MICROCHEMICAL JOURNAL
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2026
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IF 5.1
Qing-nan Chen,Yun-e Bai,Yao Ma,Rui Liao,Lu-lu Wang,Shuang Hu,Jian- ping Gao
Latex-bearing plants have gained global attention, but few studies have been reported on Codonopsis pilosula (Franch.) Nannf.( C. pilosula ) latex. In this research, we established a UHPLC-MS/MS method to investigate the constituents in C. pilosula latex. Analysis revealed that the latex of C. pilosula contains alkaloids, terpenoids, and fatty acids, with fatty acids being one of the primary metabolites distinguishing the latex from above-ground (DS) and below-ground (DX) parts of C. pilosula. To evaluate the quality of C. pilosula latex, an approach of dispersive liquid-liquid microextraction with solidification of the floating organic drop (DLLME-SFO) methodology was developed to quantitatively analyze the contents of three fatty acids (palmitic, linoleic, and stearic) in the latex of C. pilosula . The ideal extraction conditions involve injecting 20 μL of dodecanol extractant into a 5 mL 10% NaCl solution at pH 3.0, followed by 20 min at 700 rpm. The three components mentioned above have enrichment coefficients ranging from 48 to 50. The quantification limits were between 0.23 and 0.25 μg/mL, and three components demonstrated good linearity in their respective linear ranges (R 2 > 0.995). The satisfied precision and recovery rates were 1.26 to 8.05% and 92.38 to 101.53%, respectively. By quantitatively analyzing the three fatty acid contents in the latex of C. pilosula , the results showed that palmitic and linoleic acids were able to successfully distinguish the latex of C. pilosula from different parts, which laid the foundation for the quality evaluation of C. pilosula , and provided a reference for the utilization of C. pilosula , a medicinal food source.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2026
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IF 2.4
Xinjun Zhou,Jing Jiang,Xiaopeng Chen,Chenghong Wu,Linlin Wang,Xiaojie Wei,Liyuan Tan,Jiezhen Liang
Isothermal vapor–liquid equilibrium data were measured for the binary systems related to α-pinene + myrcene, α-pinene + β-caryophyllene, and myrcene + β-caryophyllene using static headspace gas chromatography at 313.2, 323.2, and 333.2 K. The experimental data were correlated with the nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) models to obtain the binary interaction parameters. The small deviations demonstrated great agreement between the models and the experimental data. Moreover, the NRTL model showed marginally superior predictive accuracy in data association compared with the UNIQUAC model. The three binary systems exhibited simple phase behaviors with no azeotrope formation. In addition, the molecular surface charge profile and the binary energies of these systems were used to validate the strength of the σ-profile and to elucidate the role of intermolecular interactions in vapor–liquid equilibrium.
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Foods
·
2026
·Vol. 15
·期 16
·2894
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IF 6
Chengjiang Wei,Weiwei Wu,Zhechen Han,Peng Zhang,Chenglong Li,Siqing Du,Qi Lin,Fuming Lin,Weijiang Sun
Wuyi rock tea (WRT) processed from dew-soaked leaves is often characterized by a pronounced grassy off-odor defect. However, the key odor-active compounds and their potential underlying mechanisms remain unclear. In this study, quantitative descriptive sensory analysis, GC–MS, GC–O, molecular docking, and aroma addition tests were used to systematically elucidate the chemical basis and potential perceptual mechanisms of the key grassy off-odor in WRT processed from dew-soaked leaves. The results showed that 16 volatile compounds were significantly associated with dew, among which (E,E)-2,4-heptadienal, octanal, hexanal, and heptanal were identified as the major odor-active compounds responsible for the grassy off-odor. The accumulation of these aldehydes may be associated with lipid peroxidation under the influence of dew. Aroma addition and omission tests confirmed that (E,E)-2,4-heptadienal contributed significantly to grassy off-odor formation and that additive effects existed among the four compounds. Molecular docking predicted that the four key odor-active compounds interacted with human olfactory receptors, including OR1A1 and OR10J5, through hydrogen bonds and hydrophobic interactions, thereby affecting grassy off-odor perception, with predicted binding energies below −4.7 kcal/mol. This study elucidated the effects of dew on the formation of the characteristic aroma of WRT and provides a scientific basis for tea quality regulation and processing improvement.
