最新刊期
卷 45 ， 期 4 ， 2026
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摘要：This study employed near-infrared spectroscopy（NIR） combined with machine learning methods to discriminate Angelicae Sinensis Radix from its four similar herbs（Angelicae Pubescentis Radix，Chuanxiong Rhizoma，Atractylodis Macrocephalae Rhizoma，and Angelicae Dahuricae Radix）. A total of 191 samples collected from different regions were analyzed，and their NIR spectra were acquired. Principal component analysis（PCA） was first performed for unsupervised visualization. Subsequently，six machine learning models，including soft independent modeling of class analogy（SIMCA），partial least squares-discriminant analysis（PLS-DA），back propagation-artificial neural network（BP-ANN），random forest（RF），convolutional neural network（CNN），and extreme learning machine（ELM），were established. Model performance was evaluated using the confusion matrix，recall，precision，F1-score，and accuracy. The results indicated that the PCA score plot failed to effectively discriminate the five herbal medicines. Among the six machine learning models，the ELM model exhibited the best classification performance in terms of accuracy，recall，and F1-score，achieving 100% accuracy on the prediction set and outperforming the other models. Therefore，NIR spectroscopy combined with ELM can accurately discriminate Angelicae Sinensis Radix from its four similar herbs.关键词：Angelicae Sinensis Radix;discrimination analysis;near-infrared spectroscopy;chemical pattern recognition;machine learning153|81|0更新时间：2026-04-08
Special Topic for Original Works Competition of Scientific Instruments
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摘要：To systematically analyze the chemical composition differences of ‘Zhangbang’ processed Aconite（Linjiang Slices） before and after processing，this study screen and quantify the key differential quality markers，and elucidate the scientific basis of its processing. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry（UPLC-QTOF-MS/MS） combined with principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） was employed to screen and identify differential components. Furthermore，a simultaneous quantification method for multiple components was developed using ultra-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry（UPLC-QQQ-MS/MS） to determine the contents of the screened quality markers. PCA and OPLS-DA models（R²Y=0.990，Q²=0.988） clearly distinguished the samples before and after processing. A total of 43 differential components were screened，with 37 identified as diterpenoid alkaloids. Quantitative results demonstrated that the contents of aconitine，mesaconitine and hypaconitine，three diester-diterpenoid alkaloids，decreased significantly after processing（p<0.01），while the contents of benzoylmesaconine and benzoylaconine，two monoester-diterpenoid alkaloids，increased significantly（by 285.97% and 353.59%，respectively，p<0.01）. This study reveals that the Zhangbang processing method achieves‘toxicity reduction and efficacy enhancement’by promoting the conversion of diester-diterpenoid alkaloids to monoester-diterpenoid alkaloids. The established analytical methods and identified quality markers can provide a scientific basis for the quality control of Aconite（Linjiang Slices）.关键词：Aconite（Linjiang Slices）;component identification;chemical pattern recognition;UPLC-QQQ-MS/MS;Zhangbang processing;content determination127|186|0更新时间：2026-04-08 -
摘要：This study aims to characterize the chemical constituents of the Uygur medicine Operculina turpethum by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry（UPLC-Q/TOF-MS） integrated with multivariate statistical analysis，and to elucidate the chemical disparities among Operculina turpethum samples from different origins，thereby providing a chemotaxonomic reference for origin authentication and quality evaluation of Operculina turpethum. UPLC-Q/TOF-MS fingerprints were acquired for batches of Operculina turpethum collected from Pakistan，Guilin（China），and India. Unsupervised principal-component analysis（PCA） and supervised orthogonal partial least-squares discriminant analysis（OPLS-DA） were employed to reveal clustering trends and discriminant variables. Differential markers among the three origins were screened by combining variable importance in projection（VIP>1） from OPLS-DA with t-test（P<0.05）. The reliability of the selected markers was further validated by hierarchical clustering heat-map，relative content，and Pearson correlation analysis. A total of 83 chemical constituents were unambiguously identified in Operculina turpethum，and 14 differential markers were subsequently screened to discriminate the three commonly encountered geographical sources，among which picfeltarraenin IB and cynanchoside C exhibited pronounced inter-origin variations in abundance. The proposed strategy enables rapid and accurate geographical traceability of Operculina turpethum and furnishes robust chemical evidence for the origin authentication and quality assessment of this characteristic ethnic herbal medicine.关键词：Operculina turpethum;different origins;UPLC-Q/TOF-MS;multivariate statistical analysis;Differential components81|56|0更新时间：2026-04-08 -
