Determination of selenium in human milk by hydride cold-trapping atomic absorption spectrometry and calculation of daily selenium intake

A technique of hydride cold-trapping atomic absorption spectrometry followi ng microwave digestion was developed and optimized for the determination of selenium in human milk. The method was validated by the analysis of two st andard reference materials (CRM milk powder). The detection limit was 0.5 n g mL(-1). The method was then used to analyze 78 milk samples from 38 Austr ian mothers throughout their first 10 months of lactation. The mean concent ration of selenium in the mother's milk decreased with the days postpartum from 23.9 +/- 12.0 mu g L-1 in colostrum to a plateau of 11.4 +/- 3.0 mu g L-1 in mature milk. On the basis of the milk selenium concentrations, the s elenium intakes of the fully breast-fed infants and the lactating mothers w ere calculated. The selenium intake of the infants during their first 3 mon ths of life was >8.2 mu g day(-1). The selenium intake of the lactating mot hers was 48 mu g day(-1). Compared to the recommended dietary allowance, th e fully breast-fed infants received sufficient selenium but the lactating m others obtained less than the recommended.