最新刊期
卷 41 ， 期 1 ， 2022
- 摘要：Electrochemiluminescence（ECL） refers to the luminescence process，in which excited luminophores are generated by electrochemical reactions and sequential chemical reactions.Generally，ECL can be generated through either the annihilation or the coreactant route，which is a surface-confined luminescence process．The thickness of ECL layer is controlled by the distribution of reaction intermediates near the electrode surface．Meanwhile，spatially resolved measurements are capable of directly measuring the distribution of excited luminophores or coreactant radicals in the vicinity of electrode surface，holding great promise for deciphering the ECL mechanisms．In this review，the research progress on ECL and the reaction mechanisms of different ECL systems are first briefly introduced．Then the applications of spatial resolution measurements，including scanning electrochemical microscopy，ECL microscopy and ECL self-interference spectroscopy in unraveling the mechanisms for ECL generation are summarized．Finally，perspectives and challenges in mechanistic studies of ECL generation are presented．关键词：electrochemiluminescence（ECL）;reaction mechanisms;spatially resolved measurements;ECL microscopy
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发布时间：2023-01-04 - 摘要：With the merits of high sensitivity，specificity，and analytical throughput，mass spectrometry has been recently applied to in-situ monitoring and mechanistic studies of electrochemical reaction processes．In the past decades，a series of electrochemical mass spectrometry（EC－MS） analysis methods have been developed by advancing novel ionization sources and interfacing electrochemical cell with mass spectrometers，which have exhibited excellent performance in the real-time monitoring of electrochemical processes，isotope labeling analysis，capture short-lived intermediates and other aspects．In this review，the methodological progress of EC－MS in the past five years is reviewed in three aspects：gas and volatile product analysis，liquid product analysis and short-lived intermediates identification．The applications of EC－MS in the monitoring of electrocatalytical systems and mechanistic studies of electrochemical reactions are also summarized．关键词：electrochemical mass spectrometry（EC－MS）;in-situ analysis;mechanistic study;electrocatalysis
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发布时间：2023-01-04 -
Advances on Applications of Supramolecular Solvents in Sample Pretreatment and Analytical Techniques
摘要：With the introduction of concept of green analytical chemistry，the development and utilization of novel green solvents have become a hot topic in contemporary research．Application of green solvents replacing traditional organic solvents in sample pretreatment could reduce the harm to laboratory personnel and the environment．Supramolecular solvents（SUPRASs） have been extensively used for the extraction and enrichment of the target analytes with wide polarity ranges in recent years due to their high-content amphiphilic substances and mild extraction and separation conditions，achieving both extraction and clean-up effects．In this paper，the formation process and basic properties of SUPRASs are introduced．Their advantages in extraction and separation are summarized. The applications of SUPRASs in sample pretreatment are reviewed，including the extraction of target substances by SUPRASs alone or in combination with other pretreatment methods．Combinations of SUPRASs-based extraction with various analytical techniques are also summarized．A systematic overview on the research advances of SUPRASs in sample pretreatment and analytical techniques may provide a theoretical guidance or technical support for their further development and utilization．关键词：supramolecular solvents（SUPRASs）;sample pretreatment;analytical techniques;review- 5