摘要：The chemical constituents of Swertia mussotii Franch. were systematically identified and analyzed using UPLC-Q-TRAP-MS/MS technology. Separation was performed on a Shim-pack GIST HP C18 column（2.1 mm×100 mm，3 μm） with a gradient elution system consisting of 0.1% formic acid in water and acetonitrile. Mass spectrometry data were acquired in both positive and negative ion modes using EMS-IDA-EPI scanning to obtain primary and secondary mass spectra. Identification of chemical components was achieved by comparing with reference standards，reviewing literature，and interpreting mass spectrometry fragmentation patterns. A total of 88 compounds were identified from Swertia mussotii Franch.，including 48 xanthones，17 iridoid glycosides，19 flavonoids，1 disaccharide，2 phenylpropanoids，and 1 pentacyclic triterpenoid. Among these，25 compounds were reported for the first time in this plant，and 3 of them could not be reliably matched in existing literature and databases，suggesting that they may be novel compounds. This study first systematically summarized the mass spectrometric fragmentation patterns of the three major types of constituents in Swertia mussotii Franch. and successfully identified multiple chemical components. The findings provide experimental evidence and data supporting further research on the pharmacodynamic material basis and quality control of this medicinal herb.关键词：Swertia mussotii Franch.;UPLC-Q-TRAP-MS/MS;fragmentation pattern;xanthones;iridoid glycosides;flavonoids92|79|0更新时间：2026-04-08 -
摘要：Fluorescent brighteners（FBs），as industrial chemicals widely used in fields such as detergents，textiles，paper and plastics，have been identified as emerging contaminants that are frequently detected in various environmental matrices in recent years. However，the pollution status of FBs in agricultural soils in China remains unclear. To investigate the occurrence，regional distribution and composition characteristics of FBs in agricultural soils，a targeted analytical method based on ultrasonic-assisted solvent extraction and solid-phase extraction purification combined with high-performance liquid chromatography-triple quadrupole mass spectrometry（HPLC-MS/MS） was developed. This method was applied to screen，identify and quantitatively analyze 19 target FBs in agricultural soil samples collected from 18 provinces/municipalities across China. The results revealed widespread detection of FBs in agricultural soils. A total of 18 FBs in two major categories were identified，including 6 ionic FBs and 12 nonionic FBs. The total concentration ranged from 27.5 to 391 ng/g，with a median concentration of 160 ng/g. Among them，the detection frequency（DF） of 14 compounds was higher than 50%. A significant difference was observed in the spatial distribution of nonionic FBs，with concentrations being significantly higher in eastern China than in central China（p<0.05）. The compositional profiles of FBs were generally consistent across the eastern，central，and western regions，with ionic FBs being dominant，accounting for over 98% of the total FB concentration. Spearman correlation analysis indicated significant positive correlations（r=0.36-0.76，p<0.05） among most FBs within the same category，suggesting that these compounds may have a common pollution source or similar environmental fates in agricultural soils.关键词：agricultural soils;emerging contaminants;fluorescent brighteners;pollution characteristics;HPLC-MS/MS63|97|0更新时间：2026-04-08 -
摘要：Organophosphate esters（OPEs） are a class of important novel organic pollutants in the atmosphere. However，research on the effects of environmental factors on atmospheric OPE concentrations and their source differences between urban and suburban areas remains limited. In this research，atmospheric particles were collected in urban and suburban areas of Guangzhou. Differences in pollution levels and compositional profiles of OPEs between urban and suburban areas were revealed，and the environmental factors influencing their atmospheric concentrations were also investigated. In addition，the sources of OPEs in urban and suburban areas were apportioned using the positive matrix factorization（PMF） model to elucidate their differences. The results showed that chlorinated and aryl OPEs（Cl-OPEs and Aryl-OPEs） exhibited higher pollution levels in suburban areas than in urban areas，whereas alkyl-OPEs（Alkyl-OPEs） showed relatively small urban-suburban differences. Most OPE concentrations were positively correlated with NO2 and CO concentrations，indicating that vehicle exhaust and industrial processes are important emission sources. Some OPEs were positively correlated with O3 concentrations，suggesting that these compounds may be partly formed through atmospheric transformation of phosphites. Wind speed was identified as the most critical factor affecting atmospheric OPE concentrations in meteorological factors. Ridge regression analysis revealed that vehicle exhaust and industrial emissions were the key factors driving the differences in the compositional profiles of Alkyl-OPEs and Cl-OPEs between urban and suburban areas. The PMF model apportioned OPEs in both study areas into five sources. Emissions associated with plastic production were the dominant source in suburban areas，whereas vehicle exhaust was the primary source of OPEs in the urban atmosphere. Risk assessment showed that the health risk from inhalation exposure to OPEs in urban and suburban areas of Guangzhou is low.关键词：organophosphate esters;atmospheric particles;source apportionment;influence of environmental factors78|113|0更新时间：2026-04-08 -
