Analysis of perchlorate in baby food on Canadian (Ottawa) markets in 2009 and estimated dietary exposure

In order to determine the baseline levels of perchlorate in major brands of baby food, 200 baby food products were collected from retail stores in Ottawa, Canada and analysed for perchlorate in 2010. The seven food groups tested were fruit, juices, vegetables, meat, yogurt, mixed (vegetable mixed with meat) and other (e.g. vegetable mixed with meat and cereal, cheese, egg,). Samples were extracted with a mixture of methanol and 1% acetic acid (4:1, v/v). Determination was conducted by stable isotope dilution ion chromatography tandem mass spectrometry (ID-IC-MS/MS). The complexity of different food matrices required additional method validation. The perchlorate levels in 46 samples were found to be lower than the quantification limit (0.2ng g(-1)). The perchlorate levels in the other 154 baby food samples were also low; about 96.7% of the baby foods had perchlorate levels less than 10ng g(-1) (ranged from 0.2 to 22.4ng g(-1), median1.35ng g(-1)); only 5 samples had perchlorate levels higher than 10ng g(-1). Dietary exposure to perchlorate from analysed baby food was conservatively estimated to range from 0.007 to 0.121 mu g/kg bw/d based on the mean intake for children (1-5years old).