfate and diethyl sulfate in cosmetics(water-based,emulsions,creams,gel,powder,wax-base and oiliness ).关键词：cosmetics;dimethyl sulfate;diethyl sulfate;gas chromatography-mass spectrometry
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发布时间： - 摘要：Two kinds of microorganisms with high detection rate in sprouts were identified by MALDI-TOF MS method as Raoultella ornithinolytica(33.3%) and Klebsiella pneumoniae(43.5%),respectively.The protein spectrums for the two microorganisms were analyzed by SARAMIS Premium,and 16 groups of characteristic peaks for R.ornithinolytica and 10 groups of characteristic peaks for K.pneumonia were identified.All peaks and weighted characteristic peaks were used for correlation analysis.The weighting for characteristic peaks could effect the correlation between different microorganisms and strengthen their resolutions.Through comparion by several methods,the two kinds of microorganisms are relatively similar in biochemical reactions.However,the 16SrDNA could isolate them,and their MS correlation trees were recognizable even though they intersected each other.The experimental results show that MALDI-TOF MS is capable of detecting the microorganisms in sprouts,and has certain advantages in their feature analysis and traceability research.MALDI-TOF MS/SARAMIS,as an open platform,could be expanded its applicable scope and improved its identified accuracy by the collection and optimization of microbial characteristics spectrums.关键词：MALDI-TOF MS;sprouts;Klebsiella pneumoniae;Raoultella ornithinolytica;identify peak;16SrDNA
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发布时间： - 摘要：Molecularly imprinted polymers were synthesized by atom transfer radical polymerization with fragment imprinting technique with the structural analogue of sulfonamide,4,6-dichloropyrimidine as template.The imprinted polymers were synthesized using 4,6-dichloropyrimidine (template),glycidyl methacrylate(functional monomer) and 2,2′- bipyridine(ligand) by the molar ratio of 10∶180∶1 at a reaction temperature of 60 ℃ and a reaction time of 5 h.The adsorption capacity for the synthetic imprinted polymers was 1.48 mg/g while that for non-imprinted polymers was 0.73 mg/g. The synthetic polymers were used as a new material for the selective separation and enrichment of veterinary drug residues in samples.The results showed that the selective adsorption capacity for the imprinted polymers was better than that for the non-imprinted polymers.The surface morphology of the polymers was characterized by scanning electron microscopy.关键词：atom transfer radicals;fragment imprinting;sulfa drugs;solid phase extraction
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发布时间： - 摘要：A high performance liquid chromatography-tandem mass spectarometry was established for the determination on migration amounts of bisphenol A,bisphenol F and bisphenol S in food contact materials.Bisphenol A,bisphenol F and bisphenol S were transfered into the food simulants in the sample contacted at a certain temperature and time.The separation was performed using a C18 chromatographic column with methanol-ammonia as mobile phase.Under the electrospray ionization(ESI)mode,bisphenol A,bisphenol F and bisphenol S were detected in a multiple-reaction monitoring mode(MRM),and quantified by the external standard method.The method indicated a perfect performance in chromatographic separation.The calibration curves of bisphenol A and bisphenol F were linear in the range of 1-50 μg/L,while the calibration curve of bisphenol S was linear in the range of 0.1-50 μg/L.The limits of detection were 0.3 μg/L for bisphenol A and bisphenol F,and 0.05 μg/L for bisphenol S.The recoveries ranged from 83.6%to 102.6%,with relative standard deviations(RSDs) of 3.5%-8.9%.This method was rapid,accurate,precise and convenient,and was appropriate for the determination of bisphenol A,bisphenol F and bisphenol S in food contact materials.关键词：food contact materials;bisphenol A;bisphenol F;bisphenol S;liquid chromatography tandem mass spectrometry
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发布时间： - 摘要：A fluorescent sensor was developed for detection of lead ion based on the replacement of double-stranded DNA and the difference of fluorescent intensity of the SG between single-stranded DNA and double-stranded DNA.As a kind of dye,SG could be inserted into the double-stranded DNA,making the SG fluorescence intensity stronger.The aptamer of lead ion reacted with its complementary strand to form a stable double chain.When lead ions existed in the solution,they could specifically bind with the aptamers to reduce the amount of double-stranded DNA.The lead ions could be quantificationally detected according to the fluorescence intensity when the SG was added into the solution.With the advantages of high sensitivity,strong specificity,simpleness and rapidness,the method has the lowest detection concentration of 2 nmol/L for lead ion,and a detection limit(S/N=3) of 1.6 nmol/L.关键词：SYBR GreenⅠ(SG);Pb2+;nucleic acid aptamer;lable-free