摘要：To analyze the differences in chromone components between wild and cultivated Saposhnikovia divaricata，providing a basis for its quality control and sustainable resource utilization. The contents of prim-O-glucosylcimifugin，5-O-methylvisamminol，cimifugin，and hamaudol glucoside in 33 batches of samples were determined by HPLC. The differential components between the two types of samples were analyzed using a combination of the K-nearest neighbors（KNN） algorithm and principal component analysis（PCA）. A bionic electronic nose was used to collect odor information from the samples，and KNN combined with PCA was employed to analyze their odor differences. Correlation analysis was then conducted between the sensor response values and the chromone content. The results indicated a significant difference in the content of chromone compounds between wild and cultivated S. divaricata，with hamaudol glucoside contributing the highest discrimination rate. Electronic nose analysis indicated that the overall odor fingerprints of wild and cultivated S. divaricata were distinguishable. The response patterns of sensors S10 and S13 contributed most to distinguish the two sample types，with wild S. divaricata generally exhibiting stronger overall responses across the sensor array. Some sensors were significantly correlated with chromone components，in which sensors S4 and S5 showed a significant positive correlation with hamaudol glucoside，while sensor S10 showed a negative correlation with cimifugin. Therefore，the combined analytical approach of electronic nose and HPLC can effectively distinguish between wild and cultivated S. divaricata，providing a novel method for quality evaluation of this medicinal material.关键词：wild and cultivated Saposhnikovia divaricata;bionic electronic nose;HPLC;K-nearest neighbors（KNN）;principal component analysis（PCA）36|69|0更新时间：2026-04-08 -
摘要：Mass spectrometry imaging（MSI） is a valuable molecular imaging technique with high spatial resolution，enabling the in-situ detection of both endogenous and exogenous compounds in biological tissues. However，under high spatial resolution conditions，limitations in detection sensitivity often lead to extensive signal missing in MSI data，which significantly compromises the accuracy and depth of downstream analyses. Traditional approaches to enhance sensitivity through hardware upgrades are often costly and time-consuming，hindering broad adoption. To address this，we propose a missing value imputation method based on the artificial intelligence，which learns the complex distribution characteristics of MSI data in a data-driven manner to achieve high-quality reconstruction of missing signals. Experimental results on both mouse kidney MALDI-MSI and human colon cancer DESI-MSI datasets demonstrate that the proposed method outperforms conventional imputation techniques in terms of visual consistency and quantitative error，while also exhibiting good cross-platform adaptability. This study provides an efficient and low-cost solution for improving MSI data quality and detection sensitivity，holding significant potential for advancing subsequent analyses.关键词：mass spectrometry imaging;sensitivity;missing value imputation;artificial intelligence101|188|0更新时间：2026-04-08 -
摘要：This study focuses on maize and addresses the problem of insufficient accuracy in nitrogen content monitoring under cold-region cultivation conditions. After comparing multiple preprocessing methods，the combined use of discrete wavelet transform（DWT） and standard normal variate（SNV） was adopted as the preprocessing approach，and several feature selection algorithms including competitive adaptive reweighted sampling（CARS），uninformative variable elimination（UVE），successive projections algorithm（SPA），genetic algorithm（GA），and genetic algorithm-successive projections algorithm（GA-SPA） were systematically compared. Combined with multiple regression models such as partial least squares regression（PLSR），support vector regression（SVR），kernel extreme learning machine（KELM），deep extreme learning machine（DELM），extreme gradient boosting（XGBoost），and one-dimensional convolutional neural network（1D-CNN），the hyperspectral inversion performance for maize nitrogen content was comprehensively evaluated. The results showed that full-band modeling achieved high fitting accuracy in the training set but exhibited low predictive accuracy in the test set，indicating a clear overfitting issue. After introducing feature selection，model performance was significantly improved，with the GA-SPA algorithm performing best in feature extraction and redundancy suppression. The combination of GA-SPA and the DELM model achieved the highest prediction accuracy，with a test-set R² of 0.811 1 and RMSE of 0.493 0，outperforming other combinations. Moreover，GA-SPA also maintained high prediction stability in PLSR，KELM，and SVR models. The findings demonstrate that the DELM modeling framework based on DWT+SNV preprocessing and GA-SPA feature optimization can effectively enhance the accuracy and generalization ability of maize nitrogen content estimation，providing reliable technical support for nutrient monitoring and precision fertilization in cold-region maize cultivation.关键词：maize;nitrogen content;hyperspectral technology;GA-SPA;DELM61|148|0更新时间：2026-04-08 -
