Single Laboratory Validation to Extend the Scope of AOAC Official Method 2015.06 to Indian Infant, Child and Adult Nutritional Matrices.

BACKGROUND AOAC 2015.06 is a Final Action Official Method 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-mass spectrometry (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 the Indian matrices. OBJECTIVE In this study we describe a typical Single Laboratory Validation (SLV) exercise designed to characterize the precision and accuracy of AOAC 2015.06 for common Indian nutritional matrices so that the scope of the method can be extended to include them. METHODS Six matrices specific to the Indian markets were carried through an SLV and the Standard Method Performance Requirements (SMPR) previously published for this method were used to evaluate the results. RESULTS The method demonstrated typical repeatability (<5% RSD), and intermediate precision (5-8% RSD) on the Indian matrices, with very few exceptions. Accuracy was demonstrated by overspike recoveries in the range of 90-110% over three days for the Indian matrices, as well as excellent agreement with previously published results for three additional matrices tested. Some of the new Indian matrices required alternate sample preparation procedures vs. the usual reconstitution prescribed by the SMPRs. CONCLUSIONS AND HIGHLIGHTS The SLV results showed that AOAC 2015.06 can be extended to include these Indian matrices. The two special sample preparation procedures can now be considered validated.