最新刊期
卷 42 ， 期 4 ， 2023
- 摘要：Fuke Zaizao pill consists of forty-two herbs，which is commonly utilized in clinic therapy for gynecological diseases．However，Fuke Zaizao pill has complicated chemical compositions that have not been adequately clarified，and its quality control needs to be improved．In this paper，an ultra fast liquid chromatography－ion trap time-of-flight mass spectrometry（UFLC－IT－TOF MS） was developed for rapid analysis of the chemical constituents in Fuke Zaizao pill．The gradient elution was performed on a COSMOSIL C18 column（3.0 mm × 150 mm，2.6 μm） with 0.4% acetic acid and acetonitrile as mobile phases．Positive and negative ion ESI modes were used simultaneously to collect MS1，MS2 and MS3 fragment information of Fuke Zaizao pill．A total of 155 chemical constituents were tentatively identified by deducing the mass spectrometric cleavage pattern，and comparing with standards，references and single herb chromatography，including 47 terpenoids，43 phenols and phenolic acids，39 flavonoids，14 alkaloids，8 phthalides，and 4 other structures，of which 133 components were firstly found in the Fuke Zaizao pill．The chemical composition of Fuke Zaizao pill was further elucidated in this paper，and a wealth of information for improving its quality standards and elucidating its effective components was provided.关键词：Fuke Zaizao pill;ultra fast liquid chromatography－ion trap－time-of-flight mass spectrometry（UFLC－IT－TOF MS）;chemical substance basis;quality evaluation;secondary development
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发布时间：2023-04-18 - 摘要：Ultra-performance liquid chromatography（UPLC） and ultra-performance liquid chromatography－triple quadrupole mass spectrometry（UPLC－QQQ－MS） were adopted for the simultaneous determination on 23 chemical ingredients in a total of 408 Salviae Miltiorrhizae Radix et Rhizoma（Danshen） samples from Shandong，Henan，Shaaxi，Sichuan and Anhui provinces，in order to compare and analyze the influences of origins on phenolic acids and tanshinones in Danshen．Meanwhile，the data were analyzed by multivariate statistics．The results showed that 17 phenolic acids and 6 tanshinones had significant differences in Danshen．The samples from Shandong province had the highest content of tanshinones，while the samples from Sichuan province had the highest content of salvianolic acid B，and the samples from Anhui province had the highest contents of lithospermic acid，salvianolic acid Y，salvianolic acid A，salvianolic acid D and salvianolic acid E．Various pattern recognition methods were used to identify and analyze Danshen from different origins，and linear discriminant analysis（LDA） was the best model for traceability．Orthogonal partial least squares－discriminant analysis（OPLS－DA） showed that the chemical constituents of Danshen from different origin areas were significantly different．Quality markers of Danshen from different sources were not limited to salvianolic acid B，tanshinone Ⅰ，cryptotanshinone and tanshinone ⅡA，other salvianolic acids and tanshinones were also important quality markers. In this paper，the multi-component content determination and data analysis of cultivated medicinal materials collected from different main origin areas of the country were carried out．The quantitative method established was highly specific，accurate and efficient，which provided a reference for the quality control and identification of Danshen from different producing areas.关键词：Salviae Miltiorrhizae Radix et Rhizoma;origin difference;content determination;chemometrics;quality evaluation
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发布时间：2023-04-18 - 摘要：An ultrahigh performance liquid chromatography－quadrupole time-of-flight mass spectrometry（UPLC－Q－TOF MSE） with UNIFI software analysis was used to analyze the chemical components in Zhuangyao Jianshen tablets．The active components were screened by ADMETlab and TCMSP database，of which 55 potential active components were found．The galic acid，protocatechuic acid and protocatechuic aldehyde were determined as the content determination index，based on the comprehensive evaluation of active components and the pharmacological activity literature related to the function of Zhuangyao Jianshen tablets．