最新刊期
卷 39 ， 期 2 ， 2020
- 摘要：Chiral covalent organic frameworks(COFs) of CTpPa-1 with two dimensional eclipsed layered sheet structure was synthesized from p phenylenediamine(Pa-1) and chiral organic monomer CTp obtained by the reaction of 1,3,5-triformyloroglucinol(Tp) and (+) -diacetyl-L-tartaric anhydride.The CTpPa-1 was characterized by powder X-ray diffraction(PXRD),Fourier transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM) and nitrogen adsorption.The CTpPa-1 were mixed with C18 to use as a stationary phase for fabricating a packed chiral high performance liquid chromatography(HPLC) column.The resolution ability of the chiral column for different chiral compounds were investigated under different ratios of n hexane-isopropanol as mobile phase.Results showed that the chiral column exhibited a good resolving ability towards 18 racemates,including alcohols,ketones,phenols,organic acids and amines,among which five chiral compounds reached the baseline separation,and seven chiral compounds were close to the baseline separation.The highest resolution(RS) was 3.65.Some positional isomers including nitrophenol,bromoaniline and dinitrobenzene could be separated on the chiral column.Finally,the reproducibility and stability of the chiral column were evaluated.The relative standard deviations(RSD) for retention time and peak area after 50,100,150,200,250 injections of 1-(4-chlorophenyl) ethanol were 0.86% and 1.1%，respectively,indicating that the chiral column had good reproducibility and stability.关键词：covalent organic framework;high performance liquid chromatography;stationary phase;chiral separation
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发布时间：2023-05-25 - 摘要：An ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) with Captiva EMR-Lipid pretreatment screening technique was established for the simultaneous analysis of 51 drug residues in pork,chicken and eggs.2.0 g of each sample was extracted with Mcllvaine-Na2EDTA buffer and acidified acetonitrile,then purified with Captiva EMR-Lipid,and finally detected by UPLC-MS/MS with electrospray ionization in positive ion scanning under multiple reaction monitoring mode.Some compounds were quantified by internal standard method,and the others were quantified by external standard method.Results showed that there were good linear relationships for 51 drugs in the range of 0.5-10 μg/L with correlation coefficients(r) not less than 0999 0.The limits of detection and quantitation were 2.5 μg/kg and 5.0 μg/kg,respectively.Average recoveries for all compounds in pork,chicken and egg samples at spiked levels of 5,10,20 μg/kg were between 60% and 110%,with relative standard deviations(n=5) lower than 10%.With simple operation and high accuracy,the method was suitable for screening of multiple drug residues in pork,chicken and eggs.关键词：Captiva EMR-Lipid;ultra performance liquid chromatography-tandem mass spectrometry;animal products;drug residues
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发布时间：2023-05-25 - 摘要：In this study,a molecularly imprinted electrochemical sensor for tetracycline（TC）,MIPs/GQDs-AuNPs/GCE was constructed,with TC as template molecule and 4-aminothiophenol（4-ATP） as functional monomer,by electrically polymerizing them both on the surface of glassy carbon electrode modified with gold nanoparticles and graphene quantum dot composites through cyclic voltammetry（CV）.CV,electrochemical impedance spectroscopy（EIS） and linear scan voltammetry（LSV） were used to investigate the electrochemical response of the molecularly imprinted sensor.Results showed that the sensor possessed a good current response to tetracycline.Under the best experimental conditions,there was a good linear relationship for the oxidation peak current of TC in the concentration range of 2.0×10-8-3.0×10-5 mol/L,with a correlation coefficient of 0.999 4.The detection limit was 1.5×10-9 mol/L.The recoveries were in the range of 97.9%-106%.With good stability,high sensitivity and selectivity,the sensor has a good prospect for application.关键词：gold nanoparticles;graphene quantum dots;tetracycline;molecularly imprinted membrane;electrochemical sensors