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发布时间：2023-01-04 - 摘要：In recent years，with the development of multiple-collector inductively coupled plasma mass spectrometry（MC－ICP－MS），metal isotope analysis has gradually become an effective tool to study the cycle of metal elements，understanding their migration and transformation，and tracing pollution. However，metals and nonmetals in the environment typically exist with different chemical speciation，so the development of new methods for on-line analysis of species－specific stable isotopes will open a new perspective for better understanding the element cycle and various chemical and biological processes．Combination of chromatography with MC－ICP－MS has attracted an increasing attention in recent years as it could realize the online separation of matrix and interference elements in the sample，greatly reducing the time of sample pretreatment，saving the cost，reducing the cross-contamination that may occur in the process of sample separation and purification，and accordingly making it possible to quickly obtain high-precision isotope ratio．Furthermore，it could also obtain the species－specific stable isotope composition of different elements，which is helpful to better understand the biogeochemical cycle of different element speciation，providing ideas and tools for understanding and solving geological，life and environmental problems．In this paper，the representative work on isotope analysis by chromatography coupled to MC－ICP－MS from 2000 to 2021 is reviewed．The transient signal processing methods and mass bias correction methods affecting the chromatography coupled to MC－ICP－MS are discussed and summarized．Finally，the applications of this method in geochemical，environmental and biological fields are also briefly summarized，and the development of isotopic analysis by chromatography coupled to MC－ICP－MS is prospected.关键词：chromatography;multiple-collector inductively coupled plasma mass spectrometry（MC－ICP－MS）;species－specific stable isotopes;metal stable isotopes
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发布时间：2023-01-04 - 摘要：Viruses rely on host cells to complete their life cycle and affect all living beings on the Earth. They are one of the main reasons for human disease，causing severe impacts on human health and the social economy．Thus，it is essential to exploit detection techniques for prevention of viral infections and treatment of viral diseases．The virus genome plays a crucial role in the life cycle of the virus，providing an effective target for the detection of the virus．G-quadruplex（G4） is a nucleic acid secondary structure with two or more stacked G-quartets formed by G-rich sequences via Hoogsteen hydrogen bonding．G4 involves in the regulation of multiple biological functions and plays a vital role in important cellular physiological processes．The explosive growth of G4-specific probes provides indispensable key components for the construction of G4 biosensing methods，the detection of G4 structure，and cell imaging．As a signal output，G4/probe complexes have been widely used in biosensing．Several methods are capable of label－free detection of a variety of viral gene sequences，showing great potential in the diagnosis and clinical analysis of viral diseases．Additionally，G4s widely exist in the viral genome and have become a potential target for imaging viral genes. Therefore，the application of G4 probes in developing virus detection methods is reviewed in this paper，the physiological role of G4 structure in a variety of viruses is introduced，and the virus genome visualization based on the G4 probe is summarized．Finally，the challenges and development trends in the detection of virus are summarized and prospected.关键词：virus;G-quadruplexes probes;detection;imaging
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发布时间：2023-01-04 - 摘要：As the most widely studied epigenetic modification in DNA，5⁃methylcytosine（5mC） plays an important role in the growth and development of organisms．5mC participates the regulation of gene expressions without changing the sequences of genes．Investigation on the localization and content changes of 5mC in the incidence of diseases will strengthen our understanding toward its roles in the development of diseases．Elucidation of the biological functions of 5mC mainly depends on uncovering its accurate localization information in genomes．Over the past few decades，many analytical methods based on high⁃throughput sequencing technology have been established to localize 5mC in genomes．Apart from the classic BS⁃seq（bisulfite sequencing），some other analytical methods，such as DIP⁃seq（DNA immunoprecipitation sequencing），EM⁃seq（enzymatic methyl⁃seq），TAPS（TET⁃assisted pyridine borane sequencing），nanopore⁃seq（nanopore sequencing） and SMRT⁃seq（single molecule real⁃time） have been developed．In this review，the principles，advantages and disadvantages of these analytical methods for 5mC localization in DNA based on the high⁃throughput sequencing technology are summarized and discussed.In addition，the future research directions for mapping 5mC in DNA are also envisioned.It is hoped that this review will benefit and stimulate the study of the biological functions of 5mC in genomes.关键词：methylated DNA modification;5⁃methylcytosine;location analysis;sequencing