Meanwhile，a high performance liquid chromatography（HPLC） method was established to detect the contents of galic acid，protocatechuic acid，protocatechuic aldehyde in 15 batches of samples，which were 0.135 3－0.344 8 mg/g，0.430 8－0.946 3 mg/g and 0.042 4－0.107 7 mg/g，respectively．The HPLC fingerprints for 15 batches of Zhuangyao Jianshen tablets were established，15 common peaks were calibrated and attributed to the Chinese medicine of the prescription with their similarities between 0.988 and 1.000，which showed that the inter-batch consistency of ingredients were high．Compared with those in the original standard，the newly established analytical indexes in this paper could more comprehensively characterize and evaluate the quality of Zhuangyao Jianshen tablets，and provide a scientific basis for the effective material analysis and the improvement of the quality standard．It is of great significance to improve the quality controllability of the product.关键词：Zhuangyao Jianshen tablets;UPLC－Q－TOF MSE;material basis;quality standard;fingerprint;content determination
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发布时间：2023-04-18 - 摘要：A high-performance liquid chromatography－quadrupole time-of-flight mass spectrometric（UPLC－Q－TOF MS） method was established to identify the constituents in Keke Tablets．The analytes was separated on a waters CORTECS T3 column（150 mm × 2.1 mm，1.6 μm） by gradient elution，with 0.1% formic acid water－acetonitrile as the mobile phase，and then analyzed in both positive and negative ions modes．Constituents in methanol－H2O extract of Keke tablets were identified by mass spectrometry database，fragmentation regularities of mass spectra，consulting literature reports，retention time and mass data of reference compounds．A total of 94 constituents were identified，including 33 alkaloids，22 flavones，9 phenylpropanoids，8 triterpenoid saponins，5 amino acids，3 cyanophoric glycosides，6 organic acids and 8 other compounds．Chemical constitutions of Keke tablets were comprehensively analyzed，which will be helpful to the quality control and pharmacodynamics material basis research.关键词：Keke Tablets;high-performance liquid chromatography－quadrupole time-of-flight mass spectrometry（UPLC－Q－TOF MS）;material basis;qualitative analysis
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发布时间：2023-04-18 - 摘要：Partial least squares discriminant analysis（PLS－DA） is currently a common method for biomarker screening in metabolomics research．However，it is often not ideal for finding the biomarkers in biomedicine，a class of complex non-linear research objects since it is a typical linear algorithm．Thus，a support vector machine approach based on unsupervised discriminative projection feature selection（UDPFS－SVM） is proposed in this paper．This method may be divided into two steps．The first step is to obtain the low-dimensional discriminant projection matrix．The UDPFS－SVM firstly introduces category prior information，then adding regularization and constraints such as penalty functions to obtain a discriminant projection matrix．Subsequently，the discriminant projection matrix is filtered by weights to become a low-dimensional discriminant projection matrix．The second step is to establish the support vector machine classification model．The UDPFS－SVM is used to build a support vector machine classification model based on the projection matrix to find biomarkers．It is worth mentioning that it is able to adaptively adjust the low-dimensional sparse projection matrix．Meanwhile， the UDPFS－SVM is able to perform both fuzzy and sparse learning，and it can also make reasonable use of the dependency relationships between variables．Therefore，it can handle non-linear research objects very well．In this paper，the metabolomic data of hyperlipidemic rats were screened for variables using the UDPFS－SVM and PLS－DA．And the biomarkers obtained from the screening were evaluated by variance analysis，ROC curves，and linear discriminant analysis（LDA）．The results showed that eight biomarkers were identified by each of the two methods．Variance analysis showed that the numbers of significant biomarkers obtained by UDPFS－SVM were more than those of PLS－DA．Furthermore，the significant difference values obtained by UDPFS－SVM were all larger than those by PLS－DA．