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

摘要

A study was carried out about the use of different surfactants such as glycerol, saponin, sodium dodecylbenzenesulphonate (NaDBS), Triton X-100, and viscalex, 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 milk and infant formula, respectively. For calibration, the method of standard additions was used. The limits of detection obtained for the cow's milk and infant formula fat were 2.3 and 2.9 #mu#g/L, respectively. The coefficient of variations was 3.6 and 4.5% and the recovery obtained was between 98-108 and 93-102% for cow's milk fat and infant formula fat, respectively. The method was applied to the Zn determination in whole milk and milk fat for different cow milks and infant formulas by flame atomic absorption spectrometry (FAAS).