Hydride generation atomic absorption spectrometric (HGAAS) determination of selenium in term and preterm infant formulae available in the United Kingdom

A simple and sensitive hydride generation atomic absorption spectrometry method is described for the determination of total selenium in infant formulae. Decomposition of the composite sample matrix involved overnight digestion with a nitric-perchloric acid mixture (10:2 ml) then heating at 150 °C (30 min) and 220 °C (60 min). No apparent matrix interferences were encountered. The selenium levels in infant formulae, reported for the first time, ranged from 0.034 to 0.093 μ/g (dry wt) for bovine casein and whey-based term powdered infant products, 0.023–0.093 μg/g (dry wt) for preterm powdered formulae and 0.027–0.049 μ/g (wet wt) for hospital administered low birth weight ready-to-feed formulae. These values are dependent on geographic origin of bovine milk and exhibit variation between batches. Routine QC analysis and fortification by manufacturers is recommended.