Multielemental distribution patterns in premature human milk whey and pre-term formula milk whey by size exclusion chromatography coupled to inductively coupled plasma mass spectrometry with octopole reaction cell

Abstract

Size exclusion chromatography (SEC), carried out on a Superdex 200 column, has been coupled on line to a quadrupole ICP-MS instrument, equipped with an octopole reaction cell (ORC), for the multielemental speciation of several essential (P, S, Cr, Mn, Fe, Co, Cu, Zn, Br, Se and I) and toxic elements (such as Al) in premature human breast milk whey and premature infant formulae. Human milk samples were centrifuged at 31000g to obtain the milk whey. A SEC-ICP-(ORC)MS hyphenated technique was optimised and then applied to the multielemental fractionation of such elements in premature (after 28–32 gestational weeks) human milk whey at four different lactating stages, covering the first month after birth (namely: colostrum, 6th day, 14th day and 28th day milks after delivery). Similarly, the technique was also applied to essential and toxic elements fractionation in several formula milks, commercially available for feeding of premature newborns. Results of distribution patterns of the above mentioned elements in the two sample types under study (human and formula milks) are discussed. Important differences in trace element speciation between premature human and formula milks have been demonstrated for many essential elements (e.g. Cu, Fe and Zn). The nutritional significance and practical implications of such differences is highlighted from the point of view of formula milks production for premature babies.