摘要：The targeted extract of cathinone alkaloids from dried khat was analyzed using HPLC-Q-TOF MS. A ZORBAX Eclipse Plus C18 column（3.0 mm×100 mm×1.8 μm） was employed with a gradient elution of acetonitrile and 0.1% formic acid in water as the mobile phases. After the first-generation mass spectrometry data were collected in automatic ion acquisition mode（Auto MS/MS），an ion exclusion list was generated using the MS Convert GUI and IE-Omics software. The second-generation mass spectrometry data were then collected after importing the exclusion list，and this operation was repeated to obtain the third-generation dataset. The data were pre-processed using MS-DIAL，and the feature-based molecular networking and network annotation propagation（FBMN-NAP） workflow combined with MS-FINDER was applied for data visualization，compound library matching，and structural prediction. A total of sixteen suspected cathinone alkaloids were detected，including three pairs of chiral isomers. The in-source decay combined with iterative MS/MS acquisition was employed to analyze the mass spectrometric dissociation pathways and to validate the results of library matching and structural prediction. The joint identification by MS-FINDER and NAP predicted the chemical structures of four compounds，while NAP alone identified two compounds. For the remaining components without confident matches or predictions，eight structures were inferred by interpreting the fragment ion dissociation patterns and structural annotations in the matched spectra. In total，the chemical structures of fourteen compounds were elucidated，while the other two，exhibiting significantly different dissociation behaviors，could not be deduced. This study employed high-resolution HPLC-Q-TOF MS combined with iterative MS acquisition and feature-based molecular networking analysis to systematically characterize the cathinone alkaloid composition of dried Catha edulis（Khat）. A total of sixteen related compounds were identified，and the chemical structures of fourteen were elucidated or tentatively proposed. The results provide systematic experimental evidence for the chemical profile of the khat metabolome.关键词：Catha edulis;cathinone alkaloids;targeted metabolomics;HPLC-Q-TOF MS;feature-based molecular networking（FBMN）;MS-FINDER54|76|0更新时间：2026-04-08 -
Ratiometric Photoelectrochemical Microsensor for
In Vivo Detection of Hypochlorous Acid in the Brain 增强出版 AI导读
摘要：As a key reactive oxygen species（ROS） in neuroinflammatory processes，real-time monitoring of hypochlorous acid（HClO） concentration changes in the living brain is of great significance for revealing the pathogenic mechanisms of brain diseases. However，due to the complexity of the in vivo environment，the development of in situ analytical tools with both high selectivity and accuracy remain challenging. In this study，a ratiometric photoelectrochemical（PEC） microsensor based on a competitive absorption mechanism was constructed. The sensing interface was fabricated by co-modifying a specific small-molecule probe and CdTe quantum dots（QDs） onto a fiber-optic microelectrode. Utilizing HClO-triggered changes in the absorption spectrum of the probe to regulate the competitive absorption relationship，ratiometric PEC detection of HClO was achieved. This microsensor not only exhibits high selectivity for HClO but also its ratiometric signal can effectively overcome interferences in the complex in vivo environment. Ultimately，the sensor was successfully applied for in situ real-time monitoring of HClO in the brains of living mice，and preliminary revealed a direct correlation between PM2.5 exposure and elevated HClO levels in the brain. This work provides a reliable tool for the in vivo monitoring of HClO.关键词：photoelectrochemical sensing;competitive absorption;small-molecule probe;hypochlorous acid;ratiometric signal;living brain tissue144|182|0更新时间：2026-04-08 -
摘要：Silver nanoparticles（AgNPs） were biosynthesized via a one-step method at room temperature within 10 min，using green tea extracts as the reducing and protecting agents，with silver nitrate as the precursor. In the presence of AgNPs，ascorbic acid（AA） reduced Ag+ to Ag0，which deposited onto the surface of AgNPs，causing an increase in the particle size of AgNPs. This growth induced corresponding changes in the absorbance at 416 nm，the average grayscale value of Tyndall effect，and the color intensity. Thus，a novel scattering-colorimetric dual-mode sensor for AA detection was developed by integrating Tyndall effect grayscale analysis with smartphone RGB colorimetry. The detection limits for these two modes were 0.018 and 0.34 µg/mL，respectively，superior to that of the conventional UV-Vis spectrophotometer（0.66 µg/mL）. The method was applied to determine AA in commercial beverages and vitamin C tablets with satisfactory spiked recoveries. The results obtained from the two modes showed good agreement，which significantly enhanced the reliability of the detection results. Notably，the proposed dual-mode system required no expensive instruments，exhibited high accessibility for popularization，and provided a promising approach for on-site，real-time，rapid analysis of AA in food and pharmaceutical samples.关键词：silver nanoparticles;Tyndall effect;smartphone colorimetry;ascorbic acid;dual-mode detection60|86|0更新时间：2026-04-08 -
Research on Identification and Origin Traceability of Metal Elements in Pistachios and Almonds 增强出版 AI导读