ROC curves results showed that the ROC value of UDPFS－SVM was significantly higher than that of PLS－DA．The ROC value of UDPFS－SVM is 1.00，which is 0.05 higher than that of PLS－DA．The results of LDA showed that biomarkers obtained by UDPFS－SVM could better eliminate the intra-group metabolic differences in hyperlipidaemic samples，and it could more significantly differentiate inter-group metabolic differences in hyperlipidaemic samples．In summary，the UDPFS－SVM is superior to PLS－DA in the discovery of biomarkers for hyperlipidemia．Therefore，UDPFS－SVM is a relatively ideal marker screening method for dealing with the complex non-linear research subject of biomedicine．It improves the accuracy of screening for markers in biomedicine，a non-linear research subject．This method offers a new way for biomarker discovery in the era of precision medicine.关键词：variable screening;unsupervised discriminative projection;classified prior information;non-linear;high-dimensional and small samples;metabonomics
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发布时间：2023-04-18 - 摘要：Halogenated greenhouse gases（HGHGs） have a strong greenhouse effect due to their high global warming potential．However，the mixing ratios of ambient HGHGs are very low，and it is a challenge to accurately determine HGHGs in ambient air．A preconcentration gas chromatography－mass spectrometry with electron capture detector system（GC－MS/ECD） was established for the determination of 32 HGHGs in ambient air in this paper．The influences of capture flow，cold trap temperature and ECD temperature were investigated to obtain the optimal analysis conditions．Method validation experiments were carried out through the determination of 32 HGHGs．The results showed that good linear relationships in the range of 20－800 pmol/mol were obtained，and the correlation coefficients（r） for the 32 HGHGs were greater than 0.99．The method detection limits ranged from 0.21 pmol/mol to 1.17 pmol/mol，and the quantitation limits ranged from 0.84 pmol/mol to 4.68 pmol/mol．The spiked recoveries ranged from 92.5% to 104%，with relative standard deviations （RSDs） of 0.50%－6.4%．This method could satisfy the requirements for monitoring the HGHGs in ambient air，and it provides a reliable means for the analysis of HGHGs in ambient air.关键词：halogenated greenhouse gases;preconcentration;gas chromatography－mass spectrometry;gas chromatography－electron capture detector;ambient air
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发布时间：2023-04-18 - 摘要：A method for the determination of 12 pyrethroid pesticides in blood and liver by ultra performance liquid chromatography－quadrupole/electrostatic field orbittrap high-resolution mass spectrometry（UPLC－QE－Orbitrap HRMS） was developed．After acetonitrile precipitation，the blood and liver were separated by gradient elution on a Hypersil GOLD VANQUISH analytical column（1.9 µm，2.1 mm × 100 mm） with 5 mmol/L ammonium acetate（containing 0.1% formic acid） and methanol as mobile phase．Full scan and automatic trigger secondary mass spectrometry（Full MS/dd－MS2） were used for detection．The experimental results showed that the linearities of 12 pyrethroid pesticides were good in their linear range（r2 ≥ 0.990 4）．The limits of detection in blood and liver were in the range of 1－18 ng/mL and 1－18 ng/g，respectively．The limits of quantitation were 2－20 ng/mL and 2－20 ng/g，respectively．The matrix effects were 82.3%－117%，and the recoveries were 74.1%－120%．The intra-day RSD（intra-RSD） were not more than 11%，and inter-day RSD（inter-RSD） were not more than 12%．This method could meet the requirements of public security organs in handling actual cases and was suitable for the detection and identification of pyrethroid pesticides in blood and liver samples.关键词：ultra performance liquid chromatography－quadrupole/electrostatic field orbittrap high-resolution mass spectrometry（UPLC－QE－Orbitrap HRMS）;pyrethroids;blood;liver;detection