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Food Chemistry-X
·
2025
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IF 8.2
Xianling Lan,Xiaoqin Pan,Jiawei Luo,Shan Xiao,Yanxue Cai,Jihui Wang
Skipjack tuna oil that is rich in polyunsaturated fatty acids, is prone to developing fishy odors under high-temperature or oxidative conditions. This study investigated the effects of four treatments—low-temperature thermal, low-concentration oxidation, high-concentration oxidation, and high-temperature thermal—on oxidation degree, volatile compounds, fatty acids, and sensory characteristics. GC–MS identified five key volatile compounds: hexadecanoic acid, ethyl ester; octadecanoic acid, ethyl ester; ethyl oleate; ethyl 9-hexadecenoate; and ethyl 6,9,12,15-octadecatetraenoate. Oxidation induction significantly increased peroxide value and acid value, primarily by generating aldehydes (e.g., hexanal, heptanal), which intensified fishy odors. In contrast, by GC-IMS analysis, higher concentrations of fishy odor markers, 1-octen-3-ol (0.48 ± 0.05 %), 2-ethylfuran-D (0.75 ± 0.01 %), and (E)-2-heptenal-D (0.08 ± 0 %) were found in the high temperature thermal group, showing a more pronounced impact of thermal induction on flavor dynamics than oxidative pathways. These findings elucidate the dual roles of oxidation and thermal degradation in fishy odor formation.
研究领域:
食品科学
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化学
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JOURNAL OF CHROMATOGRAPHY A
·
2025
·
IF 4
Wenhui Lu,Jing Chen,Liangliang Zhang,Zixuan Nie
Determining the temporal evolution of inks remains a critical challenge in forensic document analysis. The temporal evolution stages classification and aging time prediction of gel-pen ink were investigated by integrating gas chromatography-ion mobility spectrometry (GC-IMS) with machine learning algorithms. Ink-specific volatile markers were correlated with aging mechanisms through kinetic modeling and heatmap analysis. Three distinct temporal evolution stages were categorized into the rapid evaporation stage, slow-release stage, and chemical stabilization stage through multivariate analysis of volatiles. Furthermore, six tree-based machine learning algorithms were systematically evaluated, with the Categorical Boosting (CatBoost) model achieving superior performance (accuracy=100 %) in classifying five detailed aging stages of gel-pen ink. The decision tree regression model demonstrated high temporal prediction accuracy (test R²=0.954) through interpretable feature engineering. A stepwise strategy combining classification and regression models was proposed, enabling simultaneous ink characterization and age estimation. This methodology is expected to provide a validated approach for classifying temporal evolution stages and predicting aging time, significantly improving the efficiency of forensic analysis in judicial investigations.
研究领域:
分析化学
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法医学
·
数据科学
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JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2025
·
IF 6.2
Donghua Xu,Yibing Wei,Haoyu Xiao,Tengyue Zhang,Zichun Sheng,Haiping Yang,Yingquan Chen,Xianhua Wang,Hanping Chen
Pyrolysis mechanisms of nitrogen (N)-containing plastics hold significant importance for recovering high-value fuels and chemicals from real plastic waste, whereas current insights remain unclear. This work systematically investigated the pyrolysis behaviors, volatile release characteristics, and backbone decomposition mechanisms of polyamide 6 (PA6), thermoplastic polyurethane (TPU), and polyacrylonitrile (PAN) through integrating TG-FTIR-GC/MS and density functional theory (DFT). Kinetic analysis based on Coats-Redfern and Achar methods suggested a higher average activation energy of PA6 (228 kJ/mol) compared to TPU (94 kJ/mol) and PAN (189 kJ/mol). PA6 pyrolysis predominantly produced c aprolactam (92.01 %) at 481 °C through the nucleophilic attack of terminal amino group on adjacent amide structure, forming a four-membered transition state with a free energy barrier of 217.0 kJ/mol. Owing to the lower bond dissociation energies (BDEs) of the acyloxy bonds in urethane groups compared to the alkoxy bonds in polyester structures, the hard and soft segments of TPU occurred sequential cracking at 358 and 448 °C, releasing 4,4’-diphenylmethane diisocyanate (85.12 %) and cyclopentanone (69.12 %), respectively. PAN backbone preferentially cleaved at mid-chain C-C bonds with lower BDEs, forming acrylonitrile dimer and monomer fragments, which coupled with each other and combined with hydrogen radicals to generate abundant NH 3 and fatty nitriles like 2-methylglutaronitrile, 1,3,6-hexanetricarbonitrile, and acrylonitrile. These findings elucidated the intrinsic connection between pyrolysis volatile evolution and backbone degradation mechanisms of N-containing plastics at the molecular level, thereby offering theoretical guidance for optimizing the pyrolysis process of real plastic waste to prepare high-value products.
