Determination of arsenic, chromium, lead, manganese, and mercury in certifiable color additives by inductively coupled plasma/mass spectrometry.

Specifications in the Code of Federal Regulations limit the levels of As, Pb, and Hg in most certifiable color additives, and some have additional specification limits for Cr and Mn. A new ICP/MS method was developed and validated for the quantitative determination of these elements in various certifiable color additives. One dissolution and two microwave-assisted digestion sample preparation procedures were optimized to address initial low Hg and enhanced As recoveries. Results using the three sample preparation procedures were generally equivalent for all of the elements determined. LOQ values were 0.3 mg/kg for As, 0.7 mg/kg for Cr, 0.4 mg/kg for Pb, 0.7 mg/kg for Mn, and 0.1 mg/kg for Hg.