A method with capillary electrophoresis coupled to mass spectrometry was optimized to determine the uptake of metformin and its metabolite guanylurea by zebrafish (Danio rerio) embryos and brown trout (Salmo trutta f. fario) exposed under laboratory conditions. Metformin was extracted from fish tissues by sonication in methanol, resulting in an absolute recovery of almost 90%. For the extraction of guanylurea from brown trout, solid-phase extraction was implemented with a recovery of 84%. The use of a mixture of methanol and glacial acetic acid as a non-aqueous background electrolyte was vital to achieve robust analysis using a bare fused-silica capillary with an applied voltage of +30 kV. Problems with adsorption associated with an aqueous background electrolyte were eliminated using a non-aqueous background electrolyte made of methanol/acetic acid (97:3) with 25 mM ammonium acetate (for zebrafish embryos) or 100 mM ammonium acetate (for brown trouts), depending on the sample complexity and matrix influences. High resolution and high separation selectivity from matrix components were achieved by optimization of the ammonium acetate concentration in the background electrolyte. An extensive evaluation of matrix effects was conducted with regard to the complex matrices present in the fish samples. They required adapting the background electrolyte to higher concentrations. Applying this method to extracts of zebrafish embryos and brown trout tissue samples, limits of detection for both metformin and guanylurea in zebrafish embryos (12.2 μg/l and 15 μg/l) and brown trout tissues (15 ng/g and 34 ng/g) were in the low μg/l or ng/g range. Finally, metformin and guanylurea could be both quantified for the first time in biota samples from exposure experiments.

优化了毛细管电泳与质谱联用的方法，以确定斑马鱼（Danio rerio）胚胎和褐鳟（Salmo trutta f。fario）对二甲双胍及其代谢物鸟脲的吸收。）在实验室条件下暴露。通过在甲醇中超声处理从鱼组织中提取二甲双胍，绝对回收率接近90％。为了从褐鳟鱼中提取鸟嘌呤脲，实施了固相萃取，回收率达84％。使用甲醇和冰醋酸的混合物作为非水本底电解质对于使用裸露的熔融石英毛细管，施加电压为+30 kV进行稳定的分析至关重要。使用由甲醇/乙酸（97：3）和25 mM乙酸铵（用于斑马鱼胚胎）或100 mM乙酸铵（用于鳟鱼）制成的非水本底电解质消除了与本底水溶液相关的吸附问题，取决于样品的复杂性和基质的影响。通过优化背景电解质中乙酸铵的浓度，实现了从基质组分的高分辨率和高分离选择性。对于鱼样品中存在的复杂基质，对基质效应进行了广泛的评估。他们需要使背景电解质适应更高的浓度。将这种方法应用于斑马鱼胚胎和褐鳟鱼组织样品的提取物中，斑马鱼胚胎（12.2μg/ l和15μg/ l）和褐鳟鱼组织（15 ng / g和34 ng / g）中二甲双胍和鸟尿素的检出限）处于低μg/ l或ng / g范围内。最后，在接触实验的生物群样品中，首次可以对二甲双胍和鸟嘌呤进行定量。