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CHEMOSPHERE
·
2016
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IF 3.698
Qiang Wang,Lingyan Zhu,Meng Chen,Xinxin Ma,Xiaolei Wang,Junchao Xia
Bisphenol analogues are a group of chemicals which are being widely applied in industrial and household products owing to regulations on bisphenol A (BPA) in many countries. In this study, an analytical method, including extraction from complex environmental matrices, clean-up using solid phase extraction (SPE) and following-up derivatization prior to gas chromatography coupled with mass spectrometry (GC-MS), was developed to analyze seven commonly used bisphenols in sediment. Five kinds of extraction solvents , four kinds of SPE cartridges, and four kinds of SPE eluting solvents were individually tested for their performances; and the conditions for derivatizing were also optimized. Finally, C 18 cartridge was determined as the SPE cartridge and methanol was selected as extracting and eluting solvent. Acetic anhydride (AA) was used as derivatizing agent and reaction took 20 min at room temperature. The method was used successfully to measure the seven bisphenol compounds in sediment samples from Taihu Lake, China. BPA, bisphenol F and bisphenol S were detected in all sediment samples, with concentrations in the range of 3.94–33.2; 0.503–3.28 and 0.323–27.3 ng g −1 dw. Other compounds were detected at low frequencies or not detected. We provided a convenient, reliable, and sensitive method to analyze bisphenol compounds in complex environmental samples.
研究领域:
环境科学
·
分析化学
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FOOD CHEMISTRY
·
2026
·
IF 10.4
Kaixuan Ren,Xiaoqiu Zhou,Lin Feng,Pei Wu,Yang Liu,Hongyun Zhang,Yaobin Ma,Hongmei Ren,Xiaowan Jin,Weidan Jiang
E-tongue analysis shows that Isoleucine (Ile) enhances the overall flavor of flesh. • Ile affects volatile content in flesh, as shown by E-nose and GC–MS analysis. • Ile enhanced fatty acid (FA) synthesis and elevated FA content. • Ile promoted the movement of FA from lipid droplets to mitochondria for oxidation. • Ile increased adenosine phosphate content while decreasing hypoxanthine in flesh. This experiment used combination of electronic tongue, electronic nose, and gas chromatography mass spectrometry methods to analyze the impact of dietary isoleucine (Ile) on the flavor in grass carp muscle. Key findings include: Ile improved the sweetness and umami and reduced sourness and bitterness of the flesh. Ile inhibited sulfide and the relative content of volatile compounds like nonanal and hexanal in muscle. Second, Ile enhanced the content of adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate, and decreased the content of hypoxanthine. Furthermore, Ile raised the content of fatty acid (FA) and the enzymes related to FA synthesis. Based on the above results, it can be concluded that dietary Ile improved flesh flavor by reducing the relative content of volatile compounds like 1-octen-3-ol and increasing the content of FA and nucleotides, providing valuable insights into improving flesh quality. Download: Download high-res image (107KB) Download: Download full-size image
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AQUACULTURE INTERNATIONAL
·
2023
·
IF 2.9
Hong Yawen,Pan Yunyun,Zhu Qijian,Li Yongyong,Yang Huicheng,Lin Bangchu,Dong Zheyun,Lou Yongjiang,Fu Shiqian
Due to high-density farming methods and poor farming environments, freshwater fish often have poor muscle texture and a fishy odor before marketing, which impacts consumer acceptance. Short-term low-salinity seawater treatment of freshwater fish before marketing has been found to improve the quality of the fish, but the mechanisms underlying this phenomenon have not yet been revealed. In this study, metabolomics technique was used based on gas chromatography-mass spectrometry (GC–MS) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) to screen different metabolites and predict potential metabolic pathways after treatment with low-salinity seawater. The results showed that 3838 metabolites were presented in all of the carp samples, while 62 and 64 differential metabolites were found in the comparative groups (FW, SW, and CK represented freshwater, seawater and non-transient group, respectively). Additionally, 25 and 26 metabolic pathways were enriched from these groups. Glutaric acid, PC, and creatinine might be potential biomarkers. Seawater aquaculture significantly altered the lipid metabolism, nucleotide metabolism, and amino acid metabolism of carp, enhancing its freshness and having a significant impact on its quality. This study provided insights into the metabolic changes in carp under different rearing conditions and also served as a theoretical basis for salinity treatment before freshwater fish are brought to the market.