摘要：The concentrations of 58 metal elements in 70 nut samples were determined to establish an origin traceability method for pistachios and almonds. The samples were digested using a super microwave digestion system and analyzed for elemental content via inductively coupled plasma mass spectrometry （ICP-MS） and inductively coupled plasma optical emission spectrometry （ICP-OES）. Multivariate statistical techniques，including principal component analysis （PCA），partial least squares-discriminant analysis （PLS-DA），and orthogonal partial least squares-discriminant analysis （OPLS-DA），were employed to elucidate the characteristic distribution patterns of elements in nuts from different geographical origins and to construct a discriminant model for origin identification. Blind validation results demonstrated that the OPLS-DA model achieved high accuracy in determining the origin of unknown samples，with identification accuracies of 90% for U.S. almonds，and 100% for U.S. pistachios，Iranian pistachios and Australian almonds. This research provides a reliable technical basis for the accurate origin authentication and trade regulation of nut products at ports.关键词：nuts;metal elements;origin traceability;statistical techniques;discriminant model62|88|0更新时间：2026-04-08
Scientific Papers
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摘要：A method based on hydrophilic-lipophilic balance（HLB） solid-phase extraction（SPE） coupled with liquid chromatography-tandem mass spectrometry（LC-MS/MS） was developed for simultaneous determination of five p-phenylenediamines（PPDs） and their corresponding quinone derivatives（PPD-Qs） in human urine samples. The types of SPE cartridges and SPE conditions were optimized. The HLB cartridges were first sequentially conditioned with 3 mL of methanol and 3 mL of water. After being loaded with 1 mL of the diluted urine（urine/water，1∶2，volume ratio） at a flowrate of 0.5 mL/min，the cartridges were washed with 2 mL of methanol/water（5∶5，volume ratio） and eluted with 3 mL of acetonitrile. The collected eluates were centrifuged and filtered prior to LC-MS/MS analysis. Using 6PPD-Q-D5 as an internal standard，the method exhibited a wide linear range of 0.01-20 ng/mL with linear correlation coefficients not less than 0.999 2. The limits of detection（LODs） and limits of quantification（LOQs） were 0.003-0.02 ng/mL and 0.01-0.07 ng/mL，respectively. The recoveries at three spiked levels were found to be 80.1%-108%，with the intra-day and inter-day precisions ranging from 0.70% to 9.0% and from 1.1% to 10%，respectively. The validated method was applied to the simultaneous determination of PPDs and PPD-Qs in urine samples from 30 college student volunteers. The total detection frequencies varied from 10.0% to 60.0% with total concentrations of <LOD-4.62 ng/mL. The method with high sensitivity and accuracy is suitable for the simultaneous determination of PPDs and PPD-Qs in human urine samples.关键词：p-phenylenediamine antioxidants;p-phenylenediamine quinone derivatives;solid-phase extraction;urine;liquid chromatography-tandem mass spectrometry80|93|0更新时间：2026-04-08 -
摘要：Herein，a novel analytical method based on miniaturized matrix solid-phase dispersion （m-MSPD） combined with gas chromatography-mass spectrometry（GC-MS） was developed for the determination of 11 organophosphate flame retardants（OPFRs） in fish samples. Response surface methodology was performed for the systematic optimization of key extraction parameters，including adsorbent，eluent，and vortex time. The optimal extraction conditions were confirmed as follows：300 mg of PSA adsorbent，4 mL of acetone as eluent，and a vortex time for 2 min. The method exhibited excellent linearity over the concentration range of 5-500 μg·L-1 （r2>0.998）. The limits of detection（LODs） and quantification（LOQs） were in the ranges of 0.13-5.33 ng·g-1 and 0.44-17.78 ng·g-1，respectively. The spiked recoveries ranged from 68.3% to 116%，with relative standard deviations（RSDs） of 0.020% to 8.7%. The method was successfully applied for the detection of OPFRs in actual fish samples，including wild and cultured crucian carp and bighead carp. Owing to its advantages of low organic solvent consumption，fast analysis speed，and minimal matrix interference，it is suitable for the efficient and simultaneous analysis of multiple OPFRs in aquatic products.关键词：fish samples;miniaturized matrix solid-phase dispersion extraction（MSPD）;response surface methodology;organophosphate flame retardants（OPFRs）;gas chromatography-mass spectrometry（GC-MS）52|68|0更新时间：2026-04-08 -
摘要：To address the critical bottlenecks of low resolution and poor analytical efficiency associated with co-eluting organic acid components in the complex matrix of tobacco flavoring liquids，a high-efficiency analysis method based on ion-exclusion chromatography（IEC） was developed. A comparative investigation into the separation mechanisms of anion exchange and ion exclusion revealed that：By leveraging the unique synergistic effect of Donnan exclusion and hydrophobic adsorption on the ICE-AS6 column，combined with a heptafluorobutyric acid elution system，the method effectively overcame the limitation of low resolution（R<1.0） between lactic and acetic acids inherent to conventional ion chromatography，achieving baseline separation（R≥2.14） for citric acid，malic acid，lactic acid，and acetic acid. The method exhibited good linearity within the range of 0.50-50.0 mg/L，with limits of detection（LOD） of 0.13-0.15 mg/L and limits of quantification（LOQ） of 0.45-0.51 mg/L，while precision and spike recovery rates fully met analytical requirements. Chemometric analysis of 102 typical tobacco flavoring liquid samples revealed significant clustering characteristics，classifying samples into a high-malic-acid type（6.9%），a high-lactic/acetic-acid type（20.6%），and a low-acid universal type（72.5%），which correlated highly with the sensory functional positioning of the tobacco flavoring liquids. This study not only resolves the co-elution interference of organic acids in complex tobacco flavoring liquids matrices but also provides data support for quality traceability and precise control in cigarette flavoring processes.关键词：Ion-exclusion chromatography;tobacco flavoring liquids;organic acids;cluster analysis53|89|0更新时间：2026-04-08 -
