Contamination Status and Sources of Chlorate and Perchlorate in Infant Formula Milk Powder

Our aim was to understand the pollution levels and sources of chlorate and perchlorate in infant formula milk powder and to evaluate the risk of dietary exposure to chlorate and perchlorate in infants and young children. A total of 165 batches of samples were collected from the water, cow milk, and ingredients used, as well as 131 batches of infant formula milk powder. Chlorate and perchlorate in each sample were detected using liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the data obtained were statistically analyzed. The results showed that chlorate and perchlorate were undetectable in the water samples. Cow milk was more severely polluted by perchlorate than by chlorate. Some ingredients were also found to contain chlorate and perchlorate. Infant formula milk powder was contaminated with chlorate and perchlorate, with average contents of 34.3 and 14.5 μg/kg, respectively. The average dietary exposure levels to chlorate and perchlorate for infants aged 0–6 months were 0.71 and 0.28 μg/(kg·d), respectively, which were at an acceptable level. Infant formula milk powder and the raw materials used were found to be contaminated by chlorate and perchlorate.