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发布时间：2023-05-25 - 摘要：A method for preparation and determination of naringenin certified reference material was established.Qualitative analysis of purchased samples was performed using infrared spectroscopy and nuclear magnetic resonance.The samples were purified by column chromatography and dried at 105 ℃ for 6 h,after mixing and dispensing,120 bottles of reference material candidates were obtained.Purity determination was carried out by differential scanning calorimetry and mass balance method.The mass balance method based on area normalization method of liquid chromatography,included detections on contents of moisture,inorganic impurities and residual solvents.Homogeneity and stability studies were validated by liquid chromatography,and uncertainty of the determination results was also analyzed.Results showed that the developed naringenin certified reference material had good homogeneity and stability,with a purity of 99.2%,an expanded uncertainty of 0.2%(k=2) and a validity period of 6 months.关键词：naringenin;qualitative analysis;certified reference materials;uncertainty
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发布时间：2023-05-25 - 摘要：A reliable and efficient method for the determination of N-glycan structures in glycoprotein was developed by the combination of two dimensional offline liquid chromatography and exoglycosidase sequencing.Firstly, the N-glycans at different sialylation degrees were prepared by weak anion exchange chromatography,then the structures of analytes were identified by capillary electrophoresis-laser induced fluorescence detection(CE-LIF) combined with exoglycosidase digestion.After fluorescent labellling,the structural annotation was performed by the top-down digestion and the bottom-up identification,and a total of 18 N-glycan structures in Immunoglobulin G(IgG) were identified.Finally,the same method was applid in the analysis of N-glycans in human serum samples.The ratio for monosialylated,disialylated,trisialylated and tetrasialylated degree was 4.7∶20.9∶6∶1Results showed that high abundance neutral sugar chains in human serum were very similar to those in IgG in structure,and the disialylated N-glycan structure FA2G2S2 was the most abaundent in serum N-glycan pool.The method had an application potential in N-glycosylation analysis.关键词：offline two-dimensional chromatography;capillary electrophoresis;immunoglobulin G(IgG);N-glycan;human serum
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发布时间：2023-05-25 - 摘要：A solid phase micro extraction(SPME)/gas chromatography-mass spectrometry(GC-MS) was established for the detection of volatile compounds in edible bird's nest(EBN) derived from Indonesia.The samples were extracted by SPME and identified by GC-MS.Effects of type of SPME column,extraction time,extraction temperature and desorbing time on extraction efficiencies for volatile compounds in EBN were investigated.Results indicated that 82 kinds of alcohols,hydrocarbons,aldehydes,esters,ethers,and etc.in EBN were detected with a 65 μm polydimethylsiloxane/divinylbenzene(PDMS/DVB) fused silica fiber at 60 ℃ for extraction time of 60 min and desorbing time of 2 min.With the characteristics of easy operation,rapidness,high repeatability and high sensitivity,the method is suitable for determination of the volatile compounds in EBN.关键词：edible bird's nest(EBN);volatile compounds;solid phase micro extraction(SPME);gas chromatography-mass spectroscopy(GC-MS)
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发布时间：2023-05-25 - 摘要：An QuEChERS/gas chromatography triple quadrupole mass spectrometry(GC-MS/MS) was developed for the simultaneous determination of 28 organophosphorus pesticide residues in Amomum villosum.The sample was firstly extracted with acetonitrile containing 1% acetic acid(by volume),and then purified with a mixed sorbent of 900 mg MgSO4,150 mg PSA,100 mg C18 and 25 mg GCB.After being concentrated and filtered,the extract was analyzed by GC-MS/MS in multiple reactions monitoring(MRM) mode and quantified by the matrix matched standard calibration curve method.Results showed that the calibration curves for 28 organophosphorus pesticides detected were linear in the range of 0.05-1.00 mg/L with correlation coefficients(r2) more than 0.99.The average recoveries at spiked levels of 0.2,0.4,1.0 mg/kg for all target compounds in the samples were in the range of 821%-104%,with relative standard deviations(RSD) no more than 15%.The limits of detection(LODs) ranged from 0.005 mg/kg to 0.010 mg/kg,and the limits of quantitation(LQDs) were between 0.010 mg/kg and 0.033 mg/kg.With simplicity,rapidness,good sensitivity,accuracy and precision,the method could provide a fast,efficient and reliable analytical approach for improving the quality and safety of Amomum villosum.关键词：Amomum villosum;pesticide residues;gas chromatography-triple quadrupole mass spectrometry(GC-MS/MS);QuEChERS
