Midskov C
J Chromatogr. 1987 Jan 23;413:189-98. doi: 10.1016/0378-4347(87)80226-8.
This paper describes sensitive, selective and precise methods for the assay of fenflumizole and its chromatographically verified demethyl and didemethyl metabolites in whole blood, isolated red blood cells, plasma, saliva, urine and tissue (skin and fat) from human subjects. Also conjugates of the two metabolites with glucuronic acid and sulphate were assayable. The compounds were quantitated by means of reversed-phase liquid chromatography after diethyl ether extraction, followed by fluorescence and/or electrochemical detection. The assay using fluorescence detection is quantitative down to ca. 150 pg/ml; with electrochemistry this limit was ca. 600 pg/ml and included the demethyl metabolites only. Proteinaceous materials show an extraction yield of 70-75%, whereas analytes in sample materials without proteins show yields of better than 95%. The precision at concentration levels of ca. 50 ng/ml for the parent compound and ca. 5 ng/ml for the metabolites is at most 6% (relative standard deviation) with both detection modes. The analytical procedures developed were applied after both single and repetitive administration of fenflumizole. The administration of 14C-labelled fenflumizole in the single-dose study revealed the presence in plasma and urine of as yet unknown metabolites. The in vivo retention time of 14C activity was substantially greater in the blood cells than in plasma. Measurements of 14C activity in excreta demonstrated that excretion via the faeces is the preferred route.
本文描述了灵敏、选择性强且精确的方法，用于测定人受试者全血、分离的红细胞、血浆、唾液、尿液及组织（皮肤和脂肪）中芬氟米唑及其经色谱验证的去甲基和双去甲基代谢物。两种代谢物与葡萄糖醛酸和硫酸盐的缀合物也可进行测定。通过乙醚萃取后，采用反相液相色谱法对化合物进行定量，随后进行荧光和/或电化学检测。采用荧光检测的测定方法定量下限约为150 pg/ml；采用电化学检测时，此下限约为600 pg/ml，且仅包括去甲基代谢物。含蛋白质物质的萃取率为70 - 75%，而不含蛋白质的样品物质中分析物的萃取率高于95%。两种检测模式下，母体化合物浓度约为50 ng/ml、代谢物浓度约为5 ng/ml时的精密度最高为6%（相对标准偏差）。所开发的分析方法在单次和重复给予芬氟米唑后均得到应用。单剂量研究中给予14C标记的芬氟米唑显示，血浆和尿液中存在尚未明确的代谢物。血细胞中14C活性的体内保留时间显著长于血浆。排泄物中14C活性的测量表明，粪便排泄是主要途径。