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发布时间：2023-01-04 - 摘要：Protein SUMOylation is one of the most important post-translational modifications，which involved in various biological processes，including nuclear transport，transcriptional regulation，maintenance of gene integrity and cell cycle．However，identification of SUMOylation has always been the hotspot and difficulty in this field due to the low abundance and lengthy peptide sequence of endogenous SUMOylation．Therefore，the efficient enrichment of SUMOylated proteins/peptides is necessary to achieve deep coverage analysis of SUMOylome．The basic principles，characteristics and latest progresses of different enrichment methods for SUMOylated proteome are reviewed，and the development prospects are prospected.关键词：SUMOylation;deep coverage;enrichment;detection
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发布时间：2023-01-04 - 摘要：Clenbuterol is mainly used to treat asthma clinically，but it is also illegally abused in animal husbandry and sports due to its anabolic effect．The abuse in animal husbandry will lead to the residue of the drug in animal muscle or other edible tissues．Ingestion of this kind of contaminated meat by mistake will trigger the positive event of doping control．The number of positive cases of clenbuterol has been at the top of positive substances list every year since 2014，and the vast majority of positive cases are related to the accidental consumption of meat food contaminated by clenbuterol．How to distinguish whether it is food contamination or doping abuse of clenbuterol in doping control has been an international problem．Therefore，clenbuterol has once again become a hot spot in sports．In order to comprehensively sort out the research progress of the determination methods for clenbuterol and its development direction in sports，laying a foundation for further related work in the future，the determination methods of clenbuterol and its abuse in sports are summarized through consulting the literatures in recent ten years.关键词：clenbuterol;anabolic effect;doping;determination method
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发布时间：2023-01-04
Reviews
- 摘要：Nanomaterials have exhibited great potentials in the field of biological diagnosis and treatment．Recently，the design of an ideal drug delivery system with targeted recognition and controlled release，especially triggered by exclusive endogenous stimulus，has obtained great attentions．Meanwhile，silica based nanomaterials have attracted tremendous attention in biomedical applications in the past decades due to their superior biocompatibility and controllable structures．Developing a silica based nanoparticles mediated drug delivery system for transporting therapeutics to targeted sites and releasing them on demand has been one of most exciting research topics．Herein，the silica nanoparticles were selected for the construction based on the mesoporous silica nanoparticles’ advantages such as good biosafety and easy regulations on morphology，size，specific surface area，tunable pore sizes and easy functionalization．In addition，the surface of the material is easily functionalized due to the presence of silanol groups on the surface，which further improves the therapeutic effect of drugs and reduces the side effects．In this work，an aptamer-targeted silicon nanomaterial was constructed as a carrier for intracellular reagent delivery，ultra-sensitive detection of miRNA and controlled drug releases．Mesoporous silica nanoparticles（MSNs） at 55 nm were firstly prepared for the following functionalization and loadings by traditional stöber method．Thereafter，the hollow structure of MSNs was loaded with the anticancer drug doxorubicin（Dox）．In addition，the hairpin G－quadruplex DNA（HG1，HG2） was modified on the MSNs by electrostatic action to form a DNA gate to prevent the leaking of Dox．Therefore，in the tumor cells with the presence of miRNA－21 target，the cyclic amplification was triggered with HG1 and HG2．