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发布时间：2023-05-25 - 摘要：A total of 92 samples from three countries,ie.the United States,Canada and PR.China were determined by inductively coupled plasma mass spectrometry(ICP-MS) and inductively coupled plasma(ICP)-optical emission spectroscopy(OES).A regional discrimination model was set up using the mineral element content combined with chemometrics of Principal component analysis(PCA) and Partial least squares discriminant analysis(PLS-DA).Results showed that the PCA and PLS-DA multivariate statistical models could be used to distinguish the cherry samples from these three countries.Cherries from the United States,Canada and China appeared a certain clustering effect,but Canadian cherries exhibited a certain intersection with American cherries.The PLS-DA origin traceability model for cherry samples showed that 20 elements such as Pr,Nd,Ce,Y,Co,Mo,Mn,Dy,Gd,Ni,Ho,Sm,Sr,Er,Ga,U,Na,Yb,Be and Zn were the main significant elemental variables.According to the distribution of these 20 elements,the traceability identification model for cherries could be constructed.The identification rates of the PLS-DA origin traceability model for the three source cherry samples was 50% from the US,83.3% from Canada and 83.3% from China.关键词：cherry;element analysis;origin traceability;Principal component analysis(PCA);Partial least squares discriminant analysis(PLS-DA)
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发布时间：2023-05-25 - 摘要：A fluorescent method based on copper/silver nanoclusters for the detection of Cu2+ was established by designing DNA sequences with G rich bases and investigating the fluorescence enhancement effect of G base pairs on DNA-Cu/AgNCs.It was found that the fluorescence intensity of the prepared DNA-Cu/AgNCs was significantly enhanced by the G5 sequence at the 5′ end of the C rich sequence template.Meanwhile,the fluorescence of DNA-Cu/AgNCs was quenched by Hg2+ and Cu2+.NaBH4 could be used to mask Hg2+ in order to achieve a selective detection of Cu2+.The linear range of this method for Cu2+ was from 0.01 μmol/L to 5.0 μmol/L,and the detection limit was 5.0 nmol/L.The method is simple,rapid,highly selective and low cost,and is able to apply in detection for real samples.关键词：fluorescent sensing;metal nanoclusters;fluorescence enhancement;copper ion;DNA
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发布时间：2023-05-25 - 摘要：Based on the fact that hydrogen cyanide reacts with ninhydrin hydrate in alkaline condition,and resulting to the solution turning purple red,a rapid and sensitive method was developed for on site detection of hydrogen cyanide in water sources.The factors such as type of chromogenic agent,concentration of ninhydrin hydrate,pH value,reaction temperature and time were optimized.The RGB colorimetric method originated from the normalized RGB system were used in the detection,overcoming the problem that three stimulus values changed with the variation of light intensity based on the RGB model.Under the optimum conditions,there were good linear relationships between chromaticity values and hydrogen cyanide concentrations in the range of 0.04-3.96 mg/L.The theoretical detection limit for R value was 0.038 mg/L and the actual detection limit was 0.04 mg/L.The method was successfully applied in the determination of hydrogen cyanide in artificial water samples with recoveries of 98.3%-111%.With high selectivity,sensitivity and reproducibility,the method also had an application potential in the analysis of other toxic and harmful substances in environment.关键词：portable;RGB chromaticity sensor;quantitative determination;hydrogen cyanide;water
