Mi-Cong Jin

Characterization comprised an eight-laboratory harmonized HPLC–DAD study, correction for Karl Fischer moisture and nominal non-volatile residue, between-vial homogeneity testing, stability assessment, and uncertainty evaluation. The HPLC–DAD-based corrected chromatographic purity estimates were 99.18 ± 0.23%, 99.33 ± 0.30%, 99.12 ± 0.30%, and 99.27 ± 0.17% (k = 2), respectively. Between-vial testing showed consistent results at a nominal 0.50 mg test portion. At 4 °C, the HPLC–DAD main-peak area fractions showed no statistically significant linear trend over 12 months, while the 50 °C stress study supported controlled-temperature storage and handling. The materials were subsequently applied to matrix-matched LC–MS/MS analysis of fortified honey, herbal-infused beverage, powdered dietary supplement, and prepared food. In honey, estimated LODs and LOQs were 0.28–0.35 and 0.95–1.20 μg/kg, respectively. Apparent process recoveries were 90.4–99.6% in honey at 2.0–20.0 μg/kg, with RSDs of 3.0–4.7% and matrix effects ranging from −13.2% to +11.7%. In the other matrices, apparent process recoveries were 92.8–96.2%, with RSDs of 3.6–4.8%. Overall, the workflow links candidate-material characterization with matrix-level analytical performance, supports the use of these materials for matrix-matched calibration and fortified-matrix quality control across the evaluated matrices, and provides a practical framework for qualifying scarce botanical-toxin calibrants.

Aconitum poisoning is a major public health concern in East Asia, and remains difficult to diagnose when the causative toxins are not covered by routine targeted assays. In a poisoning incident that occurred in 2018, 15 individuals were affected, including five fatalities, after accidentally consuming a medicinal tincture during a shared meal. The comprehensive alkaloid profile of the tincture implicated in the poisoning was achieved through the integration of targeted analysis, molecular networking, and untargeted screening based on ultra-high performance liquid chromatography coupled to time-of-flight mass spectrometry, aiming to clarify the causative agents. Targeted quantitative analysis detected nine alkaloids derived from Aconitum plants, confirming the presence of Aconitum ingredients in the medicinal tincture. However, these alkaloids were either present at low concentrations or exhibited low toxicity, and thus were not the principal causative agents of this poisoning incident. Molecular networking revealed additional hidden diester-diterpenoid alkaloids (DDAs) and monoester-diterpenoid alkaloids (MDAs) that were undetected by targeted analysis. Untargeted screening identified 58 Aconitum alkaloids, including 15 DDAs, 17 MDAs, 17 amino-diterpenoid alkaloids (ADAs), 2 C20-diterpenoid alkaloids, and seven unclassified alkaloids. The three most abundant alkaloids were structurally identified as pseudoaconitine, 8-deacetylpseudoaconitine, and 3′-methoxyacoforestinine, and were identified as the main causative agents of this poisoning. To our knowledge, this is the first detection of these alkaloids in Aconitum poisoning in China. These findings demonstrate that integrated targeted and untargeted toxicological analysis can identify undocumented toxins in poisoning events of unknown origin and clarify the chemical etiology of unusual Aconitum poisoning.

