Department of Pharmacology and Toxicology, National Veterinary Research Institute (PIWet), Pulawy, Poland.
J Sep Sci. 2017 Mar;40(5):1158-1166. doi: 10.1002/jssc.201600928. Epub 2017 Feb 8.
In this study, a new method for the determination of 12 nitroimidazoles and their hydroxymetabolites (metronidazole, hydroxymetronidazole, dimetridazole, ronidazole, hydroxydimetridazole, ipronidazole, hydroxyipronidazole, carnidazole, ornidazole, secnidazole, ternidazole, tinidazole) in beeswax has been developed and validated. The optimized sample preparation procedure included melting and dilution of beeswax in a mixture of n-hexane and isopropanol followed by extraction with 2% acetic acid. The extracts were purified on strong cation exchange based solid-phase extraction cartridges and evaporated in a vacuum system with vortex motion. The separation and detection of the nitroimidazoles in the beeswax extracts were achieved within 12 min by liquid chromatography tandem mass spectrometry using a pentafluorophenyl analytical column and applying a gradient elution with acetonitrile and 0.01% acetic acid as mobile phases. The method performance characteristics were evaluated at three concentration levels (1, 2, and 5 μg/kg) and the method was found to be suitable for determination of all tested nitroimidazoles. The limits of detection and quantification were 0.2-0.5 and 0.5-1 μg/kg, respectively. The recoveries varied from 71.2 to 104.9% while the relative standard deviations were less than 13.8% under the intermediate precision conditions.
本研究建立并验证了一种检测蜂蜡中 12 种硝基咪唑类药物及其羟基代谢物（甲硝唑、羟基甲硝唑、二甲硝唑、罗硝唑、羟基二甲硝唑、异丙硝唑、羟基异丙硝唑、卡硝唑、奥硝唑、塞克硝唑、替硝唑、替硝唑）的新方法。优化后的样品前处理程序包括在正己烷和异丙醇的混合物中融化和稀释蜂蜡，然后用 2%乙酸进行提取。提取物用基于强阳离子交换的固相萃取小柱净化，并用带有涡旋运动的真空系统蒸发。通过液相色谱-串联质谱法，在 12 分钟内即可在五氟苯基分析柱上分离和检测蜂蜡提取物中的硝基咪唑类药物，并使用乙腈和 0.01%乙酸作为流动相进行梯度洗脱。在三个浓度水平（1、2 和 5 μg/kg）下评估了方法性能特征，结果表明该方法适用于所有测试的硝基咪唑类药物的测定。检测限和定量限分别为 0.2-0.5 和 0.5-1 μg/kg。在中间精密度条件下，回收率在 71.2%至 104.9%之间，相对标准偏差小于 13.8%。
