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

BACKGROUND: 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. OBJECTIVE: 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. METHOD: 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. 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. CONCLUSIONS: The SLV results showed that AOAC Method 2015.06 can be extended to include these Indian matrices. HIGHLIGHTS: The two special sample preparation procedures can now be considered validated.

Single-Laboratory Validation of AOAC Official Method 2011.10 for Vitamin B12 in 'Indian' Infant and Pediatric Formulas and Adult Nutritionals.

BACKGROUND: Ensuring the quality of infant and pediatric formulas and adult nutritionals is of utmost importance for the health and safety of rapidly urbanizing Indian population. B12 is an important water-soluble vitamin, which is fortified externally in such nutritional formulations. The Bureau of Indian Standards (BIS) has a recommended microbiological assay-based method for determination of vitamin B12 that is not precise and accurate enough to meet the label claim requirements of infant, adult, and/or pediatric nutritionals. The AOAC Official Method 2011.10 was originally developed under the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) for the determination of vitamin B12 in infant and pediatric formulas and adult nutritionals. However, those SPIFAN matrixes did not contain malt and other indigenous cereal and legume flour (with or without cocoa powder), which are commonly found in Indian formulations. Thus, there is a need to replace this method with a more precise and accurate method. OBJECTIVE: This study was undertaken to validate the AOAC Official Method 2011.10 on vitamin B12 in 'Indian' infant and pediatric formulas and adult nutritionals. METHODS: The single-laboratory validation (SLV) of AOAC Method 2011.10 was carried out as per the AOAC Guidelines in six Indian pediatric and adult nutritional formulas to verify its fitness for purpose. Cobalamin in the sample was converted to cyanocobalamin on treatment with potassium cyanide. The sample was then subjected to clean up through a C18 cartridge. Vitamin B12 in the eluted extract was separated from other components using size-exclusion column chromatography followed by a C18 column. The HPLC analysis was carried out at 550 nm. RESULTS: Diastase treatment and C18 solid-phase extraction cleanup satisfactorily removed the matrix interference. The relative standard deviation of the determined values in 30 samples each from 6 selected Indian products and NIST SRM 1849a was <20%. The average recoveries for the spiked recovery samples ranged from 91.75 to 101.14%. CONCLUSIONS: Method 2011.10 met the standard method performance requirements set forth by the AOAC SPIFAN. Therefore, we recommend the Method 2011.10 for adoption as the BIS official method for the analysis of vitamin B12 in 'Indian' infant and pediatric formulas and adult nutritionals. HIGHLIGHTS: This was the first SLV project that the AOAC India section undertook to extend the scope of the AOAC Method 2011.10 for vitamin B12 analysis by validating it in 'Indian' infant and pediatric formulas and adult nutritionals.