最新刊期
卷 38 ， 期 4 ， 2019
- 摘要：An electrochemical method of scanning electrochemical microscopy（SECM）was developed for the detection of extracellular reactive oxygen species（ROS）based on H2O2.The release of ROS was investigated by SECM technique after stimulation of lung cancer cells（A549）with tetradecanoylphorbol acetate（PMA）.The distance between the electrode and petri dish was determined as about 8 μm,and the cell morphology was shown clearly with hexamineammonium chloride（Ru（NH3）6Cl3）as the solution mediator in negative feedback mode.The release of ROS from A549 cells treated with PMA in real time were evaluated using SECM imaging when the potential of the probe was set at -0.65 V.Expanding the imaging range,SECM images of the release of ROS from different cells and the real time capture of ROS signals were obtained.Overall,the PMA induced ROS production was successfully determined.Moreover,at the corresponding ROS release site,the current variation with time was fluctuating.It was speculated that the release of ROS from cells was a dynamic pulsation process in this condition.关键词：scanning electrochemical microscopy（SECM）;reactive oxygen species;H2O2;cell
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发布时间： - 摘要：An analytical method was established for the confirmation and quantitation of short chain carboxylic acids in aged transformer oil by gas chromatography-tandem mass spectrometry（GC-MS）and high performance liquid chromatography with dispersive liquid-liquid microextraction（DLLME/HPLC）.The short-chain carboxylic acids in aged transformer oil were detected by GC-MS using N,O-bis-（trimethylsilyl）-trifluoroacetamide（BSTFA）as silane derivatization reagent,and formic acid,acetic acid and furoic acid in transformer oil were quantified by DLLME/HPLC.After extracting carboxylic acid in transformer oil with acetonitrile as extractant,BSTFA was added into the extraction phase of acetonitrile for silylation derivatization.After 60 min of the reaction at 60 ℃,the samples were determined by GC-MS.Results showed that 14 kinds of short chain carboxylic acids were detected in heat aged transformer oil,including formic acid,acetic acid and furoic acid.The formic acid,acetic acid and furoic acid in the standard oil sample were extracted with water as extractant which was directly taken for injection.The calibration curves of formic acid,acetic acid and furoic acid in the transformer oil were linear in the ranges of 0.05-50.0 mg/L,0.05-50.0 mg/L and 0.01-2.0 mg/L,respectively,with correlation coefficients（r） more than 0.998.The limits of detection（LOD） of the method were 36.1，47.3 and 7.0 μg/L,with relative standard deviations（RSD） of 2.4%,3.3% and 3.6%,respectively.The enrichment factors for the three carboxylic acids were within the range of 8-10 times.The recoveries for the aged oil samples ranged from 91.7%to 107%.The proposed method is simple and effective,and provides analytical data for the correct use of aged characteristic quantity of transformer oil paper insulation and study on effect of carboxylic acid on aged oil paper insulation.关键词：silylation derivatization;gas chromatography-tandem mass spectrometry（GC-MS）;short-chain carboxylic acid;dispersive liquid-liquid microextraction（DLLME）;high performance liquid chromatography（HPLC）;transformer oil
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发布时间： - 摘要：A multispectral features fusion technique(MFFT) was developed for the quantitative analysis of adulterated components in flour samples in this paper.The MFFT consisted of iterative wavelet transform(AWT),competitive adaptive reweighted sampling(CARS) and partial least squares regression(PLS),utilizing the molecular information in Raman spectroscopy and the atomic information in laser induced breakdown spectroscopy(LIBS) to extract important features efficiently.In the MFFT,AWT and CARS were combined to select features in the Raman spectra and LIBS spectra,respectively,which were fused for PLS modeling.As a result,the MFFT