An innovative voltammetric approach to the detection of cholic and chenodeoxycholic acids is presented. These two primary bile acids are important biomarkers of liver function in humans and are involved in many physiological processes in the human body. Herein we describe a way to reproducibly convert the hard-to-detect bile acid molecule into an easily detectable derivative in situ using 0.1 M HClO4 in acetonitrile (water content 0.55%). Under these conditions the bile acids are dehydrated and the resulting alkenes can be subsequently oxidized electrochemically on polished boron-doped diamond electrode under unchanged conditions at approximately +1.2 V vs. Ag/AgNO3 in acetonitrile. After optimization, differential pulse voltammetry provides competitive limits of detection of 0.5 µM and 1.0 µM for cholic and chenodeoxycholic acid, respectively, with a linear course of calibration dependency to the minimum of 80 µM. The method was applied for detection of cholic and chenodeoxycholic acids in artificial and human serum samples using single solid phase extraction on C-18 cartridge for preliminary separation of the analytes. High recoveries of 80-90% were consistently obtained by the proposed voltammetric method and reference HPLC with fluorescence detection for human serum samples, confirming good selectivity for real-life samples.

中文翻译：

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一种新颖的伏安法检测血清样品中的胆汁酸。

介绍了一种新颖的伏安法检测胆酸和鹅去氧胆酸。这两种主要的胆汁酸是人类肝功能的重要生物标志物，并参与人体的许多生理过程。本文中，我们描述了一种方法，该方法使用0.1 M HClO4的乙腈溶液（水含量0.55％）可重复地将难于检测的胆汁酸分子原位转化为易于检测的衍生物。在这些条件下，胆汁酸脱水，随后可以在不变的条件下，相对于乙腈中的Ag / AgNO3，在约+1.2 V的条件下，在抛光的掺硼金刚石电极上将所得的烯烃进行电化学氧化。经过优化后，差分脉冲伏安法提供的竞争性检测极限分别是胆酸和鹅去氧胆酸的0.5 µM和1.0 µM。校准相关性的线性过程最小为80 µM。该方法适用于在C-18柱上进行单一固相萃取以分离分析物的人工和人类血清样品中的胆酸和鹅去氧胆酸。通过建议的伏安法和带荧光检测的参考HPLC对人血清样品一致地获得了80-90％的高回收率，证实了对现实生活中样品的良好选择性。