HG1 was employed to recognize and hybridize with miRNA－21，producing a single stranded tail in HG1，which dissociated and increased the mobility of HG1 on MSNs，facilitating its hybridization with HG2．HG2 met unfolded HG1 and initiated hairpin assembly，yielding double strand G－quadruplex（dsG） DNA to result in the signal amplification for the sensitive target detections．In this process，miRNA－21 could also serve as an exclusive key to release Dox by competing against DNA on surface of MSNs．This was achieved by the fully hybridization of miRNA－21 with HG1 and HG2 on MSNs surface，which thereby triggered on-command release of Dox from Dox@MSNs－DNA．As a result，the limit of the detection was 0.04 nmol/L for miRNA－21 detection．Therefore，maximum therapeutic efficacy and minimum side effects were achieved by virtue of the aptamer-targeted delivery and miRNA-targeted drug release．Endowed with highly specific and sensitive detection and controllable release of drugs，this multifunctional nanomaterial show a certain potential in diagnosis and treatment.关键词：mesoporous silica nanoparticles;cyclic amplification;controlled release;miRNA
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发布时间：2023-01-04 - 摘要：A comprehensive two-dimensional gas chromatography－quadrupole time-of-flight mass spectrometry（GC × GC－QTOF MS） was developed for the high-throughput analysis of volatile components in essential oils from Radix Angelicae Pubescentis（RAP）．The samples were directly separated and analyzed by GC × GC method after steam distillation．Subsequently，a total of 207 compounds were tentatively identified based on mass spectral library match，retention index comparison and accurate mass confirmation．In addition，a majority of the identified compounds have forward or reverse match factors greater than 800，while the errors between the measured value（accurate mass） and the true value（exact mass） of the identified compounds were within 3 ppm. In retention index（RI） confirmation，RI errors between the experimental measured value（RIexp） and the literature value（RIlit） were within 20 for more than 80% compounds．In the meantime，a semi-quantitative analysis indicated that esters，alcohols，phenols and hydrocarbons are the dominant chemical components in essential oils of RAP，which is important for the exploitation of chemical composition and medicinal value of RAP essential oils.关键词：comprehensive two-dimensional gas chromatography combination with quadrupole time-of-flight mass spectrometry;Radix Angelicae Pubescentis;volatile essential oil;chemical composition
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发布时间：2023-01-04 - 摘要：An ultra⁃high performance liquid chromatography－tandem mass spectrometric（UPLC－MS/MS） method was developed for the detection of 14 organophosphate esters（OPEs） and their 8 diester metabolites（di-OPEs） in cereal samples in this paper，and the pre⁃treatment process of purification was optimized．The cereal samples were ultrasonically extracted with methanol three times，and then purified directly with ENVI－18 cartridges without solvent conversion and eluted with 5 mL methanol．The combined eluent was concentrated under nitrogen．Finally，the analytes were analyzed by UPLC－MS/MS and quantified by the internal standard method．The analytes were separated on an Acquity UPLC BEH C18 column by gradient elution using methanol and 5 mmol/L ammonium acetate aqueous solution as mobile phases，and ionized in electrospray ionization positive mode for OPEs and negative mode for di-OPEs under the multiple reaction monitoring（MRM） mode．Results showed that there were good linear relationships for all compounds in the range of 0.1－20 μg/L，with their correlation coefficients（r） greater than 0.99．The detection limits（LOD） and quantitation limits（LOQ） for OPEs and di⁃OPEs were in the range of 0.005 02－1.94 ng/g and 0.016 7－6.45 ng/g，respectively．The average recoveries（n = 3） for 22 compounds in cereal samples at three spiked levels of 5，10 and 20 ng/g ranged from 60.0% to 131% except BBOEP（141%），with relative standard deviations（RSD） of 0.57%－22%．The optimized method was applied to the quantitation of OPEs and di-OPEs in 25 wheat samples．The total contents of 14 OPEs were in the range of 0.843－23.5 ng/g．Four OPEs（TEP，TCEP，TCIPP and EHDPP） were detected in all samples，while TCIPP was the main OPEs．The total contents of 8 di-OPEs were in the range of 0.126－4.81 ng/g，and the detection frequencies for 4 di⁃OPEs（DBP，DPHP，BEHP and BDCPP） were higher than 50%，while BEHP was the main di⁃OPEs．