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发布时间：2023-04-18 - 摘要：By virtue of the strong adsorption on patulin，a graphitized carbon black-based solid phase extraction （SPE） cartridge（named as GCB cartridge） was fabricated in this paper．Meanwhile，the GCB cartridge was combined with high performance liquid chromatography－photodiode array detector（HPLC－PDA） and liquid chromatography－tandem mass spectrometry（LC－MS/MS） in turn to evaluate the cleanup effects of the home-made GCB cartridge and four commercial SPE cartridges（Retain AX，PAX，MAX and HLB），which were further applied to analysis on the various impurities in the clear apple juice that could affect the accurate quantification of patulin．The significantly improved chromatograms obtained，signal-to-noise ratios（S/Ns） and matrix effects displayed their capabilities in the decrease of impurity interference．Among them，the GCB cleanup provided an ideal chromatogram in HPLC－PDA analyses，as well as an acceptable matrix effect of -14%，a chromatogram superior to the HLB cleanup and a comparable S/N to the Retain AX cleanup in LC－MS/MS analyses．Consequently，a LC－MS/MS method with the stable isotope dilution assay（SIDA－LC－MS/MS） was developed to overcome the impacts of matrix effect and cleanup loss on the accuracy of test results．The performance characteristics of methods based on different SPE cleanups with HPLC－PDA and SIDA－LC－MS/MS，respectively，were compared．The results showed that the GCB cleanup provided a higher sensitivity than the HLB cleanup due to its lower limits of detection and quantitation，while the methods with MAX，HLB and GCB cleanup all showed better recoveries（82%－102%） and smaller relative standard deviations（≤ 9%）．The developed GCB cleanup only needed two steps（i.e. loading and elution） to carry out by gravity on a SPE manifold within 10 min，which is simpler and faster than other SPE cleanups．The powerful cleanup effects were also reflected in the pigment removal of eight familiar apple juices．Furthermore，some locally moldy apples were processed into the apple juice which was verified to be a positive sample of 34 μg·kg-1 patulin by the GCB cleanup and the analyses by HPLC－PDA and SIDA－LC－MS/MS，respectively．The better cleanup effects and lower cost of GCB cartridge would be helpful to its wide application in the routine detection of patulin.关键词：graphitized carbon black;patulin;apple juice;cleanup;HPLC－PDA;LC－MS/MS
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发布时间：2023-04-18 -
Colorimetric Detection of Uric Acid Using a Ratiometric Nanoprobe Based on Alginate-stabilized AgNPs
摘要：A ratiometric nanoprobe based on sodium alginate（SA）-stabilized silver nanoparticles（AgNPs） was constructed for the colorimetric detection of uric acid（UA） in urine samples in this paper．The SA functionalized AgNPs nanoprobe was prepared by a facile one-step synthesis method with NaBH4 as reducer and SA as stabilizer．Furthermore，the morphological and spectral properties of the as-obtained nanoprobe were carefully characterized by transmission electron microscopy（TEM），dynamic light scattering（DLS），Fourier transform infrared spectroscopy（FT－IR），X-ray energy dispersive spectroscopy（EDS），and ultraviolet－visible spectroscopy（UV－Vis）．It is found that SA could improve the dispersity and stability of AgNPs，and increase the surface plasma resonance at 400 nm．In the presence of UA，the nanoprobe could be induced to agglomerate via ligand exchange between the target and SA molecules，giving rise to a 530 nm absorption peak and leading to the color change from bright yellow to wine red．Consequently，a colorimetry-based ratiometric sensing strategy could be established.Meanwhile，the color evolution upon the exposure to UA offers the possibility for visualizing analysis of UA．In the optimized conditions，this designed nanoprobe yields a linear response to UA in the concentration range of 1.67 × 10-5－1.67 × 10-3 mol/L（r = 0.992），with a limit of detection（LOD） of 14.9 µmol/L．Moreover，the commonly coexisting inorganic ions and small biomolecules（e.g.，glucose，ascorbic acid，urea and creatinine） in urine samples cannot produce interference to UA detection，and the spiked recoveries for real urine samples ranged from 92.7% to 109% with relative standard deviations less than 1.0%. With the advantages of ecofriendly and simple preparation，as well as favorable specificity and stability，the present nanoprobe could provide a novel detection method for aiding diagnosis of UA-related clinical diseases such as hyperuricemia，gout，renal and cardiovascular diseases.关键词：silver nanoparticles;sodium alginate;uric acid;ratiometric nanoprobe;colorimetry- 10
