The use of emulsions in the direct determination of zinc in milk fat by FAAS

A study was carried out about the use of different surfactants such as glyc erol, saponin, sodium dodecylbenzenesulphonate (NaDBS), Triton X-100, and v iscalex, in the emulsion preparation of milk fat. NaDBS was selected as the most suitable agent at 1.1 and 0.01% (w/v) for fat in cow's mill; and infa nt formula, respectively. For calibration, the method of standard additions was used. The limits of detection obtained for the cow's milk and infant f ormula fat were 2.3 and 2.9 mu g/L, respectively. The coefficient of variat ions was 3.6 and 4.5% and the recovery obtained was between 98-108 and 93-1 02% for cow's milk fat and infant formula fat, respectively. The method was applied to the Zn determination in whole mill; and milli fat for different cow milks and infant formulas by flame atomic absorption spe ctrometry (FAAS).