These results indicated that these OPEs and di⁃OPEs were widespread in cereal samples．Based on the measured OPEs and di-OPEs contents， the estimated daily intakes（EDIs） of Σ14OPEs via cereal intake were in the range of 4.23－118 ng/kg bw/day and 5.56－155 ng/kg bw/day for Chinese adults and children，respectively．The daily intake of 8 di-OPEs were in the range of 0.633－24.2 ng/kg bw/day and 0.832－31.7 ng/kg bw/day for adults and children，respectively．Overall，the EDIs through wheat intake were much lower than the Reference Dose（RfD） of OPEs．However，considering that the processing and transportation may introduce more OPEs and their metabolites into the wheat and there exists the possibility of other food contaminated by OPEs or di-OPEs，the human exposure to OPEs and di-OPEs through diet should be concerned.关键词：organophosphate ester;ultra-high performance liquid chromatography－tandem mass spectrometry;cereal;solid phase extraction
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发布时间：2023-01-04 - 摘要：In this article，selenium（Se） compounds were extracted from Se-enriched Cardamine Violifolia（C. Violifolia） by enzymolysis method，and the known Se species were determined by high performance liquid chromatography－inductively coupled plasma mass spectrometry（HPLC－ICP－MS）．As for the identification of unkown Se compounds，the enzymatic hydrolysate was firstly concentrated by removing impurities with a 3 kDa ultrafiltration centrifuge tube，then freeze－dried，and finally suspended in the initial mobile phase．A Kinetex F5 column（100 mm × 2.1 mm，2.6 μm） was selected for gradient elution．Mobile phases A and B were water and acetonitrile both prepared with 0.1%（volume fraction） formic acid．The unknown Se compounds were screened and identified by ultrahigh performance liquid chromatography－electrospray ionization high resolution tandem mass spectrometry（UPLC－ESI－Triple TOF MS）using unique isotope patterns，TOF MS and TOF MS/MS．The results showed that five Se species in C. Violifolia were determined by HPLC－ICP－MS，namely selenocysteine（SeCys2），methylselenocysteine（MeSeCys），selenomethionine（SeMet），selenite［Se（Ⅳ）］ and selenate［Se（Ⅵ）］．15 other Se compounds，including 7 reported and 8 unreported Se compounds，were identified by UPLC－ESI－Triple TOF MS．The structural formula of three unreported Se compounds，C4H7NO2Se，C5H8O2Se and C7H9NO2Se were proposed.关键词：selenium-enriched Cardamine Violifolia;selenium compounds;HPLC－ICP－MS;UPLC－ESI－Triple TOF MS;identification
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发布时间：2023-01-04 - 摘要：Top-down（TD） mass spectrometry（MS） could offer accurate and rich biological information at the molecular level by dissociating the complete protein ions in the gas phase. In this paper，a 3 µm infrared laser and a 210 nm ultraviolet laser were combined to introduce into the cell of an Fourier transform ion cyclotron resonance mass spectrometer（FT－ICR MS），and the top-down mass spectra for ubiquitin protein ions were obtained for the first time．The sequence coverages of the protein ions could be further optimized by optimizing the time series of two applied lasers．Experimental results showed that the dissociation could be better realized by introducing two laser beams into the ICR cell through the partial overlap in their time series．For +11 ubiquitin ions，the sequence coverages produced by the double-beam photodissociation method reached to 73%，higher than the results obtained by infrared multiphoton dissociation（IRMPD） or ultraviolet potodissociation（UVPD）．For ubiquitin ions with other charge states，similar results were observed，indicating that the new method could generate richer fragmentation patterns for protein ions than UVPD or IRMPD solely and improve sequence coverages of protein ions.关键词：top-down;ion activation;infrared multiphoton dissociation（IRMPD）;ultraviolet photodissociation（UVPD）;ubiquitin;Fourier transform ion cyclotron resonance mass spectrometer（FT－ICR MS）