model was generated to quantitate the adulterant contents in flour samples.To verify the performance of the MFFT method,the titanium dioxide and aluminum potassium sulfate in flour samples were quantitated.When compared with the prediction models based on individual spectroscopy,the correction coefficients of the MFFT models for titanium dioxide and aluminum potassium sulfate were significantly improved from 0.884,0.877 of Raman models to 0.981,0.980,whose root mean square errors were also decreased from 0.151,0.154 of Raman models to 0.069,0.068,respectively.Results indicated that the MFFT is a promising tool for quantitative analysis of adulterants in flour samples,extracting the molecular information in Raman spectra and the element information in LIBS spectrua accurately.The MFFT could make Raman spectroscopy and LIBS spectroscopy complementary for mutual correction,suppressing the effects of flour matrix on the quantitative analysis of adulterated components effectively,improving the prediction accuracy of the model significantly.关键词：Raman spectroscopy;laser induced breakdown spectroscopy;multispectral feature fusion technology;flour adulteration
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发布时间： - 摘要：A method was developed for the determination of 4 aflatoxins and 11 pesticide residues in peanut by ultrahigh performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry（UPLC-HRMS）.The samples were extracted with acetonitrile-water-acetic acid（84∶15∶1，by volume）,and the extracts were cleaned up with 1.0 g MgSO4,100 mg PSA and 400 mg C18.The analytes were separated on a Hypersil Gold C18 column（100 mm×2.1 mm，1.9 μm）,and quantified by UPLC-HRMS.Results showed that 4 aflatoxins and 11 pesticide residues had good linear relationships in their respective mass concentration ranges with their correlation coefficients（r2）more than 0.996.The limits of quantitation（LOQs）of the method ranged from 0.25 μg/kg to 1.0 μg/kg.The spiked recoveries for 4 aflatoxins and 11 pesticide residues at three spiked levels ranged from 79.4%to 120%with relative standard deviations（RSD,n=6） of 4.2%-10%.With the advantages of high sensitivity and reliability,the method was suitable for the simultaneous determination of 4 aflatoxins and 11 pesticide residues in peanut.关键词：high resolution mass spectrometry（HRMS）;peanut;aflatoxins;pesticide residues
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发布时间： - 摘要：A differential pulse voltammetric（DPV） method was developed for the detection of phoxim based on solid liquid microextraction on nanoparticle cobalt hydroxide in situ modified carbon paste electrode.Phoxim was detected by with nanoparticle cobalt hydroxide in-situ modified carbon paste electrode.Under the applied potential,phoxim molecules were extracted onto the electrode surface,which interacted with cobalt hydroxide to form a complex and result in an irreversible reduction peak at-0489 V.The reduction peak current increased linearly with the increase of scan rate,indicating that the reduction reaction was controlled by surface adsorption.The extraction behavior followed a Temkin isothermal adsorption model.The relationship between pH and potential showed that the reduction process was just a reaction of an electron with a proton.Electrochemical impedance spectroscopy（EIS） and quantum chemical method were used to prove that the reduction reactions could occur spontaneously,while the calculation results were consistent with the experimental results.The system was used to detect phoxim.There existed linear relationships between the reduction peak current and logarithm of phoxim concentration in the ranges of 3.333×10-13-3.333×10-8 mol/L and 3.333×10-8-3.333×10-6 mol/L.The limits of detection（S/N=3） was 3.333×10-13 mol/L.With good reproducibility and selectivity,the method was applied in the determination of phoxim pesticides in spinach with satisfactory results.关键词：nanoparticle cobalt hydroxide;carbon paste electrode;phoxim
