大气压化学电离质谱法测定饲料中的醋酸甲羟孕酮

醋酸甲羟孕酮(medroxyprogesteroneacetate)是一种人工合成生长激素,一般被用来生产避孕药及补充人体激素,但是如果使用过量,将影响生育功能。欧盟已经明令禁止在食物和饲料中使用醋酸甲羟孕酮。2002年7月德国首次发现从荷兰进口的生猪猪肉中含有该激素,深入的调查后发现欧盟成员国的猪饲料和一些软饮料里发现了禁用的醋酸甲羟孕酮,可能在欧盟继疯牛病、口蹄疫和二(口恶)英之后引发新的食品安全危机。为保证我国动物源性食品安全,维护人民身体健康,必须建立一种适用、可行、规范的残留检测方法以适应当前加入WIO的形势需要。本实验建立了高效液相色谱-质谱联用法(LC-MS)测定饲料中醋酸甲羟孕酮,旨在为政府从源头上监控饲料中的醋酸甲羟孕酮提供准确可靠的检测方法。     

饲料中八种磺胺药物的高效液相色谱测定

结合液、液分配和固相萃取,建立了同时分析食用动物饲料中磺胺嘧啶、磺胺甲基嘧啶、磺胺二甲嘧啶、磺胺甲氧哒嗪、磺胺甲基异唑、磺胺间甲氧嘧啶、磺胺间二甲氧嘧啶和磺胺喹啉8种磺胺类药物的高效液相色谱方法。比较和优化了不同的提取方法和净化参数,方法对饲料中磺胺的检出限为0.20×10-6(w),八种磺胺添加水平为1×10-6(w)时,回收率在68%以上,相对标准偏差小于12%。     

埃米尔·费歇尔的学术成就和贡献*

赫尔曼·埃米尔·费歇尔(Hermann Emil Fischer)是19世纪德国著名科学家、一代化学大师。他发现了苯肼,对糖、嘌呤、肽、蛋白质、立体化学及其他一些化学领域进行了广泛深入的研究,因其在糖类、嘌呤类有机化合物方面的卓越贡献,获得了1902年诺贝尔化学奖。他的研究领域集中在对有机化学中那些与人类生活、生命有密切关系的有机物质探索,提出了“锁-匙”模型,因而被称为生物化学的奠基人。本文回顾了费歇尔的学术生平与重要成就,希望对医药专业相关学术及研究者有所启迪,也希望能为药学专业开展课程思政建设提供教学资源。     

Reversal of Tabun Toxicity Enabled by a Triazole-Annulated Oxime Library—Reactivators of Acetylcholinesterase

Acetylcholinesterase (AChE), an enzyme that degrades the neurotransmitter acetylcholine, when covalently inhibited by organophosphorus compounds (OPs), such as nerve agents and pesticides, can be reactivated by oximes. However, tabun remains among the most dangerous nerve agents due to the low reactivation efficacy of standard pyridinium aldoxime antidotes. Therefore, finding an optimal reactivator for prophylaxis against tabun toxicity and for post-exposure treatment is a continued challenge. In this study, we analyzed the reactivation potency of 111 novel nucleophilic oximes mostly synthesized using the CuAAC triazole ligation between alkyne and azide building blocks. We identified several oximes with significantly improved in vitro reactivating potential for tabun-inhibited human AChE, and in vivo antidotal efficacies in tabun-exposed mice. Our findings offer a significantly improved platform for further development of antidotes and scavengers directed against tabun and related phosphoramidate exposures, such as the Novichok compounds.     

Visible Light Photoredox Catalysis Using Ruthenium Complexes in Chemical Biology

The development of bioorthogonal reactions have had a transformative impact in chemical biology and the quest to expand this toolbox continues. Herein we review recent applications of ruthenium-catalyzed photoredox reactions used in chemical biology.     

Direct Determination of Cadmium in Grain by Solid Sampling Electrothermal Vaporization Atomic Fluorescence Spectrometry with a Tungsten Coil Trap

A simple and rapid method was developed for the determination of cadmium in grain. Porous carbon was employed as an electrothermal vaporizer with a sampling boat for atomic fluorescence spectrometry with on-line ashing to eliminate matrix interferences. Grain was pulverized to a particle size less than 0.25 mm to provide good homogeneity. Pauwels’ equation was employed to determine that the minimum sample mass was approximately 2 mg. Optimal conditions for ashing (90 W and 50 s), vaporization (110 W and 20 s), and argon-hydrogen flow (0.6 L/min) were determined. Under the optimized conditions, the limit of quantification was 0.11 µg/kg, and the relative standard deviation was less than 10%. Furthermore, the mean fortified recovery in grains was between 83.5 and 107.7% (n = 6). To validate the method, cadmium was also determined in these samples by ICP-MS, and there were no significant differences between the results using the methods.