Scientific Publications by FDA Staff

Xray Spectrom 2016 Nov-Dec;45(6):330-8

Application of high-energy polarized energy-dispersive x-ray fluorescence spectrometry to the determination of trace levels of As, Hg, and Pb in certifiable color additives.

Hepp NM, James IC

Advances in x-ray fluorescence (XRF) using high-energy polarized energy-dispersive (ED) XRF spectrometry (PEDXRF) were applied to the determination of trace As, Hg, and Pb in various color additives subject to batch certification by the U.S. Food and Drug Administration (FDA). The objectives of this study were to simplify sample preparation for quantitative determination of these elements and, if possible, to achieve improved sensitivity and detection limits compared to techniques currently used for certification. PEDXRF was compared with wavelength-dispersive x-rayfluorescence spectrometry (WDXRF) and inductively coupled plasma - mass spectrometry (ICP-MS) for the analysis of trace levels of As, Hg, and Pb in certifiable color additives. For these light matrices, PEDXRF provided better signal-to-noise and allowed quantitation in smaller amounts of color additive relative to WDXRF and equal or better precision to ICP-MS. Determination of these trace elements in a variety of color additives was possible relative to calibrations generated from one color additive using specimens prepared simply by pouring the color additive powder into an XRF sample cup.