Direct determination of lead in human milk by electrothermal atomic absorption spectrometry

Infants are particularly sensitive to the toxic effects of lead. Since milk is their only or main food it is important to know the contribution of milk to lead intake. The purpose of this study was to develop a direct method for determining the lead content of human milk by electrothermal atomic absorption spectrometry when a deuterium lamp is the only background correction available. The optimum conditions for lead determination in breast milk: sample dilution in Triton ×-100, modifier (75 μg of palladium) and nitric acid contents (2%) and the graphite furnace program (mineralization: 1100°C; atomization: 2300°C) were selected. The analytical parameters are: linearity (20–300 ng ml−1); detection limit (5.0 ng ml−1); precision (intra-assay 11.7%) and recovery percentage (109.8±5.4%), and they show that the method is useful for determining lead in human milk.