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发布时间：2023-01-04 - 摘要：A chemiluminescence enzyme immunoassay（CLEIA） method was established for the monitoring of tiamulin residues in egg samples，based on a monoclonal antibody with excellent specificity and sensitivity obtained by synthesizing antigen to immunize BALB/c mice and cell experiments.The optimal conditions were finalized as follows：the coating antigen concentration：0.26 μg/mL，the antibody concentration：0.94 µg/mL，the reaction buffer system：PBS（0.02 mol/L，pH 7.4），and the dilution buffer，the concentration and the reaction time for the enzyme-labeled secondary antibody were PBST buffer，2 µg/mL and 40 min，respectively.Under the optimal conditions，a CLEIA method for tiamulin detection was established，with an IC50 of 0.54 ng/mL，a limit of detection（LOD，IC10） of 0.03 ng/mL，and a linear detection range （IC20-IC80） of 0.17－1.74 ng/mL.There was no obvious cross-reaction between the method and the other structural and functional analogs of tiamulin.The CLEIA method was used for the detection of real egg samples.The spiked recoveries ranged from 100% to 118%，with the relative standard deviations（RSDs） less than 10%. The test results of the developed CLEIA had a good correlation with those of HPLC－MS/MS（r2 = 0.998 7），indicating that the method was suitable for the detection of tiamulin residues in egg samples.关键词：tiamulin;egg;monoclonal antibody;chemiluminescene enzyme immunoassay（CLEIA）
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发布时间：2023-01-04 - 摘要：To investigate the quality difference of sinomenine hydrochloride prepared with different extraction solvents and explore the feasibility of changing the extraction process，the quality of sinomenine hydrochloride samples prepared by benzene and acid water percolation－chloroform extraction were systematically evaluated using near-infrared spectroscopy，Raman spectroscopy combined with multi-source data fusion technique．Subsequently，the potential effects of the two solvents on product were compared．The overall quality of the samples were characterized with the different statistics named similarity matching value（SMV），Hotelling T2 and DModX，under three fusion modes of low，medium and high levels．Under the low level fusion mode，the results showed that the DModX values of nine samples exceeded the control limit．Under the medium level fusion mode，the SMV of one sample was lower than the control limit．Under the high level fusion mode，the SMVs of three samples were below the control limit，and the DModX values of five samples were above the control limit. Compared with the samples obtained by acid water percolation－chloroform extraction（obtained from manufacturer A），the quality consistency of the samples prepared by benzene（obtained from manufacturer B） and chloroform extraction（obtained from manufacturer C） is good，except that several samples need arbitration analysis for quality confirmation．In the process of sinomenine extraction，chloroform with low toxicity could be used to replace benzene which is harmful to human health．The study is aimed to develop a new strategy for evaluating the quality difference of traditional Chinese medicine products before and after the change of preparation process．关键词：sinomenine hydrochloride;multi-source data fusion technique;near-infrared spectroscopy;Raman spectroscopy;process change
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发布时间：2023-01-04 - 摘要：Carmine is one of the most widely used synthetic pigments in foods．However，a certain dose of carmine may result in teratogenicity，sensitization，neurotoxicity，reproductive and developmental toxicity．In order to develop a simple，rapid and accurate analytical method for screening carmine residues in food，a novel hapten against carmine was designed and synthesized in this paper. It was conjugated to lactoferrin by diazotization method to obtain immunogen and bovine serum albumin by glutaraldehyde method to obtain coating antigen．After immunizing the Bal b/c mice by immunogen，the spleen cells were fused with SP 2/0 to obtain the hybridoma screening monoclonal antibodies with high specificity to carmine．Negligible cross-reactivity with carmine analogous such as amaranth，lemon yellow，brilliant blue and sunset yellow was obtained．Based on the obtained monoclonal antibody，a simple，rapid and sensitive indirect competitive enzyme-linked immunosorbent assay（icELISA） was developed and validated. After optimizing the working conditions，the proposed icELISA showed a good sensitivity for carmine detection， with a half inhibition rate（IC50） of 10.1 ng/mL，a limit of detection（IC10） of 0.98 ng/mL and a linear range of 2－50 ng/mL．The proposed assay was then applied to detection of carmine in sprite and hawthorn strips samples．Recoveries of 93.0%－100% for sprite samples and 93.0%－113% for hawthorn strips samples were obtained with relative standard deviations of 3.2%－3.9% and 9.7%－12%，respectively，which were validated by standard high performance liquid chromatography coupled with ultraviolet-visible spectroscopy（HPLC－UV）．Results showed that the proposed icELISA was an ideal tool for the rapid screening of carmine residues in food samples.关键词：carmine;hapten design;monoclonal antibody;indirect competitive enzyme-linked immunosorbent assay （icELISA）;food
