Comparison of Different Analytical Techniques for the Determination of Organic Mercury

Abstract

Abstract Methods for the determination of (1) total organic mercury (Hg) using an extraction +neutron activation analysis, (2) the sum of methyl-Hg+phenyl-Hg using 131I−-Cl− exchange and (3) methyl-Hg using two different Westöö modifications, have been compared. Sample materials were 8 falcon livers, 5 pike livers and 2 pike muscles. Although differences were found between the methods, interaction effects caused by either sample inhomogeneity or bad performance of the analytical methods impeded a clear interpretation of the comparison. Total Hg in the samples was determined by neutron activation analysis (NAA) and atomic absorption spectrometry. The accuracy of the total Hg determination using NAA was verified by the analysis of certified reference material. In addition to the other organic Hg determinations phenyl-Hg was determined separately in some of the samples by an isotope exchange method using 203Hg2+. The main conclusion of the study was that there is a demand for reference materials certified for at least total organic Hg and methyl-Hg.