The determination of major and minor elements in milk and infant formula by slurry nebulisation and inductively coupled plasma - optical emission spectrometry (ICP-OES)

A method for the analysis of Ca, Cu, Fe, K, Mg, Mn, Na, P and Zn in infant formulas, milkpowders and liquid milk was developed using ICP-OES. Samples were prepared as slurries and determined against aqueous standards following Lu internal standard compensation for potential matrix effects. The instrument used was radially configured and incorporated a charge-transfer device detector allowing simultaneous acquisition of multi-element and multi-line measurements. Instrument and method performance parameters were estimated for precision, linearity, background equivalent concentrations, detection limits and accuracy. The method was found to be suitable for routine quality control monitoring of infant formulas and milkpowders, thereby improving sample throughput and analytical confidence.