Analysis of iodine in food samples by inductively coupled plasma-mass spectrometry

ABSTRACT

This work shows a method for the determination of iodine in a variety of food samples and reference materials using inductively coupled plasma-mass spectrometry (ICP-MS) following alkaline extraction. Optimisation of the addition of organic carbon showed that a minimum of 3% 2-propanol was necessary for a constant ratio of iodine to internal standard. The limit of quantification (LOQ), calculated as 30σ for the method, was 36 ng g^–1 in solid food samples. For method validation, seven standard reference materials (SRM) and 21 fortified food samples were used. The precision (%RSD) of the measurements was in the 2–7% range. Accuracies for the SRMs were 85–105%, while the fortified food samples showed 81–119% recoveries, including a number of samples fortified at 50% of the LOQ.

Graphical Abstract

KEYWORDS:

• Iodine
• ICP-MS
• alkaline extraction
• carbon addition
• validation
• reference materials

ORCID

Todor I. Todorov http://orcid.org/0000-0002-5014-7647

Patrick J. Gray http://orcid.org/0000-0002-8248-2749