本文件规定了一种定量饮用水和淡水样品中12种微囊藻毒素变体（微囊藻毒素-LR、-LA、-YR、-RR、-LY、-WR、-HtyR、-HilR、-LW、-LF、[Dha7]-微囊藻毒素-LR和[Dha7]-微囊藻毒素-RR）的方法。微克/升到1.6？微克/升。该方法可用于测定其他微囊藻毒素，前提是已经针对每种微囊藻毒素测试和验证了色谱和质谱检测的分析条件。使用内标校准通过LC-MS/MS分析样品。 这种方法是基于性能的。允许实验室修改方法，例如增加低干扰样品的直接进样体积或稀释样品以增加工作范围上限，前提是满足该方法中的所有性能标准。高分辨质谱法检测微囊藻毒素？（HRMS）作为串联质谱的替代方法？（MS/MS）见附件？A. 基于在线固相萃取与液相色谱相结合的另一种自动化样品制备方法见附录？B. 当仪器灵敏度不足以达到直接流动注射的方法检测限时，固相萃取净化和浓缩步骤见附录？C.

This document specifies a method for the quantification of twelve microcystin variants (microcystin-LR, -LA, -YR, -RR, -LY, -WR, -HtyR, -HilR, -LW, -LF, [Dha⁷]-microcystin-LR, and [Dha⁷]-microcystin-RR) in drinking water and freshwater samples between 0,05？μg/l to 1,6？μg/l. The method can be used to determine further microcystins, provided that analytical conditions for chromatography and mass spectrometric detection has been tested and validated for each microcystin. Samples are analysed by LC-MS/MS using internal standard calibration. This method is performance based. The laboratory is permitted to modify the method, e.g. increasing direct flow injection volume for low interference samples or diluting the samples to increase the upper working range limit, provided that all performance criteria in this method are met. Detection of microcystins by high resolution mass spectrometry？(HRMS) as an alternative for tandem mass spectrometry？(MS/MS) is described in Annex？A. An alternative automated sample preparation method based on on-line solid phase extraction coupled to liquid chromatography is described in Annex？B. When instrumental sensitivity is not sufficient to reach the method detection limits by direct flow injection, a solid phase extraction clean-up and concentration step is described in Annex？C.