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发布时间： - 摘要：A rapid method of ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）was developed for the simultaneous determination of 12 carbamate pesticide residues in camellia oil based on solid phase extraction with multi walled carbon nanotubes（MWCNTs）as adsorbent.The samples were ultrasonically extracted with acetonitrile,then cleaned up with a MWCNTs SPE column.After elution with acetonitrile and concentration,the extracts were adjusted to the volume with a mixture of 01%acetic acid-acetonitrile（5∶5,by volume）.The target compounds were determined by UPLC-MS/MS in multiple reaction monitoring（MRM）mode,and quantified by external standard method.Effects of extraction methods,types of sorbents and dosages of elution solvents on the extraction efficiency were investigated.Under the optimal conditions,the MWCNTs solid phase extraction cartridge has an ideal purification effect on 12 carbamate pesticides in camellia oil,which could effectively eliminate the matrix effect.There were good linear relationships for 12 carbamate pesticides in the range of 0.005-0.1 μg/mL with their correlation coefficients（r） not less than 0.998 88.Average recoveries for 12 targets at spiked levels of 0.01,0.025 and 0.05 mg/kg ranged from 78.3%to 116%with relative standard deviations of 2.6%-12%.The limits of quantitation（LOQ）of the method were in the range of 0.2-3.0 μg/kg.关键词：camellia oil;carbamate pesticide residues;multi walled carbon nanotubes;solid phase extraction;ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）
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发布时间： - 摘要：A gas chromatography triple quadrupole mass spectrometry(GC-MS/MS) with accelerated solvent extraction was developed for the determination of 20 organophosphorus pesticides residues in Chinese wolfberry.The samples were first extracted with acidified acetonitrile-dichloromethane(4∶1,by volume),then purified on a Cleanert TPH solid phase extraction column,next concentrated by rotary evaporation and dried with nitrogen,and finally analyzed by GC-MS/MS.The experimental conditions such as extraction solvent,temperature and rinse volume were optimized.Results showed that the calibration curves for 20 pesticides were linear in the range of 1-500 μg/kg with their correlation coefficients(r2) of 0.999 0-0.999 8.The spiked recoveries at three levels of 20,40 and 100 μg/kg were in the range of 70.0%-82.9% with the relative standard deviations(RSDs,n=5) of 0.6%-8.5%.The limits of quantitation of the method ranged from 1.0 μg/kg to 15.0 μg/kg.The method is simple and accurate,and is suitable for the determination of organophosphorus pesticide residues in Chinese wolfberry.关键词：accelerated solvent extraction;organophosphorus pesticides;solid phase extraction(SPE);gas chromatography-triple quadrupole mass spectrometry(GC-MS/MS)
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发布时间： - 摘要：A new method of magnetic metal organic framework（Fe3O4@MOFs） surface assisted laser desorption ionization mass spectrometry（SALDI-MS） was established,based on the ambient synthesization of core-shell magnetic zeolitic imidazolate framework-8（Fe3O4@ZIF-8） microspheres by a simple self assembly method with carboxylated Fe3O4 as the core.The effects of different sample preparation methods such as dried droplet method,thin layer method and sandwich method were investigated in details.Results showed that the sample prepared by sandwich method has many advantages including uniform matrix distribution,little “sweet point”,high sensitivity,and good signal reproducibility.In this paper,triglycerides in peanut oil,lard and canola oil were used as target objects,and different edible oils were identified by the SALDI-MS method rapidly.Compared with traditional MALDI-MS method,the SALDI-MS method based on Fe3O4@ZIF-8 could obtain more abundant composition information of oil,better mass resolution and higher detection sensitivity,could be better applied in the rapid identification of edible oil samples.关键词：magnetic metal organic frameworks;surface assisted laser desorption ionization mass spectrometry;rapid identification;edible oils