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发布时间：2023-05-25 - 摘要：High field asymmetric waveform ion mobility spectrometry(FAIMS) is a chip level rapid analysis technique with high sensitivity.Its characteristics under atmospheric pressure make it easily affected by the environment,of which the humidity of the gas is a significant factor.The variation of humidity caused change of the reaction mechanism of ions in the migration zone and change of the migration process.A method based on FAIMS was developed for the quantitative detection of trace hydrogen sulfide under dry conditions,and the linear range and regression equation of the detection at DF=33% were determined.Effects of different moisture contents on the detection of hydrogen sulfide by FAIMS were investigated by using the PTFE tube penetration effect and setting the water bath temperature at 40-90 ℃,while the effects of doped moisture on the peak value,compensation voltage,and resolution were studied by examining the FAIMS characteristic spectra and ionic peaks of hydrogen sulfide under different humidity.Results showed that FAIMS was clearly visible for the detection of hydrogen sulfide,and could accurately locate its characteristic ion peak.With the increase of moisture in the gas,the peak values of the product ions under different separation electric fields increased,indicating that the increase in humidity improved the sensitivity,to a certain extent.The detection limit at DF=35% was 1.43×10-3 mg/m3.关键词：high field asymmetric waveform ion mobility spectrometry(FAIMS);waterdoping;detection limit;resolution
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发布时间：2023-05-25 - 摘要：A two dimensional thin layer chromatography-surface enhanced Raman scattering(TLC-SERS) method was constructed with highly stable and sensitive nanogold/porous silica composites as SERS substrate.This technique improved the separation capability by combining the rapid separation function of TLC and the qualitative and quantitative analysis function of SERS.The homogeneity and batch reproducibility of the substrate were studied using a p-aminothiophenol as probe.Mapping experiment showed that the substrate had a good point-point repeatability,with a relative standard deviation(RSD) of 5.9% for the peak intensities at 24 measuring points.Moreover,the RSD for 9 batches of substrates was 75%.The linear range of the substrate for the detection of saccharin sodium was 0.1-200 mg/L with the detection limit of 0.06 mg/L.The substrate was applied in the detection of saccharin sodium in actual samples,with the target concentrations in beverage and fruit of 141 mg/L and 18 mg/L,respectively.The whole analytical process could be completed within 10 min.With the advantages of high sensitivity,strong specificity and simple pretreatment,the method could realize the rapid determination of saccharin sodium in drinks and fruits.关键词：two dimensional thin layer chromatography;surface enhanced Raman scattering;saccharin sodium;beverage;fruit
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发布时间：2023-05-25 - 摘要：A fluorescence probe,2-Hp-β-CDCdTe QDs for the detection of crystal violet(CV) was fabricated in the presence of TGA as stabilizer and 2-hydroxypropyl-β-cyclodextrin(2-Hp-β-CD) as modifier,which showed high fluorescence intensity,water solubility and light stability,as well as good inclusion ability for CV.The interaction between 2-Hp-β-CDCdTe QDs and CV was investigated by UV-Vis,fluorescence spectroscopy and TEM.The data indicated that the distance between the donor and the acceptor was reduced significantly by the action of CTAB,and the energy transfer between the QDs and CV was promoted.The fluorescence spectrum for QDs could overlap the absorption spectrum of CV effectively.Based on this,the fluorescence resonance energy transfer(FRET) system between QDs and CV was established,which could be used for the determination of CV.Results showed that in pH 8.0 Tris-HCl buffer,CV could quench the fluorescence peak of 2-Hp-β-CDCdTe QDs in the presence of CTAB,and there was a good linear relationship between the change of fluorescence intensity(ΔF) and CV concentration in the range of 1.0×10-7-1.0×10-5 mol/L(r2=0995 2).The detection limit was 1.74×10-8 mol/L,and the average recoveries were in the range of 99.0%-106%.关键词：2-hydroxypropyl-β-cyclodextrin(2-Hp-β-CD);CdTe quantum dots;crystal violet(CV);fluorescence analysis;fluorescence resonance energy transfer(FRET)
