2021 FDA Science Forum
Mercury Determination in Certifiable Color Additives Using Thermal Decomposition Amalgamation and Atomic Absorption Spectrometric Analysis
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Contributing OfficeCenter for Food Safety and Applied Nutrition
Abstract
Background:
Color additives requiring batch certification by the U.S. Food and Drug Administration (FDA) have Code of Federal Regulations (CFR) specification limits for certain elements and are usually analyzed by x-ray fluorescence spectrometry (XRF). However, sensitivity for mercury (Hg) is too low in some color additives.
Purpose:
The aim of this study was to evaluate the effectiveness of thermal decomposition amalgamation-atomic absorption spectrometric (TDA-AAS) for analysis of Hg in the various types of certifiable color additives as part of FDA’s color certification program.
Methodology:
Tests were performed to optimize conditions and test reliability of Hg determinations at and below the CFR specification limit of 1 mg/kg.
Results:
Factors that affected results were appropriateness of the calibration procedure and condition of the catalyst, which was sample matrix dependent. Regular quality checks using certified reference materials and in-house matrix-matched check standards are essential.
Conclusion:
The TDA-AAS method can be used for determining Hg concentrations at and below the CFR specification limit in all color additives, including those that are difficult to analyze by XRF. However, it is less efficient for color additives containing nitrogen, sulfur, and halogens, which quickly deteriorate the catalyst. Color additives containing BaSO4 that are difficult to analyze by other techniques are well suited for TDA-AAS analysis.
