Since there is no certified reference material available for lowlevel
CH3Hg+ in water, the accuracy of the method was verified by comparing the results with the results
obtained with gas chromatography — cold vapor atomic fluorescence spectrometry (GC-CV-AFS) based on the
EPA method 1630. The results obtained with the two different methods were in good agreement with each
other (r2=0.87, n=25) and the method was successfully applied to non-filtered humic-rich natural waters.