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发布时间： - 摘要：A high performance liquid chromatography-quadrupole-time of flight mass spectrometric（HPLC-Q-TOF/MS）method with a modified QuEChERS purification was developed for the rapid screening of unkown illegal additive residues in herbal teas.The target compounds in samples were extracted with 0.5%acetic acid-acetonitrile,cleaned with NH2 sorbent and separated on a C18 column（100 mm×2.1 mm，1.7 μm）,then determined by HPLC-Q-TOF/MS.The detection limits and the quantitation limits for 8 control drugs were in the ranges of 2.0-10 μg/kg and 5.0-25 μg/kg,respectively.The average recoveries for the samples at three spiked levels ranged from 75.8%to 95.6%,with RSD（n=6）of 2.1%-6.5%.Moreover,the acquired data were compared with the library using the accurate mass,isotopic distribution,fragmentation information to screen illegal additive residues in herbal teas without reference standards.The developed method was used in the determination of 50 herbal tea samples.Results showed that paracetamol was detected in 10 samples,with content range of 4.14-2 188 mg/kg.This method is efficient,sensititive and accurate,and could meet the requirement for rapid screening of unkown illegal additive residues in herbal teas.关键词：QuEChERS;high performance liquid chromatography-quadrupole-time of flight mass spectrometry（HPLC-Q-TOF/MS）;non target screening;herbal tea;illegal additive residues
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发布时间： -
Simultaneous Determination of Dopamine,Ascorbic Acid and Uric Acid Using Poly（ViEtIm+Br-）/MWCNTs/GCE
摘要：In the present work,functionalized ionic liquid of 1-vinyl-3-ethylimidazolium bromide (ViEtIm+Br-) was firstly synthesized by reaction of 1-vinylimidazole and 1-bromoethane.Poly(1-vinyl-3-ethylimidazolium bromide) polymeric ionic liquid (Poly(ViEtIm+Br-)) was obtained through polymerization reaction of (ViEtIm+Br-) by using azobis (2-methylpropionitrile) as initiator.Then,the composite of polymeric ionic liquid modified multi walled carbon nanotube (Poly(ViEtIm+Br-)/MWCNTs) was prepared under mild conditions through a non conjugated method by taking advantage of strong π-π interaction between MWCNTs and imidazole group,which was designed as an efficient electrode modifider for the simultaneous determination of UA,DA and UA.The experimental results showed that the Poly(ViEtIm+Br-)/MWCNTs/GCE displayed a linear response for DA,AA and UA in the range of 2-180 μmol/L,50-5 000 μmol/L and 4-50 μmol/L,respectively,and the detection limits were 0.4，22.2,0.9 μmol/L,respectively.The Poly(ViEtIm+Br-)/MWCNTs/GCE was successfully used for the detection AA in vitamin C injection and DA in dopamine hydrochloride injection with recoveries of 98.8%-101%.关键词：polymeric ionic liquid（PIL）;ascorbic acid;uric acid;dopamine;multi walled carbon nanotubes- 733
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发布时间： - 摘要：A rapid method was developed for the determination of penicillin G and its two metabolites（penillic acid and penilloic acid） residues in citrus by dispersive solid phase extraction/ultra high performance liquid chromatography-tandem mass spectrometry（DSPE/UPLC-MS/MS）.The citrus samples were extracted with 80% acetonitrile,then purified with C18.The analytes were separated on an Acquity UPLCHSS T3 column with acetonitrile and 01% formic acid solution as mobile phases by gradient elution,and finally detected by tandem mass spectrometry in positive ESI mode（ESI+）.Identification and quantitation were performed by UPLC-MS/MS under multi reaction monitoring（MRM） mode and matrix matched standard curve method,respectively.Results showed that three analytes could realize an effective and rapid separation within 5 min.There were good linear relationships for the analytes in the concentration range of 5-2 000 μg/L with their correlation coefficients（r2） not less than 0.998 1.The limits of detection（LOD） and limits of quantitation（LOQ） of the method were in the ranges of 0.5-1 μg/kg and 5-10 μg/kg,respectively.The spiked recoveries for penicillin G and its metabolites in blank citrus samples were in the range of 76.7%-107%,with relative standard deviations（RSD） of 1.3%-9.6%.The method is rapid,simple,sensitive and accurate,and is suitable for the determination of penicillin G and its two metabolite residues in citrus.