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发布时间： - 摘要：An analytical method was successfully developed for the rapid detection of pyrethrins in vegetables using ultra high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS).Vegetable samples were extracted with acetonitrile.After salting out,the solvent extracts were determined by UHPLC-MS/MS without further cleanup steps.The positive ion mode and multiple reaction monitoring(MRM) mode were used to identify and quantify pyrethrins in vegetables.Results showed that all six compounds had good linearity in their respective concentration ranges with the correlation coefficients of 0.999 5-0.999 9.Their average recoveries at spiked levels of 0.05,0.1, 0.5 mg/kg ranged from 73.9%to 109.3%with relative standard deviations(RSDs) of 0.4%-7.7%.The limits of quantitation(LOQs) were 0.01 mg/kg for pyrethrinⅠand pyrethrinⅡ,and 0.05 mg/kg for cinerinⅠ,cinerinⅡ,jasmolinⅠand jasmolinⅡ.Both LOQs referred to total pyrethrins.Results showed that this method was simple,rapid and sensitive,and was suitable for the rapid determination of pyrethrins in vegetables.关键词：pesticide residues;vegetable;pyrethrins;ultra high performance liquid chromatography-tandem mass spectrometry
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发布时间： - 摘要：With five kinds of facial mask as the research object,12 elements in facial masks were quantitatively analyzed by inductively coupled plasma mass spectrometry(ICP-MS) with external standard method.The relationship between mask sufficient time and elements content was established to explore the absorption rate of facial skin for trace elements.The experimental results showed that the contents rank of the elements detected in all five masks were Al,Sn,Fe,Zn and Hg,with a content range of 0.027-5.209 mg/kg.Through the absorptivity experiment,it was found that the human facial skin was more likely to absorb the elements Se,Zn and Fe other than the elements Sn and Al.In addition,the method established in this paper is simple,rapid and accurate,and could provide an experimental basis for study on trace elements in facial masks and their safe and effective uses.关键词：inductively coupled plasma mass spectrometry;facial mask;trace elements;heavy metal;quantitative analysis;absorption rate
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发布时间： - 摘要：Based on the fact that morphine has a significant inhibitory effect on Ag(Ⅲ) complex-luminol chemiluminescence system in alkaline solution and the effect is proportional to the concentration of morphine，a novel method was established for the determination of morphine by capillary electrophoresis coupled with indirect chemiluminescence detection.Under the optimized conditions,there was a linear range of 2.0-30.0 mg/L for morphine with a correlation coefficient(r) of 0.999 8 and the detection limit of 0.75 mg/L.The RSD(n=7) was 2.0%for morphine in a concentration of 20 mg/L.Combined with solid phase extraction,the method was successfully applied in the detection of morphine in urine and blood samples with the average recoveries of 109.0%and 101.3%,respectively.With the advantages of high-resolution,sensitivity and low-cost,the method could be used for the determination of morphine in urine and blood samples.关键词：chemiluminescence;capillary electrophoresis;morphine;solid phase extraction;urine sample;blood sample
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发布时间： - 摘要：With the development of chromatography and hyphenated techniques,the automated,high-throughput and rapid analysis becomes a developing trend in future.For the analysis of complex chromatographic data,the chemometric techniques based on mathematical separation have gained increasing attention.However,the previous chemometric methods cannot fully realize the automatic analysis on complex chromatographic signals.Therefore,a number of automated analysis methods are proposed.For the automated analysis of complex one-dimensional chromatographic data,two-dimensional and multi-dimensional data from the hyphenated techniques,the chemometrics methods are mainly divided into four categories: automatic chromatographic peak detection,background and baseline drift correction,chromatographic peak alignment and resolution of multicomponent overlapping signals.The principles and applications of chemometrics methods in chromatographic analysis of complex systems in recent ten years are summarized in this paper.Meanwhile,their advantages and disadvantages are also discussed.Finally,based on the existing problems,the future research focuses on automated analysis of complex chromatographic signals in this area are proposed at the end of the review.关键词：chemometrics;chromatography;complex sample;multi-dimensional data;automatic analysis
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发布时间： - 摘要：Toys or juvenile products pose potential risks to childrens health when being played,as certain elements could migrate to human bodies.The migration levels have been restricted by regulations in either China or many other countries.The exposure way and migration model of certain elements have been reviewed in this paper.The key technical parameters for three simulated migration experiments including sweat migration,saliva migration and gastric juice migration have been respectively introduced in detail and in consideration of physiological characteristics of children.Meanwhile,the differences of migration models between China and other countries have been summarized,and an outlook is made on their tendency of future development,which could provide a reference for the development of general rules for migration experiment of certain elements in toys and juvenile products.关键词：certain element;migration;test condition;technical parameter;sweat;saliva;gastric fluid;review
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