The ability to accurately analyze perfluoroalkyl substance (PFAS) levels in beef is imperative in order to effectively assess food-safety risks and ensure consumer safety because PFASs are harmful and prevalent in beef. In this study, we developed a rapid and accurate method for the simultaneously determination of the 17 PFASs in beef using dispersive solid-phase extraction (d-SPE) and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and optimized the mobile phase system, extraction solvent, and d-SPE materials. Samples were finally extracted using 0.1% (v/v) formic acid in acetonitrile, cleaned using d-SPE with PSA, C₁₈, GCB, and EMR-Lipid, separated using an Acquity Premier BEH C₁₈ column (100 mm×2.1 mm, 1.7 μm) with 0.5 mmol/L ammonium fluoride aqueous solution and methanol as the mobile phases at a flow rate of 0.3 mL/min. Analytes were detected in negative ion switching mode (ESI^-) with multiple reaction monitoring (MRM) scanning, and quantitatively analyzed using the internal standard method. The 17 PFASs exhibited linearity in the 0.2-20.0 μg/L range under the optimal experimental conditions, with correlation coefficients of 0.9915-0.9999. The method delivered limits of detection (LODs) of 0.003-0.007 μg/kg and limits of quantification (LOQs) of 0.01-0.02 μg/kg. The 17 PFASs exhibited recoveries of 71.1%-127.4% with RSDs of 0.6%-14.4% when spiked at three levels (0.05, 0.5, and 1.8 μg/kg). We optimized the mobile phase system, which revealed that, compared with 2.0, 5.0, and 10.0 mmol/L ammonium formate or ammonium acetate in aqueous methanol, 0.5 mmol/L ammonium fluoride in aqueous methanol exhibited higher sensitivities for all the 17 PFASs, with PFASs bearing long-chain carboxylic acids (C₁₀-C₁₈) showing 1-2 fold increases in sensitivity. PFASs do not dissociate in acidic environments, favoring their entry into the organic phase. Therefore, we investigated the effect of extractant acidity, which revealed that the 17 PFASs were better extracted using 0.1% (v/v) formic acid in acetonitrile. The beef matrix has a complex composition; consequently, d-SPE adsorbents were required to purify samples and reduce matrix effects. The purification effects of four adsorbents (PSA, C₁₈, GCB, and EMR-Lipid) toward the 17 PFASs and the amount of EMR-Lipid used were investigated, which revealed that 100 mg PSA+80 mg C₁₈+40 mg GCB+150 mg EMR-Lipid exhibited superior matrix-purification behavior. We also investigated the effects of various injection solutions and types of syringe filter, with pure methanol selected for reconstitution and high-speed supernatant centrifugation applied prior to injection. The developed method is simple, rapid, sensitive, and reproducible, and can be used to simultaneously, rapidly, and accurately determine various perfluoroalkyl compounds in beef.

Ion chromatography is a technique commonly used to separate strongly polar and ionizable substances; it can be used to separate, identify, and quantify ionizable compounds in complex samples when coupled with mass spectrometry, and is currently being used in the application of food analysis, drug analysis, metabolomics and clinical poisoning analysis. Herein, we review the development of ion chromatography-mass spectrometry (IC-MS), its progress over the past 20 years, and future trends in the abovementioned areas. The IC-MS research progress and applications for the determination of inorganic anions, organic acids, polar pesticides, biogenic amines, and sugars in the food field are discussed. Drug analysis applications are discussed mainly in relation to the analysis of drug impurities, identifying drug degradation products, and determination of plasma concentration, while the separation and analysis of strongly polar metabolites, such as organic acids, sugar phosphates, and nucleotides in biological matrices are discussed in relation to metabolomics. Advances in the analysis of strongly polar or ionizable toxic compounds, such as alkyl methylphosphonic acid, methylphosphonic acid, glyphosate, 3-nitropropionic acid, and indandione rodenticides, are mainly discussed in clinical poisoning analysis field. This paper is expected to become a useful reference for the further expansion and application of IC-MS in the life and health fields.