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发布时间：2023-04-18 - 摘要：A gas chromatography－mass spectrometry（GC－MS） was established for the determination of 53 semi-volatile organic compounds in solid wastes，based on microwave-assisted extraction combined with solid phase extraction（SPE） column cleanup．Extraction was carried out in a microwave extraction tank using 20 mL acetone－hexane （1∶1，by volume） as the extractant，with an extraction temperature of 100 ℃ and an extraction time of 15 min，then the extract was concentrated by nitrogen blowing．The analyte was purified by magnesium silicate solid phase extraction column and separated on a DB－5MS（30 m × 0.25 µm × 0.25 mm） capillary column，finally detected with electron bombardment ionization source（EI） in selected ion monitoring（SIM） mode and quantified by internal standard method．The results showed that there were good linear relationships for 53 semi-volatile organic compounds in the range of 0.2－5.0 mg/L，with their correlation coefficients（r） not less than 0.998．The limits of detection for typical solid waste ash and biochemical sludge samples were in the range of 0.002－0.015 mg/kg and 0.004－0.027 mg/kg，while the limits of quantitation were in the range of 0.008－0.060 mg/kg and 0.016－0.108 mg/kg，respectively．For two typical solid waste negative sample matrices，the average recoveries at three spiked levels of 0.5，1.0 and 2.0 mg/kg for ash sample ranged from 70.7% to 98.5%，with relative standard deviations（RSDs，n = 6） of 1.7%－14%，while the average recoveries for biochemical sludge sample ranged from 71.8% to 105%，with RSDs（n = 6） of 1.2%－15%．The method was applied to the analysis of solid waste samples from Miluo pesticide plant，in which seven semi-volatile organic compounds，i.e．phorate，fenitrothion，heptachlor，hexachlorobenzene，p，p'-DDE，p，p'-DDT and mirex with different concentrations were detected．This method is rapid，accurate，environmentally friendly and reliable，and low reagent consumption，which could meet the requirements for high throughput detection of 53 semi-volatile organic compounds in solid waste，and significantly improve the detection efficiency for semi-volatile organic compounds.关键词：semi-volatile organic compounds;solid waste;microwave extraction;solid phase extraction;gas chromatography－mass spectrometry
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发布时间：2023-04-18
Scientific Papers
- 摘要：Xenon（Xe） isotopes from nuclear test and accidents are important monitoring components of the comprehensive nuclear test ban treaty（CTBT）．An approach for the reproducible and accurate compositional analysis of Xe isotope ratios by multiple collector inductively coupled plasma mass spectrometry（MC－ICP－MS） was described in this paper．A Xe enrichment and purification platform was established to separate Xe from the collected atmosphere gas，enriching the Xe concentration and utilizing high purity argon as aerosol carrier，thus resulting in eliminating the negative influences of organic compound and particles on mass spectrometry．A relible Xe injection system was built to control the gas flow rate between the sample and the MC－ICP－MS in order to improve the stability and reproducibility of the ion-signals．Furthermore，several measures，including adsorbing Xe from the sample gas for mass spectrometry and baking the Xe introduction device for 2 hours with vaccum pumping，were taken to reduce the Xe blank．As a result，the blank signal of 129Xe falled from 3.0 × 10-2 V to 2.7 × 10-3 V．Analyses were performed on a Neptune XT MC－ICP－MS，and standard sample bracketing（SSB） was involved in correcting the mass fractionation．The approach was successfully validated by the measurement of standard reference materials in 24 hours，showing that the relative uncertainties for all Xe isotope ratios were less than 0.09%（n = 7），while the results agreed with the certificated values within uncertainty range．Especially，the relative uncertainties for 130Xe/131Xe and 132Xe/131Xe ratios were 0.007 1% and 0.006 9%，respectively．Two kinds of atmosphere gas collected at different times were analyzed and distinguished successfully by the proposed approcach．The results demonstrated that the developed technique was a precise and accurate method for Xe isotope dectection，Xe monitoring event identification and event sourcing.关键词：xenon isotope ratios;Xe enrichment and purification device;Xe injection system;multiple collector inductively coupled plasma mass spectrometry（MC－ICP－MS）