摘要：Qualitative and quantitative analysis of monoglycerides in liquid milk was conducted using NMR pulse length-based concentration determination（PULCON） combined with multiple NMR techniques. Selective one-dimensional total correlation spectroscopy（1D-TOCSY） and two-dimensional NMR were employed to accurately assign the 1H NMR signals of α-monoglycerides and β-monoglycerides in liquid milk. Based on the qualitative results，the absolute contents of the two monoglyceride isomers were determined using the PULCON method，with 2 mmol/L maleic acid in D2O as the external standard and the signals at δ3.93 and δ3.82 as the quantitative peaks for α-monoglyceride and β-monoglyceride，respectively. The limits of detection for α-monoglyceride and β-monoglyceride were 0.17 mmol/L and 0.02 mmol/L，while the limits of quantification were 0.51 mmol/L and 0.06 mmol/L，respectively. This method is rapid，requires only a small sample amount，and does not need internal reference standards，making it suitable for the rapid determination of both isomeric forms and total monoglyceride content in liquid milk.关键词：proton nuclear magnetic resonance（1H NMR）;quantitative nuclear magnetic resonance（qNMR）;monoglyceride;pulse length based concentration determination（PULCON）;liquid milk44|56|0更新时间：2026-04-08 -
摘要：This study introduces a dual element stable isotope analysis approach to establish compound-specific carbon and chlorine isotope analysis methods for tris（2-chloroethyl） phosphate（TCEP），aiming to elucidate its anaerobic microbial transformation mechanism. By optimizing the extraction and purification procedures，high recovery（96.3%） and low matrix interference were achieved，and the δ13C values of TCEP in pretreated samples measured by gas chromatography-isotope ratio mass spectrometry（GC-IRMS） differed from those of the reference standard by no more than 0.5‰. A compound-specific chlorine stable isotope analysis method for TCEP was developed using gas chromatography-quadrupole mass spectrometry（GC-qMS）. Through optimization of analytical conditions，optimal signal-to-noise ratios were obtained at TCEP concentrations of 5 mg/L，a dwell time of 50 ms，and an ion source voltage of 300 V，with standard deviations of chlorine isotope ratios ranging from 0.000 11 to 0.000 28. Application of the established method to an anaerobic microbial transformation system of TCEP revealed significant carbon and chlorine isotope fractionation，indicating that C—Cl bond cleavage is the rate-limiting step in the transformation process. This method provides a robust technical foundation for in-depth investigation of the transformation mechanisms and environmental behavior of chlorinated organophosphate esters.关键词：organophosphate flame retardants;stable carbon isotope;stable chlorine isotope;dual element isotope analysis;reaction mechanism67|41|0更新时间：2026-04-08 -
摘要：The research aims to establish a comprehensive evaluation method for quality grading of vine tea（Ampelopsis grossedentata） based on the entropy-weighted TOPSIS model. The corresponding quality standards were developed by combining the major bioactive components and taste-related compounds in vine tea and sensory evaluation. Significant differences were observed in the contents of dihydromyricetin and its isomers，myricetin，myricitrin，and pinosylvin，as well as in sensory scores across samples. Using the entropy weight method，the weights of each evaluation indicator were calculated. Grey relational analysis was further applied to identify key factors influencing vine tea quality. The vine tea samples were classified into four quality grades—premium，grade Ⅰ，grade Ⅱ and grade Ⅲ—based on their relative closeness（Ci） and ranking percentages，accounting for approximately 5%，35%，35% and 25% of total samples，respectively. The proposed quality evaluation system integrates the active constituents，taste-related compounds，and sensory characteristics of vine tea infusion，enabling a multidimensional and quantitative assessment of vine tea quality.关键词：vine tea;bioactive compounds;sensory evaluation;TOPSIS;quality grading117|320|0更新时间：2026-04-08 -
摘要：To explore the effects of different synbiotic combinations on B vitamin levels and the quality of functional fermented milk，seven probiotic strains［Bifidobacterium animalis subsp. lactis（BB12，BB04，BB420），Lactobacillus rhamnosus（LGG1，LGG2），and Lactobacillus paracasei（Lpc1，Lpc2）］were selected and combined with three oligosaccharides ［fructo-oligosaccharides（FOS），isomalto-oligosaccharides（IMO），and 2'-fucosyllactose（2'-FL）］ were selected to construct synbiotic systems and prepare fermented milk samples in this study. High performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS） was utilized for the quantitative determination of key B vitamins in the fermented milk，including riboflavin，nicotinic acid，nicotinamide，pantothenic acid，pyridoxal phosphate，biotin，and et al. Quality assessment was performed by integrating the analysis of sensory properties，viscosity，pH value，and acidity indices. The results demonstrated that different synbiotic combinations exerted combination-specific regulatory effects on the B vitamin profiles in fermented milk. Notably，the co-fermentation of oligosaccharides with Bifidobacterium strains exhibited a significantly greater enhancement in the contents of various B vitamins compared to the combinations involving Lactobacillus strains. Furthermore，synbiotic could differentially modulate the viscosity of fermented milk while reducing its pH value and acidity. At the sensory level，the synbiotic fermented milk formulated with Lactobacillus strains，particularly Lactobacillus rhamnosus，achieved the optimal quality and favorable stability. This study provides a scientific basis for the development of B vitamin-enriched functional fermented milk products.