Indirect determination of cationic surfactants in frozen squid by flame and electrothermal atomisation atomic absorption spectrometry

Abstract

An indirect atomic absorption spectrometric method to determine total cationic surfactants, based on the formation of an ion pair with the tetrathiocyanate copper(II) complex, extraction into benzene and Cu determination either by flame or graphite furnace atomic absorption spectrometry, is proposed. Detection limits are 1.1 and 0.4 p.p.m. of cetyltrimethylammonium bromide for the flame and graphite furnace methods, respectively. The method was applied to the determination of the total cationic surfactant content in frozen squid assuming an average relative molecular mass of 400. The validity of the method was confirmed by comparing the results with those obtained by the two-phase titration method and from recovery studies.