Single-Laboratory Validation to Extend the Scope of AOAC Official MethodSM 2015.06 to Indian Infant, Child, and Adult Nutritional Matrixes.

Abstract

AOAC Method 2015.06 is a Final Action Official MethodSM for the determination of 12 elements (Na, Mg, P, K, Ca, Cr, Mn, Fe, Cu, Zn, Se, and Mo) in infant formula and adult nutritional products, based on inductively coupled plasma (ICP)-MS. Currently, its scope does not include certain kinds of formulations used in India. The method would likely be used more in Indian laboratories if its performance were characterized on Indian matrixes. In this study we describe a typical single-laboratory validation (SLV) exercise designed to characterize the precision and accuracy of AOAC Method 2015.06 for common Indian nutritional matrixes so that the scope of the method can be extended to include them. Six matrixes specific to the Indian market were carried through an SLV and the Standard Method Performance Requirements (SMPRs®) previously published for this method were used to evaluate the results. The method demonstrated typical repeatability (<5% RSD), and intermediate precision (5-8% RSD) on the Indian matrixes, with very few exceptions. Accuracy was demonstrated by overspike recoveries in the range of 90-110% over 3 days for the Indian matrixes, as well as excellent agreement with previously published results for three additional matrixes tested. Some of the new Indian matrixes required alternate sample preparation procedures versus the usual reconstitution prescribed by the SMPRs. The SLV results showed that AOAC Method 2015.06 can be extended to include these Indian matrices. The two special sample preparation procedures can now be considered validated.