“…Various methods are used for arsenic measurement, including mass, optical emission, atomic absorption, atomic florescence spectrometric methods, neutron activation analysis, X ray florescence, particle induced X ray emission and secondary ion mass spectrometry. 8,[11][12][13][14][15][16][17][18][19] As the role of different chemical forms and species of the element can essentially differ, speciation analysis, metabolism and toxicity, 4,6,8,12,14,20 markers, sorbents, digestion, fractionation and extraction 15,19,[21][22][23] are of interest. From 10 to 2 percent accuracy of the measurements is often required 9,18 and methods of measurement of good reproducibility and low measurement uncertainty are highly appreciated.…”