Element fractionation analysis for infant formula and food additives by inductively coupled plasma optical emission spectrometry

Abstract

Fractionation analyses are essential to investigate the effects of dietary constituents on bioavailability of elements. A sequential separation procedure has been applied for elemental fractionation patterns in infant formula, coffee cream, milk powder, whey powder and rice flour. The protein, lipid and serum fractions were separated successfully, and fractions were analysed for various essential (Fe, Cu, Zn, Mn, Mg, Ca, Cr and Co) and nonessential (Ni, V, Al, Mo, Pb, Sn, Ba and Cd) elements by ICP-OES. Basically, three main fractions namely protein, lipid and serum were separated. Organically bounded fraction was calculated from the sum of the element contents in protein and lipid fractions. The organically bounded fraction can be retained longer in the body than the other fractions, and its percentages of whole elements are between 3.8% and 92.2% in the samples. Additionally, the distribution tendency of each studied metal was variable, which is based on the sample characteristics and complexation reactivity of the metal. The organically bounded fraction for Fe, Cu, Zn and Mn is higher than the other elements in whole samples except whey powder. Investigated elements are basically included in ionic forms in whey powder. Additionally, Mg and Ca are usually observed as uncomplexed structures in the samples.