关键词：dispersive solid phase extraction;penicillin G;metabolites;ultra high performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）;citrus
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发布时间： - 摘要：A high performance liquid chromatography-quadrupole ion trap mass spectrometric（HPLC-QTRAP-MS/MS）method was developed for the determination of two potential genotoxic impurities residues,ieomeprazole N-oxide（GTI E）and sulfonylate N-oxide（GTI I）in esomeprazole sodium.The esomeprazole sodium drugs were dissolved with 30% acetonitrile-water（volume fraction）,and then separated on an Agela VenusiL MP-C18 column（21 mm×100 mm,3 μm）by gradient elution using water-acetonitrile as mobile phases at a flow rate of 0.2 mL/min,a column temperature of 35 ℃ and an injection volume of 1 μL.The detection of analytes was performed in the negative electrospray ionization mode（ESI-）under multiple reaction monitoring（MRM）mode.As a result,the calibration curves for GTI E and GTI I showed good linearities in the ranges of 1.26-44.8 μg/L and 1.34-45.2 μg/L,with their correlation coefficients of 0.994 7 and 0.992 8,respectively.The limits of detection（S/N=3）and limits of quantitation（S/N=10）of the method were 0.381 and 0.384 μg/L,and 1.26 and 1.34 μg/L,respectively.The spiked recoveries for GTI E and GTI I were in the ranges of 86.3%-87.6% and 85.8%-91.4%,with the relative standard deviations（RSDs）of 1.5%-2.2% and 0.7%-4.0%,respectively.The method has the advantages of simple operation,high sensitivity,good reproducibility,and could be used for the simultaneous detection of two potential genotoxic impurities including GTI E and GTI I in esomeprazole sodium.关键词：high performance liquid chromatography-quadrupole ion trap mass spectrometry（HPLC-QTRAP-MS/MS）;esomeprazole sodium;potential genotoxic impurities
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发布时间： - 摘要：An analytical method based on dispersive solid phase extraction/liquid chromatography-tandem mass spectrometry（dSPE/LC-MS/MS） was developed for the determination of amitraz,semiamitraz（DMPF） and their metabolites N-（2,4-dimethylphenyl） formamide（DMF） and 2,4 dimethylaniline（DMA） residues in royal jelly.The royal jelly samples were diluted with a buffer solution（pH 9.0） ,and the protein in royal jelly was precipitated with acetonitrile and NaCl.The acetonitrile supernatant was cleaned up with primary secondary amine（PSA） ,C18 and anhydrous MgSO4 by dSPE method,then the supernatant solution was filtered through a nylon membrane（0.22 μm） into a glass LC vial for LC-MS/MS analysis.The solution was separated on an Agilent Eclipse XDB-C18 column（150 mm×4.6 mm,5 μm） with acetonitrile-0.15%formic acid solution as mobile phases by gradient elution,then determined by LC-MS/MS with electrospray ionization（ESI） in positive ion scanning mode under multiple reaction monitoring（MRM） mode,and finally quantified by isotope internal standard method.Results showed that there were good linear relationships for amitraz,DMPF,DMF and DMA in the concentration range of 0-100 μg/kg with their correlation coefficients（r） more than 0.996.The limits of quantitation（S/N=10） for the analytes were 0.10,0.25,5.0 and 2.5 μg/kg,respectively.The spiked recoveries at three levels of 5,10 and 20 μg/kg were in the range of 77.0%-107%with relative standard deviations（RSD） of 2.0%-11%.This method was rapid and convenient,and was suitable for the simultaneous determination of amitraz,DMPF and their metabolites residues in royal jelly samples.