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发布时间：2023-04-18 - 摘要：A new polydopamine modified titanium dioxide nano/submicro particles coating（PDA@TiO2NPs） was fabricated on the NiTi alloy wire by electrophoretic deposition and self-polymerization modification in this paper．Prior to electrophoretic deposition，the titanium and nickel oxide composite nanoflakes（TiO2NiOCNFs） were in situ grown on NiTi alloy wire via hydrothermal treatment in order to boost the binding strength between TiO2NPs coating and NiTi fiber. Coupled with high performance liquid chromatography（HPLC），the fabricated PDA@TiO2NPs@TiO2NiOCNFs@NiTi fiber was applied as a solid phase microextraction（SPME） fiber to the determination of 5 phthalic acid esters（PAEs） in water samples．The main parameters affecting extraction efficiency such as extraction temperature，extraction time，stirring rate and ion strength were investigated and optimized．Under the optimized conditions，the analytical parameters including linear ranges，recoveries，limits of detection（LODs） and limits of quantitation（LOQs） were investigated and evaluated by external standard method．The results showed that the proposed method showed good linearity in the range of 0.1－200 μg/L，with correlation coefficients（r） not less than 0.998 9．LODs and LOQs were in the range of 0.013－0.055 μg/L and 0.043－0.18 μg/L，respectively．The intra-day and inter-day relative standard deviations（RSDs） for each fiber ranged from 5.4% to 6.8% and 5.7% to 7.0%，respectively．Moreover，the developed method was successfully used to extract and detect trace PAEs in real water samples．The spiked recoveries for target PAEs in real water samples ranged from 87.8% to 102%，with RSDs not more than 8.2%．In addition，the established method has high sensitivity，good accuracy，which was suitable for the high efficient detection of PAEs in different environmental water samples.关键词：polydopamine;electrophoretic deposition;titanium dioxide nano/submicro particles;solid phase microextraction;high performance liquid chromatography;phthalic acid esters
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发布时间：2023-04-18 - 摘要：According to the formation of Hg2［Fe（CN）6］ nanozyme based on the in-situ reaction of Hg2+ and K4［Fe（CN）6］，a multifunctional biosensing platform was constructed based on an enzyme cascade in which the activity of Hg2［Fe（CN）6］ depended on hydrogen peroxide（H2O2），as well as pyrophosphate（PPi） was able to bind to Hg2+ and prevent the formation of Hg2［Fe（CN）6］ nanozyme．In the presence of glucose，glucose oxidase oxidized glucose to generate H2O2，and then Hg2［Fe（CN）6］ catalyzed the decomposition of H2O2 to produce hydroxyl radicals（·OH） to oxidize the substrate of 3，3'，5，5'-tetramethylbenzidine（TMB），which enabled the detection of glucose．The linear range of the method for glucose detection was 0.10－500 μmol/L，and the detection limit was 30 nmol/L．In the presence of acid phosphatase（ACP），ACP could hydrolyze PPi to release Hg2+ that could otherwise be bound by PPi，which allowed the reaction of K4［Fe（CN）6］ with Hg2+ to generate Hg2［Fe（CN）6］ nanozyme for catalyzing the oxidation of TMB．Results showed that the linear range of the method for the detection of ACP was 0.03－50 U/L，and the detection limit was 0.007 0 U/L．This sensing platform is different from the traditional detection system for single target，which provides a new idea for the design of multifunctional sensing systems with simple operation and high sensitivity.关键词：nanozyme;enzyme cascade system;Hg2［Fe（CN）6］;glucose;acid phosphatase（ACP）