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发布时间：2023-05-25 - 摘要：A capillary electrophoresis(CE) method was established for the simultaneous separation and determination of seven preservatives in cosmetics,including methyl p hydroxybenzoate,ethyl p-hydroxybenzoate,propyl p hydroxybenzoate,butyl p hydroxybenzoate,chlorophenylglycol,octanoyl valerate and sodium dehydroacetate.Effects of different electrophoresis conditions,including type and concentration of additive,pH value of the running buffer and separation voltage on separation were investigated.The optimal conditions were follows:additive:10 mmol/L sulfobutyl-β-cyclodextrin,buffer:pH 8.0 20 mmol/L phosphate buffer,separate voltage:20 kV,detection wavelength:280 nm.Results showed that,under the optimal conditions,seven preservatives could reach the baseline separation within 5 min.The calibration curves were linear in the concentration range of 5-200 mg/L,with correlation coefficients(r) of 0.990 7-0998 9.The detection limits were in the range of 123-430 mg/L,and the relative standard deviations(RSD) for migration time were not more than 1.3%.Average recoveries for the spiked samples were in the range of 95.4%-103%.The method is accurate,simple,efficient and practical,and could be applied in the determination of seven preservatives in actual samples.关键词：capillary electrophoresis;cosmetics;preservatives;separation and determination
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发布时间：2023-05-25 - 摘要：A contactless conductivity method with microfluidic chip was established for the rapid determination of memantine hydrochloride in memantine hydrochloride tablet.Effects of electrophoresis parameters such as variety,concentration,pH value of buffer solution,injection time and separation voltage on the separation detection were investigated.The optimized buffer system was 3.0 mmol/L triethylamine-2.0 mmol/L phosphate buffer solution(pH 3.3) containing 2%(by volume) dimethyl sulfoxide(DMSO),the injection time was 10 s and the separation voltage was 2.0 kV.In the optimal conditions,the linear range for memantine hydrochloride was 10-2 000 μg/mL(r2=0.999 1).The limits of detection and quantitation were 7 μg/mL and 10 μg/mL,respectively.Relative standard deviations for precision,stability and reproducibility tests were lower than 2.0%,and average recoveries for memantine hydrochloride were in the range of 96.5%-99.2%,with a detection time less than 18 s.The method is rapid and simple,and is suitable for the determination of memantine hydrochloride in memantine hydrochloride tablet.关键词：microfluidic chip;contactless conductivity detection;memantine hydrochloride;memantine hydrochloride tablet
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发布时间：2023-05-25 - 摘要：A method for the determination of six isophthalate esters in plastic toys,including dimethyl isophthalate,diethyl isophthalate,diallyl isophthalate,bis(2-ethylhexyl) isophthalate,diphenyl isophthalate and di-n-octyl isophthalate was established by gas chromatography-mass spectrometry(GC-MS) with solid phase extraction(SPE).The samples were ultrasonically extracted with ethyl acetate,precipitated with methanol and purified with an HLB solid phase extraction column,then the analytes were separated on an HP-5MS column(30 m×250 μm×0.25 μm),detected in selected ion monitoring mode and quantified by external standard method.Results showed that the standard curves for six isophthalate esters were linear over the concentration range of 0.1-5.0 mg/L,with correlation coefficients(r2) greater than 0.995.The detection limits of the method(S/N=3) were in the range of 0.22-0.60 mg/kg,and the spiked recoveries were between 87.3% and 116% with relative standard deviations of 1.5%-9.5%.The method is simple,rapid and sensitive,and is suitable for the determination of isophthalate esters in plastic toys.关键词：solid phase extraction(SPE);gas chromatography-mass spectrometry(GC-MS);plastic toys;isophthalate esters
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发布时间：2023-05-25 - 摘要：A high performance liquid chromatography-inductively coupled plasma mass spectrometry(HPLC-ICP/MS) was developed for the determination of five speciations of selenium,i.e.selenocystine(SeCys2),methylselenocysteine(MeSeCys),selenite［Se(Ⅳ)］,selenomethionine(SeMet) and selenate［Se(Ⅵ)］ in human urine.The samples were diluted with ultra pure water,and separated on a Hamilton PRP-X100 column(250 mm×4 mm，10 μm) by isocratic elution using 40 mmol/L diammonium hydrogen phosphate containing 1% methanol(pH 5) as mobile phase.Five selenium speciations could be separated within 13 min.There were linear relationships for five selenium speciations in the range of 0-300.0 μg/L with correlation coefficients(r) larger than 0.999.The detection limits of the method were 0.2-0.5 μg/L.Recoveries for MeSeCys,Se(Ⅳ),SeMet and Se(Ⅵ) were in the range of 80.0%-123%,except that the recovery for SeCys2 was 37.7%-70.4%.The relative standard deviations(RSD) were not more than 7.8%.Results showed that SeCys2 was the main selenium speciation in human urine,and a small amount of MeSeCys,SeMet,inorganic selenium and some unknown selenium compounds were also found.关键词：human urine;selenium speciation;high performance liquid chromatography-inductively coupled plasma mass spectrometry