关键词：functional fermented milk;high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）;B vitamins;synbiotic41|171|0更新时间：2026-04-08 -
摘要：An analytical method using QuEChERS/isotope internal standard-ultra performance liquid chromatography-tandem mass spectrometry was established to determine 11 doping agents in soft capsule-type Chinese patent medicines. Optimized QuEChERS pretreatment was adopted：samples were extracted with an acetonitrile-water system，purified by C18 dispersive solid-phase extraction，and reconstituted sequentially with 200 μL initial mobile phase and acetonitrile. Separation was performed on an Agilent Eclipse Plus C18 column（4.6 mm×100 mm，1.8 μm） with gradient elution using 10 mmol/L ammonium formate-0.05% formic acid aqueous solution and acetonitrile. Detection was conducted in positive ion mode with multiple reaction monitoring（MRM）； qualification relied on retention time and ion abundance ratio，and quantification on the isotope internal standard method. Results showed that all 11 doping agents had good linearity in 0.1-1 000 ng/mL（r²>0.998）. The limits of detection was 0.04-25.0 ng/g，and the limits of quantitation was 0.2-80.0 ng/g. Average recoveries of the 11 doping agents in blank soft capsules at three spiking levels were 60.2%-119%，with relative standard deviations（RSD，n=6） of 1.2%-11%. This method was applied to detect 11 batches of soft capsule-type Chinese medicine samples，with the target analytes identified in 5 batches. This method，with simple pretreatment，high accuracy and good reproducibility，is suitable for rapid screening and quantitative analysis of multiple doping agents in soft capsule-type Chinese patent medicines.关键词：QuEChERS;isotope internal standard;ultra performance liquid chromatography-tandem mass spectrometry;doping agents;soft capsules;Chinese patent medicine97|48|0更新时间：2026-04-08 -
摘要：Based on the development and application of carbon quantum dot technology，this study prepared nitrogen and chlorine co-doped carbon quantum dots（N，Cl-CDs）via the hydrothermal method，using o-phenylenediamine and neutral red as raw materials. The morphology and optical properties of N，Cl-CDs were characterized by techniques including transmission electron microscopy，X-ray photoelectron spectroscopy，ultraviolet-visible spectroscopy，and fluorescence spectroscopy. The detection approaches of six tetracycline antibiotics were established including tetracycline，chlortetracycline，oxytetracycline，doxycycline，tigecycline，and metacycline，based on the fluorescence quenching phenomenon induced by the inner filter effect（IFE） between N，Cl-CDs and tetracycline antibiotics. The linear ranges were from 0.05 to 80.0 μg/mL，with the limits of detection（LODs） for all six antibiotics of 0.01 μg/mL（S/N=3） and the limits of quantification（LOQs） of 0.05 μg/mL（S/N=10），respectively. For environmental water samples，the average spiked recoveries of the six tetracycline antibiotics were ranged from 99.6% to 103%，while the average relative standard deviations（RSDs） were not more than 2.0%. For urine samples，the average spiked recoveries were ranged from 98.9% to 103%，with the average RSDs not more than 2.2%. This material boasts the advantages of a simple preparation process and low cost，as well as excellent selectivity，high anti-interference capacity and superior detection sensitivity in complex matrices，and can be employed for the rapid and accurate detection of tetracycline antibiotics in various matrices.关键词：nitrogen and chlorine co-doped;carbon quantum dots;tetracycline;environmental water;urine74|146|0更新时间：2026-04-08 -
摘要：Due to its addictive and toxic properties，morphine demands rapid and accurate detection. Traditional liquid chromatography-mass spectrometry is difficult to use for on-site analysis，while electrochemical sensing has become one of the preferred techniques owing to its low cost and high sensitivity. Two-dimensional Ti3C2TX MXene exhibits excellent electrical conductivity and large specific surface area，but tends to aggregate. Multi-walled carbon nanotubes（MWCNTs） can inhibit this aggregation，leading to a synergistic enhancement between the two materials. In this study，Ti3C2TX was prepared by etching Ti3AlC2 with HCl/LiF，and then ultrasonically composited with acidified MWCNTs. The glassy carbon electrode（GCE） was modified via drop-casting to construct the MWCNTs/Ti3C2TX/GCE sensor. The material was characterized using X-ray diffraction（XRD），scanning electron microscopy（SEM），and transmission electron microscopy（TEM），while its performance was evaluated via cyclic voltammetry（CV） and differential pulse voltammetry（DPV）. The results showed that MWCNTs were successfully intercalated into the layers of Ti3C2TX，effectively inhibiting its aggregation. The electrochemically active surface area of the composite electrode was 10 times that of the bare GCE. After optimization，the sensor displayed a linear response toward morphine in the range of 1.0 × 10-6-1.0 × 10-2 mol/L，with a linear equation of Iₚₐ=6.149 8 logC + 69.855（r²=0.979 0） and a limit of detection as low as 0.263 μmol/L. The sensor also showed excellent anti-interference ability，repeatability，and stability. When applied to the detection of morphine in human sweat，the spiked recoveries ranged from 92.3% to 96.8%，with relative standard deviations（RSDs） all less than 5.0%. This sensor overcomes the stacking problem of Ti3C2TX and shows excellent performance，providing a feasible scheme for the rapid on-site detection of morphine and a reference for the development of MXene-based sensors.