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发布时间：2023-01-04 - 摘要：The abundance of excimer ion peaks could be decreased by the in⁃source fragmentation and neutral loss of molecule CO2 occurred within perfluoroalkyl ether carboxylic acids（PFECAs） under ESI source，which affects the detection sensitivity for PFECA. In this paper，［CF3（CF2）nO］ or ［M－H－CO2］ was selected as the parent ion，and fluorinated alkoxy and alkyl groups were selected as the daughter ions，which could increase the response of PFECAs by 4 orders of magnitude at most. Four PFECAs in water samples were detected by ultra⁃performance liquid chromatography－tandem mass spectrometry combined with liquid－liquid extraction. There were good linear relationships for the four analytes with their correlation coefficients（r2） larger than 0.99. The limits of detection and limits of quantitation were in the range of 0.001－0.005 ng/mL and 0.003－0.01 ng/mL，respectively. The spiked recoveries ranged from 90.2% to 108%，with relative standard deviations（RSD） not more than 7.9%. The method provides a platform for the accurate quantification and high sensitive detection of PFECAs.关键词：perfluoroalkyl ether carboxylic acid（PFECA）;ultra⁃performance liquid chromatography;mass spectrometry;in⁃source fragmentation;neutral loss of molecule CO2
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发布时间：2023-01-04 - 摘要：An ultrahigh performance liquid chromatography coupled with quadrupole orbitrap mass spectrometry（UHPLC/ESI－Q－Orbitrap） was established for the detection of selenomethionine in beans，by collecting the chromatographic information，mass charge ratio of molecular ion and mass charge ratio of fragmentation fragments of selenomethionine（SeMet） and analyzing the fragmentation pathway．The samples were firstly dissolved with Tris－HCl buffer solution，then blended well with a vortex mixer，followed by ultrasonic extraction and enzymatic hydrolysis under constant temperature bath with trypsin and protease K，and finally centrifuged．The supernatant was filtered through a 0.22 μm microporous membrane，and then determined using the UHPLC/ESI－Q－Orbitrap system．The extract was separated on an Hypersil GOLD HILIC column（50 mm × 2.1 mm，1.9 μm） by gradient elution，using 0.2%（volume fraction） formic acid－6 mmol/L ammonium formate aqueous solution and 0.2% formic acid－6 mmol/L ammonium formate acetonitrile solution as the mobile phases．The SeMet was determined in positive electrospray ionization mode（ESI） under Full MS/dd－MS2 acquisition mode，and quantified by matrix-matched standard calibration method due to the existence of matrix effect．The matrix effect for SeMet was 15.75%，evaluated by the ratio of solvent standard curve and matrix-matched standard curve．Under the optimal conditions，there was a good linear relationship for SeMet in the concentration range of 0.05－0.5 mg/L with a correlation coefficient（r2） of 0.997 6，while the limit of detection（LOD） and the limit of quantification（LOQ） were 0.015 mg/kg and 0.05 mg/kg，respectively．At three spiked levels of 0.1，0.2 and 0.4 mg/kg，the average recoveries for SeMet in mung bean ranged from 77.6%－83.2%，with the intra-day relative standard deviations（RSDr） and the inter-day relative standard deviations（RSDR） of 2.8%－4.8% and 4.1%－6.5%，respectively．This method was applied to the detection on actual samples collected in laboratory．The results showed that the contents of selenomethionine in selenium-enriched black bean，selenium-enriched red bean and selenium-enriched mung bean were 0.252，0.163 and 0.184 mg/kg，respectively．With the advantages of simple pretreatment，accurate result and good repeatability，this method is suitable for the detection of SeMet in beans.关键词：beans;selenomethionine;ultrahigh performance liquid chromatography coupled to quadrupole orbitrap mass spectrometry
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发布时间：2023-01-04
Scientific Papers
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