Determination of total arsenic was strongly influenced by the properties of the spesies. In a sample of tuna fish, the total arsenic
concentration (90-95%) mostly comes from organic arsenic species, arsenobetain (AB). AB in particular, was not decomposed to
arsenate which can lead to a serious error in quantification when a hydride generator step is additionally used in the analysis
scheme. This research was done to compare three different types of sample preparations, namely dry ashing, water extraction,
and microwave digestion, for measuring the total arsenic using HG-QF-AAS, GF-AAS and ICP-MS measurements. HG-QFAAS
and ICP-MS gave similar concentrations of total arsenic in a tuna fish sample, which were 3.49±0.08 µg g-1 and 3.56±0.014
µg g-1, respectively. Meanwhile, the result from GF-AAS measurements was about a half of the others. The results of this
research can be used as a reference for determination of total arsenic in tuna fish samples.