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发布时间： - 摘要：A method of ultrahigh performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） was developed for the simultaneous determination of five alkaloids,including peimisine,sipeimine,peiminine,peimine and sipeimine 3β-D-glucoside in Fritillaria.Samples were extracted with alkaline methanol-chloroform,and separated on an Acquity UPLC BEH C18 column using acetonitrile solution containing 0.1% formic acid as mobile phase by gradient elution.The target compounds were determined by UPLC-MS/MS under multiple reaction monitoring（MRM） mode,and then quantified by external standard method.The calibration curves showed good linearities in the range of 0.000 5-0.05 mg/L with correlation coefficients（r） greater than 0.999.Recoveries for the five alkaloids at three spiked levels(1.0,2.5,5.0 mg/kg) ranged from 78.6% to 93.1%,with relative standard deviations（RSD） not more than 8.6%.The limits of detection（LOD） and limits of quantitation（LOQ） were 0.03 mg/kg and 0.1 mg/kg,respectively.The established method was simple,sensitive,accurate and reliable,and could be applied in the simultaneous determination of the five alkaloids in Fritillaria.关键词：Fritillaria;alkaloid;ultrahigh performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）
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发布时间： - 摘要：A new method for the highly selective determination of citrulline in the melon pulp was established by capillary electrophoresis coupled with electrogenerated chemiluminescence detection （CE-ECL）,based on the N methylation derivatization reaction of the α-amino groups in citrulline molecules,with formaldehyde and sodium borohydride as main derivatization reagents to obtain a single derivative product emitting a strong electrochemiluminescence signal.Under the optimized experimental conditions,the citrulline derivative could be separated within 5 min,and there existed a good linear relationship（r2=0.999 6）between the electrophoretic peak intensity of the derivative and the original concentration of citrulline in range of 9.0-250 μmol/L with the detection limits of 3.2 μmol/L（S/N=3）.The relative standard deviations of peak height and migration time for the same standard sample（n=6）were 2.6% and 0.92%,respectively.Additionally,four kinds of actual melon samples were quantitatively determined by the standard addition method.Results showed that the citrulline contents in fresh melon pulp tissues of watermelon,melon,seeding melon and cantaloupe melon were 2.75,0.95,1.26 and 1.19 mg/g,respectively,while the recoveries for these real samples were between 91.4% and 106%.关键词：pre-column derivatization;capillary electrophoresis;electrochemiluminescence;citrulline;tris（2,2′-bipyridyl）ruthenium（Ⅱ）
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发布时间： - 摘要：In this paper,a new fluorescent carbon quantum dots（CQDs）were synthesized by one-step method using rapeseed and water as raw material.The experiments showed that potassium permanganate（KMnO4）could effectively quench the fluorescence of the CQDs.However,the fluorescence of CQDs-KMnO4 system restored reversibly in the presence of minocycline hydrochloride.Based on this principle,a new method was proposed for the determination of minocycline hydrochloride with the“off-on”fluorescence signal of rapeseed CQDs as a fluorescent probe.Under the optimum conditions,the linear range of the method was 5.0×10-7 mol/L to 1.0×10-5 mol/L with a correlation coefficient of 0.999 5 and a detection limit of 4.9×10-7 mol/L.The method was used in the determination of minocycline hydrochloride in samples with a recovery of 99.6%-100%.The mechanisms for CQDs fluorescence quenched by KMnO4 and recovered by minocycline hydrochloride were studied.关键词：carbon quantum dots;rapeseed;minocycline hydrochloride;“off-on”fluorescent probe;potassium permanganate
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发布时间： - 摘要：A new colorimetric method based on paper chip was established for the rapid detection of L-Cysteine（L-Cys） using 5,5'-dithiobis-（2-nitrobenzoic acid）（DTNB） as derivatizing agent.A normal phone was used to record the color intensity.The color intensity was analyzed by Photoshop software and used to calculate the concentration of thiol contained molecules in samples.The optimum coloration conditions for the detection were investigated.Results showed that there was a good linear relationship between color intensity and L-Cys concentration in range of 0.01-0.1 mmol/L with the linear correlation coefficient of 0.999 8 and the detection limit of 0.001 mmol/L.In the range of ±5%,the interference of several amino acids and ions on the determination of L-Cyse was small.The method was applied in the detection of L-Cys content in bovine serum sample with a result of 0.013 mmol/L and a spiked recovery of 99.1%-103%.Results showed that this method has high selectivity and reproducibility.The colorimetric method based on paper based microfluidic chip has several advantages such as simplicity,low reagent consumption,rapidness and repeatability.关键词：paper based microfluidic chip;thiol contained molecules;5,5'-dithiobis-（2-nitrobenzoic acid）（DTNB）;colorimetric method
