Analyte Extension Method Validation of Elemental Analysis Manual Method 4.7 for Six Additional Elements, Cobalt (Co), Strontium (Sr), Thallium (Tl), Tin (Sn), Uranium (U) and Vanadium (V).

BACKGROUND: An interlaboratory study was conducted at the U.S. Food and Drug Administration's (FDA) Northeast Food and Feed Laboratory (NFFL) and the Center for Food Safety and Applied Nutrition (CFSAN) with the purpose to expand FDA Elemental Analysis Manual (EAM) method 4.7 (Inductively Coupled Plasma-Mass Spectrometric Determination of Arsenic, Cadmium, Chromium, Lead, Mercury, and Other Elements in Food Using Microwave Assisted Digestion) to include new analytes (1).

OBJECTIVE: The goal of the study was to demonstrate the performance of FDA EAM method 4.7 when analyzing new analytes cobalt (Co), strontium (Sr), thallium (Tl), tin (Sn), uranium (U) and vanadium (V). This analyte extension method validation of EAM 4.7 for six additional elements, Co, Sr, Tl, Sn, U and V followed all guidelines for a Level 2 or single laboratory validation and met all acceptance criteria for analyte extensions as per the Guidelines for the Validation of Chemical Methods (3).

METHOD: As per EAM 4.7 (1), this study followed the procedures and used specified equipment operated under recommended conditions. The analyte extension method validation was performed per protocol and with no deviations.

RESULTS: All quality control (QC) requirements for this analyte extension method validation of EAM 4.7 passed as evidenced by the analytical data. The results presented demonstrate accuracy, linearity and precision by successful analyses of method blanks, matrix spikes, unfortified test samples and reference materials. The data analyzed met each of the validation requirements for each analyte in all representative matrices.

CONCLUSION: The study showed that the new analytes performed satisfactorily using EAM 4.7 for total acidic extractable elemental analysis of food according to FDA's guidelines (3).

HIGHLIGHTS: The method met or exceeded the performance criteria.