Total iodine in infant formula and nutritional products by inductively coupled plasma/mass spectrometry: First Action 2012.14

Abstract

After an assessment of data generated from a single-laboratory validation study published in the Journal of AOAC InternAtIOnAl 95, 169-176(2012), a method for determining the total level of iodine in infant formula and nutritional products was presented for consideration for adoption by AOAC during the AOAC Annual Meeting held September 30-October 3, 2012 in Las Vegas, NV. An Expert Review Panel on Infant Formula and Adult Nutritionals concluded that the method met the established standard method performance requirements, and approved the method as AOAC Official First Action. The method involves digestion of the sample with nitric acid in a closed vessel microwave oven, followed by determination by inductively coupled plasma/MS using tellurium as the internal standard. The method LOQ for total iodine was 1.5 μg/100 g, but a practical LOQ was used at 5 μg/100 g total iodine. The analytical range of the method was 5-100 μg/100 g total iodine. The recoveries from 15 spiked nutritional products ranged from 90 to 105%.