A routine quality control method for the determination of iodine in human and pet food by ICP-MS

A rapid, robust ICP-MS method is described for the determination of iodine in human as well as pet food. The sample preparation is made by alkaline hy drolysis with tetramethylammonium hydroxide using either microwave heating or the high pressure asher. Method validation was carried out using seven r eference food materials with certified iodine content, and by cross-validat ion with gas chromatography, neutron activation analysis, and colorimetry. The method has been proven to give accurate and repeatable results for a ra nge of fortified human and pet food products, and to be useful in the envir onment of a central quality control laboratory.