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发布时间：2023-04-18 - 摘要：A novel urchin-like tungsten copper（U－WCu） self-supporting electrode for electrochemical detection of glucose was rapidly and efficiently fabricated by square wave pulse method on the surface of smooth W70Cu30 electrode in this paper．The U－WCu electrode showed a better electrochemical performance than the nano-copper（N－Cu）．Effects of pulse time，pulse frequency and potential range on the electrocatalytic oxidation of glucose were investigated in detail．Cyclic voltammetry（CV） was used to compare the electrocatalytic oxidation behaviors of glucose between U－WCu electrode and N－Cu electrode in 0.1 mol/L NaOH solution，and an enzyme-free electrochemical sensor based on the U－WCu electrode was constructed．The electrode has a wide linear range（2 μmol/L－10 mmol/L），a low detection limit（S/N = 3） for glucose（0.21 μmol/L） and a high sensitivity up to 4 983 μA∙mmol∙L-1∙cm-2．Moreover，the sensor exhibited excellent repeatability，reproducibility，stability and good anti-interference，and it was successfully applied to the determination of glucose content in glucose injection.关键词：urchin-like structure;glucose;electrocatalytic oxidation;electrochemical detection
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发布时间：2023-04-18
Experimental Techniques and Methods
- 摘要：It is of great significance to use accurate and reliable chromatography－mass spectrometry to screen and detect residues of pesticides，veterinary drugs，organic pollutants and other harmful substances in edible agricultural products．High-resolution mass spectrometry（HRMS） has higher resolution and accuracy quality in qualitative and quantitative detection on trace compounds in the complex food matrix．The technical characteristics of quadrupole/time-of-flight mass spectrometry（Q/TOF MS） and quadrupole/orbitrap mass spectrometry（Q/Orbitrap MS） are reviewed in this paper，and the applications of HRMS in detection of pesticide residues in plant and animal derived food at home and abroad from 2017 to 2022 are focused on. The development prospect of HRMS technology is discussed from three aspects，i.e. the development of HRMS technology，the technical requirements of food safety supervision departments and the third party testing institutions．In conclusion，chromatography－mass spectrometry has become the mainstream technology adopted in the national food safety standards in China since the early 21st century．The development and improvement of nanoflow-chromatography，heated dual ion source（DUIS） and other technologies are expected to improve the sensitivity of HRMS．The HRMS screening combined with triple quadrupole mass spectrometry confirmation technology，application and standardization of HRMS methods are the main directions for future research.关键词：high-resolution mass spectrometry（HRMS）;food;pesticide residues;high-throughput detection
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发布时间：2023-04-18 - 摘要：A key breakthrough in the development and commercialization of organic light-emitting diodes（OLEDs） is to use phosphorescent substances as light-emitting materials，which have a threefold increase in internal quantum efficiency compared to fluorescent materials．Among all phosphorescent materials，square planar platinum（Ⅱ） complexes have such advantages，namely，high structural rigidity，superior phosphorescent quantum yield，short decay lifetime and good chemical and thermal stability，which are important for realizing long-lifetime phosphorescent OLEDs．Meanwhile，platinum（Ⅱ） complexes could easily construct bidentate，tridentate or tetradentate ligands due to their planar coordination geometry，which may significantly affect the photophysical properties of platinum（Ⅱ） complexes．In addition，the employment of multiple Pt centers could further enhance the spin-orbit coupling and thus enhance phosphorescence emission．Based on the above considerations，the application of mononuclear and polynuclear platinum（Ⅱ） complexes containing bidentate，tridentate and tetradentate ligands in OLED luminescent materials is summarized in this paper，and the influence of ligand structure on device performance is discussed．Finally，the future development of platinum（Ⅱ） complex materials is also prospected.关键词：Pt（Ⅱ） complexes;phosphorescent material;aggregation-induced emission;organic light-emitting diode（OLED）
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发布时间：2023-04-18
Reviews
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