Abstract

A single-laboratory validation by inductively coupled plasma-mass spectrometry was developed for the determination total iodine (m/z 127) in infant formula and adult nutritional products. All samples were digested in nitric acid using a closed vessel microwave oven system; Te (m/z 130) was used as an internal standard. To prevent loss of iodine, ammonium hydroxide solution was added to the samples immediately after digestion. The method quantitation limit for total iodine was 0.3 ng/mL, but a practical LOQ was used at 1.0 ng/mL, a concentration at which there was a negligible bias due to nonlinearity. The total iodine concentrations (112-1900 ng/g) in 14 out of 15 nutritional products were within specification limits. Within-day and day-to-day (6 independent days) precision values were < 10% RSD. The observed precision for the overall mean (18 independent days) of a control sample was approximately 4% RSD. In two National Institute of Standards and Technology standard reference materials, total iodine results were within certified limits. Sample spike recoveries for all 15 nutritional products were 92-105%. The data show that a conventional microwave oven digestion procedure can be used to prepare samples for iodine determination. Therefore, this technique is very compatible with other methods being proposed as modern official methods for the analysis of minerals in nutritional products.

Links

Publisher Full Text

Authors

Pacquette LH, Levenson AM, Thompson JJ

Institution

Abbott Nutrition, Global Research Services, 3300 Stelzer Rd, Columbus, OH 43219, USA. lawrence.pacquette@abbott.com

Source

Journal of AOAC International 95:1 pg 169-76

MeSH

Dietary Carbohydrates
Dietary Fats
Dietary Proteins
Food, Formulated
Humans
Indicators and Reagents
Infant
Infant Food
Iodine
Limit of Detection
Mass Spectrometry
Microwaves
Nitric Acid
Powders
Quality Control
Reference Standards
Reproducibility of Results
Software
Solutions

Pub Type(s)

Journal Article

Language

eng

PubMed ID

22468356