NBN ISO 22104:2021

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.