HYDRIDE GENERATION ATOMIC-ABSORPTION SPECTROMETRIC (HGAAS) DETERMINATION OF SELENIUM IN TERM AND PRETERM INFANT FORMULAS AVAILABLE IN THE UNITED-KINGDOM

A simple and sensitive hydride generation atomic absorption spectromet ry method is described for the determination of total selenium in infa nt formulae. Decomposition of the composite sample matrix involved ove rnight digestion with a nitric-perchloric acid mixture (10:2 mi) then heating at 150 degrees C (30 min) and 220 degrees C (60 min). No appar ent matrix interferences were encountered. The selenium levels in infa nt formulae, reported for the first time, ranged from 0.034 to 0.093 m u g/g (dry wt) for bovine casein and whey-based term powdered infant p roducts, 0.023-0.093 mu g/g (dry wt) for preterm powdered formulae and 0.027-0.049 mu g/g (wet wt) for hospital administered low birth weigh t ready-to-feed for mulae. These values are dependent on geographic or igin of bovine milk and exhibit variation between batches. Routine QC analysis and fortification by manufacturers is recommended.