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发布时间：2023-05-25 - 摘要：In this paper,a gas chromatography-triple quadrupole mass spectrometric(GC-MS/MS) method was developed for the rapid detection of four furfural compounds,i.e.5-hydroxymethyl-2-furfural(5-HMF),furfural(F),5-methyl-2-furfural(MF) and 2-acetylfuran(FMC) in fermented milk,which originated from heat treatment.The samples were pretreated by QuEChERS method,then separated on a RTX-WAX column,and finally detected in multi reaction monitoring(MRM) mode.Moreover,the three pretreatment conditions for this experiment were optimized,including extraction solvent,amount of salting-out agent and amount of purifying agent.Under the optimum conditions,the spiked recoveries ranged from 82.2% to 118% with relative standard deviations(RSDs) no more than 10%.There were good linearities for F,FMC and MF in range of 0.002-2 mg/L,and for 5-HMF in the range of 0.02-2 mg/L,with their correlation coefficients not less than 0998.The limits of quantitation(LOQs) and detection limit(LODs) of the method were 3.0-45 μg/kg and 1.0-15 μg/kg,respectively.This method was applied in the determination of five kinds of original favor fermented milk and six kinds of charcoal flavor fermented milk.Results showed that the contents of four furfural compounds in charcoal flavor fermented milk were much higher than those in original fermented milk,indicating that charcoal burning process could lead to the Maillard reaction proceeding thoroughly,indirectly showing that overheat treatment could result in more harmful compounds in fermented milk,which affected its nutritional value and quality.The method is simple,rapid,sensitive and reproducible,and could meet the requirements for qualitative and quantitative analysis,and provide consumers with reasonable purchase suggestions and guidance.关键词：gas chromatography couple with triple quadrupole mass spectrometry(GC-MS/MS);furfural compounds;QuEChERS;fermented milk
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发布时间：2023-05-25 - 摘要：A method was developed for the determination of quinoline and isoquinoline in textiles by gas chromatography-mass spectrometry(GC-MS).The experimental conditions for extraction were optimized.The textile samples were ultrasonically extracted with ethyl acetate as organic solvent.After being concentrated by evaporation and set to a certain volume,the extracts were determined by GC-MS.Under the optimal conditions,the calibration curves for quinoline and isoquinoline were linear(r>0.999 0) in the concentration range of 0.05-10.0 mg/L.Recoveries were in the range of 82.0%-99.8% with their relative standard deviations(RSD,n=6) of 0.9%-3.8%.The limits of quantitation were 0.05 mg/kg.The method was sensitive,simple,efficient and accurate,and could meet the requirements for detection of quinoline and isoquinoline in textile products.关键词：textiles;quinoline;isoquinoline;ethyl acetate;gas chromatography-mass spectrometry(GC-MS)
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发布时间：2023-05-25 - 摘要：The authenticity identification and origin traceability for aquatic products have always been the hot issues in the field of food safety.In recent years,modern analytical techniques such as spectroscopy,nuclear magnetic resonance(NMR),enzyme linked immunosorbent assay(ELISA),nucleic acid testing,electrophoresis,chromatography and mass spectrometry(MS) are powerful tools for the analysis on species,origins and contents of aquatic products.The classification,principle,research platform and latest applications of the authenticity identification and traceability detection methods for aquatic products are introduced in this paper.Finally,the trends and promising prospects of this field are presented.关键词：aquatic products;authenticity identification;origin traceability;analytical methods
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发布时间：2023-05-25
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