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发布时间： - 摘要：A pyrroloquinoquinone（PQQ）-dopamine（DA）magnetic nanoparticle imprinted polymers were prepared by the combination of PQQ-DA and magnetic nano Fe3O4 as the core wrapped with SiO2,which possess high recognition and high selectivity toward PQQ-DA and have great advantages in the separation,purification and enrichment of low concentration compounds in complex matrix of brain tissue after molecular imprinting modification.The magnetic nanoparticles were applied in the determination of trace PQQ-DA in brain tissue samples by ultrahigh performance liquid chromatography-tandem mass spectrometry（UPLC-MS）.Results showed that,under the optimized conditions,there was a good linear relationship for PQQ-DA in the range of 0.02-0.1 mg/mL with a correlation coefficient（r2）of 0.996 6,and the detection limit was 0.2×10-11 mg/mL.The recoveries for brain tissue samples were in the range of 887%-955%,with relative standard deviations（n=6）of 2.6%-3.2%.The method could be used in the detection of trace PQQ-DA in vivo with high sensitivity and good repeatability.关键词：magnetic nanoimprinting;pyrroliquinoline quinone-dopamine（PQQ-DA）;ultra performance liquid chromatography-mass spectrometry（UPLC-MS）;solid phase extraction;trace products
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发布时间： - 摘要：Pesticide residues resulting from high dosage of pesticides in agricultural production are increasingly threatening human life and health.In that case,researchers are devoted to developing simple new techniques for the quantitative detection of pesticide residues.Carbon quantum dots are a new type of fluorescent carbon nanoparticles with excellent optical properties and biocompatibility,which are easy to realize surface functionalization.Therefore,fluorescent probes based on carbon quantum dots have a good application potential in detection of pesticide residues.In this paper,the research on carbon quantum dot based fluorescent probes is reviewed,the characteristics and synthesis of carbon quantum dots are briefly presented,the latest application progress of carbon quantum dots as fluorescent probes in pesticide residues detection is detailedly introduced,and the problems that have yet to be resolved are summarized.Finally,the future development direction is also forecasted.关键词：carbon quantum dots;fluorescent probes;pesticide residues;detection
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发布时间： - 摘要：Vitamin D is a fat soluble vitamin essential to human health,of which 25 hydroxyvitamin D is the major circulation and storage mode in human body.Dietary intake is an important way to obtain vitamin D and 25-hydroxyvitamin D for human.The pretreatment methods for vitamin D and 25-hydroxyvitamin D in foods usually include alkaline saponification,organic solvent extraction and purification by solid phase extraction or semi preparative chromatography.Traditionally,radioimmunoassay technique and high performance liquid chromatography were used for the determination of vitamin D and 25-hydroxyvitamin D in foods.Nowadays,liquid chromatography tandem mass spectrometry with higher accuracy and precision has become one of the most important methods in determination of vitamin D and 25-hydroxyvitamin D in foods.Recently,two dimensional liquid chromatography and ultrahigh performance supercritical fluid chromatography have gradually showed a powerful potential in detection of vitamin D and 25-hydroxyvitamin D in foods for their great separation abilities.The determination techniques for vitamin D and 25-hydroxyvitamin D and their content distributions in animal and plant foods are summarized in this review,in order to provide a reference for future studies such as developing suitable determination methods for different kinds of foods,determining their contents,providing reasonable diet suggestions for residents and dietary intake assessment.关键词：vitamin D;25-hydroxyvitamin D;foods;determination;content distribution
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