Due to the harmful effects of estrogens and their prevalence in animal foods, accurate analysis of estrogen levels in animal foods is imperative in order to effectively assess food safety risks and ensure consumer safety. Therefore, a rapid and accurate method based on PRiME HLB solid phase extraction (SPE) cartridge purification and ultra. performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed to determine nine estrogen residues in bullfrogs. The nine estrogens included estriol (E3), 17 beta-estradiol (beta-E), 17 alpha-estradiol (alpha-E), 17 alpha-ethinylestradiol (EE2), estrone (EI), diethylstilbestrol (DES), dienestrol (DE), hexestrol (HEX), and dienestrol diacetate (DD). This study optimized the mobile phase system, extraction solvent, and SPE cartridges. Because estrogens present weak alkalinity, adding a small amount of alkaline substance to the mobile phase benefits estrogen ionization into the ionic state, eliminates the peak trailing phenomenon, and enhances the signal response of estrogens to improve sensitivity. Estrogens have one or more hydroxyl groups in their chemical structures. According to the principle of similar solubility, polar solvents are chosen as extraction solvents. Based on the complex matrix composition of meat samples, SPE is required for purification to reduce matrix effects. The liquid chromatographic conditions were optimized, and the 0.5 mmol/L ammonium fluoride aqueous solution-acetonitrile system as mobile phases showed better sensitivity than the ammonium acetate aqueous solution-acetonitrile system and the ammonia-acetonitrile system for the nine estrogens. When acetonitrile was used as the extraction solvent, the extraction rates of all nine estrogens exceeded those of methanol and ethyl acetate and increased by 15%-40%. By focusing on the matrix purification effect of four different SPE cartridges, the results showed that the matrix purification ability of the PRiME HLB cartridge outperformed that of the HLB, C-18, and Silica SPE cartridges. After purification by the PRiME HLB cartridge, the recoveries of all compounds were in the range of 70% -125%, and the DD recovery was increased from 47% to 74%, whereas the HEX recovery was reduced from 180% to 123%. Therefore, the PRiME HLB SPE cartridge was selected as the cleanup material for this experiment. Finally, the sample was extracted using acetonitrile, purified by PRiME HLB SPE cartridge, and separated on a Waters Acquity UPLC BEH C-18 column (100 mm x 2.1 mm, 1.7 mu m) with a mobile phase of 0.5 mmol/L ammonium fluoride aqueous acetonitrile solution at a flow rate of 0.3 mL/min. The detection was conducted in positive and negative ion switching mode (ESI+/ESI-) and multiple reaction monitoring (MRM) scanning, and it was quantified using a matrix-matched external standard method. Under the optimal experimental conditions, the linear ranges were 0.5 - 100.0 mu g/L for E3, beta-E, alpha-E, EI, DE, HEX, and DD, and 1.0-100.0 mu g/L for EE2 and DES. The nine estrogens showed good linearity in all linear ranges, with correlation coefficients of 0.9953-0.9994. The limits of detection were 0.17-0.33 mu g/kg, and the limits of quantification were 0.5-1.0 mu g/kg. The recoveries of the nine estrogens spiked at the three spiked levels of low (2.0 mu g/kg), medium (10.0 mu g/kg), and high (80.0 mu g/kg) were 107.4% - 125.3%, 67.0% - 123.3%, and 65.1% -128.2%, respectively. The relative standard deviations were 1.9% - 17.6%. The method established in this study was applied to detect nine estrogen residues in 50 commercially available bullfrog samples, and the results showed that HEX, EI, and DES were detected in few samples. The method is simple, rapid, sensitive, and reproducible, and can be used for the simultaneous, rapid and accurate determination of large quantities of samples.

建立了分散固相萃取-超快速液相色谱-串联质谱法同时测定板栗粉和小麦粉中43种真菌毒素的方法,对48份板栗粉和80份小麦粉样品的污染状况进行调查,筛选出5种专属于小麦粉的标志性真菌毒素。样品采用84%(v/v)乙腈水溶液提取,提取液采用C₁₈结合增强型脂质去除净化剂(EMR-Lipid)净化,采用响应曲面-中心组合设计优化分散固相萃取净化方法。净化液在BEH C₁₈色谱柱(100 mm×2.1 mm, 1.7 μm)上分别采用0.1%甲酸水溶液和含0.1%甲酸的甲醇-乙腈(1:1, v/v)(电喷雾正离子模式)、水和乙腈(电喷雾负离子模式)为流动相进行梯度洗脱,分别采用电喷雾电离(ESI)正负离子模式检测,基质匹配曲线外标法定量。板栗粉中真菌毒素的3水平加标回收率在72.4%~109.4%之间,相对标准偏差(RSD)<7.5%;小麦粉中真菌毒素的3水平加标回收率在70.7%~112.9%之间,RSD<9.3%;两种基质中43种真菌毒素的定量限均在0.1~20.0 μg/kg之间,方法线性相关系数均大于0.9991。利用所建立的方法监测了128份样品,结果表明,两种基质普遍受到真菌毒素污染,其中脱氧雪腐镰刀菌烯醇及其衍生物3-乙酰化-脱氧雪腐镰刀菌烯醇、15-乙酰化-脱氧雪腐镰刀菌烯醇、雪腐镰刀菌烯醇、去环氧-脱氧雪腐镰刀菌烯醇仅在小麦粉中检出。采用GB 5009.111-2016同位素稀释液相色谱-串联质谱法验证,检测结果与本方法一致。所建立的方法简便、快速、灵敏、准确,可有效满足板栗粉和小麦粉中真菌毒素残留的检测要求,脱氧雪腐镰刀菌烯醇及其4种衍生物可以作为两种食品的掺假标志物。