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Food Additives and Contaminants Part A-Chemistry Analysis Control Exposure & Risk Assessment
·
2023
·
IF 2.9
Xing Li,Yongyan Ji,Tiehong Zu,Xuezhe Huang,Jing Wang,Yanzhong Cao,Zongyan Cui
A method was developed for simultaneous determination of cyanide and thiocyanate in milk by gas chromatography-tandem quadrupole mass spectrometry (GC-MS/MS). Cyanide and thiocyanate were derivatized with pentafluorobenzyl bromide (PFBBr) as PFB-CN and PFB-SCN, respectively. Cetyltrimethylammonium bromide (CTAB) was employed both as a phase transfer catalyst and a protein precipitant in the sample pretreatment, which facilitates the separation of the organic and aqueous phases, and greatly simplifies the pretreatment procedures to achieve simultaneous and rapid determination of cyanide and thiocyanate. Under the optimized conditions, the limits of detection (LODs) of cyanide and thiocyanate in milk were 0.006 mg/kg and 0.015 mg/kg, and the spiked recoveries ranged from 90.1% to 98.2% and from 91.8% to 98.9% with relative standard deviations (RSDs) less than 18.9% and 15.2%, respectively. The proposed method was validated as a simple, fast and highly sensitive method for the determination of cyanide and thiocyanate in milk.
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FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Xiaona Lin,Lingshuai Kong,Hongzhen Cai,Qingfa Zhang,Dongmei Bi,Weiming Yi
The effects of the type and content of alkali/alkaline earth metals (AAEMs) on the co-pyrolysis of cellulose/high density polyethylene (HDPE) were studied using TGA and Py-GC/MS. AAEMs showed different effects on the decomposition characteristics of cellulose/HDPE mixtures. During cellulose/HDPE co-pyrolysis, AAEMs present in char could act as a base catalyst, with different catalytic effect on products distribution depending on the types of AAEMs. Na showed stronger catalytic cracking effect to promote alkenes formation compared to the use of K, Ca, and Mg. The comparison of experimental and calculated products distributions of raw cellulose/HDPE confirmed the existence of synergistic effect , which facilitated the cleavage of glycosidic linkages to form anhydrosugars and promoted the scission of HDPE chains to produce hydrocarbons. The effect of potassium on this synergy was also investigated. With increased potassium content, the yields of anhydrosugars and hydrocarbons decreased while the yields of furans and ketones increased, suggesting that potassium inhibited the cleavage of glycosidic bonds and promoted ring-opening reactions. This indicated that addition of potassium inhibited the synergy between cellulose and HDPE.
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JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2022
·
IF 3.571
Fangbo Xia,Lishan Guo,Peng Cui,Qian Xu,Junda Huang,Hongwei Zhou,Wei Shen
Short chain fatty acids (SCFAs), crucial intestinal bacterial metabolites , have been widely accepted as potential diagnostic markers in neonatal medicine. Nevertheless, it is still a great challenge to accurately quantify SCFAs in newborn fecal samples due to the huge variation of water content, limited commercial isotope-labeled internal standards and poor sensitivity. In this study, Na 2 CO 3 solution (50 μg/mL) was applied to convert the free SCFAs to SCFA sodium salts, which could prevent the loss of violate SCFAs during lyophilization process. Furthermore, N-methylbenzylamine- d 0 / d 3 was applied as the chemical derivatization regent to enhance the sensitivity and accuracy. Based on this method, the SCFA contents in meconium and neonatal fecal samples were analyzed to illustrate the change of SCFAs during the gut microbiome development. Chemical derivatization based on N-methylbenzylamine- d 0 / d 3 could not only significantly promote the sensitivity (323–1280 folds compared to free SCFAs) by promoting the ionization efficiency, but also provide one-to-one isotope internal standards. Moreover, 7 SCFAs, including acetic acid ( 2 ), n-butyric acid ( 4 ), isobutyric acid ( 5 ), 2-hydroxybutyric acid ( 11 ), 2-hydroxy-3-methylbutyric acid ( 13 ), 3-hydroxybutyric acid ( 14 ), 2-hydroxy-2-methylbutyric acid ( 17 ) were found to be significantly increased in neonatal fecal samples compared to the meconium fecal samples. All these results proved that this method could be applied for SCFA analysis in newborn fecal samples with perfect accuracy and sensitivity.
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危险品化学品经营许可证（带存储）