关键词：multi-walled carbon nanotubes;MXene;Enzyme-free electrochemical sensor;morphine;electrochemical detection67|131|0更新时间：2026-04-08 -
摘要：In this study，a fluorescent europium-based metal-organic framework（Eu-MOF） probe is fabricated for SDZ detection via a fluorescence quenching mechanism. To achieve optimal analytical performance，key parameters including excitation wavelength，mass concentration of the Eu-MOF probe，pH of the solution system，and incubation time are optimized. Under optimal conditions，the proposed method exhibits rapid response（30 s），a good linear range（0-14 µg/mL），and a low detection limit（0.035 µg/mL），along with excellent recognition selectivity. Mechanism analysis reveals that the selective detection of SDZ by the Eu-MOF probe primarily relies on photoinduced electron transfer（PET） and the inner filter effect. Furthermore，the probe demonstrates satisfactory accuracy in real water sample analysis，with good recovery（86.5%-110%） and low relative standard deviation（<10%）. These results highlight the promising potential of the Eu-MOF probe for rapid detection of trace SDZ.关键词：sulfadiazine;environment analysis;metal-organic framework;fluorescence probe54|101|0更新时间：2026-04-08 -
摘要：The abuse of new benzodiazepines may lead to dependence，withdrawal reactions，and various health hazards. Saliva collection is not limited by location，making it suitable for various application scenarios such as drug-impaired driving sites. To evaluate the abuse of new benzodiazepines，this paper proposes a method for the determination of 18 new benzodiazepines in saliva based on ultra-high performance liquid chromatography-quadrupole/orbitrap mass spectrometry（UPLC-Q/Orbitrap HRMS）. The chromatographic conditions，mass spectrometry parameters and pretreatment methods were optimized，and the attribution of mass spectral characteristic peaks was analyzed. Saliva samples were treated using an acetonitrile protein precipitation method and quantified by an internal standard method under parallel reaction monitoring mode. The experimental results showed that 18 new benzodiazepines were detected within 8 min. The calibration curves for the 18 NBZs exhibited good linearity in their respective mass concentration ranges，with correlation coefficients r2≥0.999 0. The limits of detection ranged from 0.009 to 0.36 ng/mL，and the limits of quantitation ranged from 0.03 to 1.20 ng/mL. At three spiked levels of 2，10 and 50 ng/mL，the recoveries of 18 new benzodiazepines ranged from 89.2% to 104%. The intra-day precisions ranged from 1.1% to 8.7%，and the inter-day precisions ranged from 1.6% to 9.8%. This method offers the advantages of high speed and high sensitivity. It can be used for qualitative and quantitative analysis of 18 new benzodiazepines in saliva samples to meet relevant identification requirements，providing a reliable reference for the detection of such substances in saliva.关键词：ultra-high performance liquid chromatography-quadrupole/orbitrap mass spectrometry;saliva;new benzodiazepines;protein precipitation method57|84|0更新时间：2026-04-08
Experimental Techniques and Methods
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摘要：Spectral imaging technology integrates spectral analysis with spatial imaging capabilities，enabling comprehensive multidimensional characterization of the chemical composition and morphological distribution of forensic evidence. It has emerged as a cutting-edge optical force driving advancements in forensic science evidence examination. Leveraging advantages such as speed，non-invasiveness，and minimal pretreatment requirements，this technology plays a pivotal role in the visualization，identification，and classification of diverse field evidence. This paper systematically reviews the fundamental principles and latest research advances of mainstream spectral imaging technologies—including hyperspectral imaging，Raman imaging，and terahertz time-domain imaging—based on bibliometric analysis. It focuses on exploring their typical application scenarios and effectiveness in examining biological evidence，trace evidence，and document analysis. Furthermore，the paper analyzes critical challenges in practical application，including sensitivity limitations，lack of standardized protocols，and environmental interference. It also outlines future development trends—such as multimodal integration，intelligent analysis，and portable device development—to provide a technical roadmap for establishing a new generation of spectroscopic precision forensic evidence examination systems.关键词：spectral imaging technology;forensic science;optical non-destructive testing;evidence examination;spectral analysis107|152|0更新时间：2026-04-08
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