Heavy Metal Analysis of Tattoo Ink Using Atomic Absorption Spectrometry

The FDA defines any material that can impart color to a food, drug, cosmetic, medical device, or the human body as a “color additive.” While these color additives must be pre-approved by the FDA for use (approved additives found in 21 CFR Parts 73,74, 82), no color additives have been approved for injected use. Thus there is no regulatory process in place for detecting contaminants in tattoo inks, and the FDA has historically not enforced any standards unless significant incidents are reported. The purpose of this research is to attempt to develop a method to test for trace heavy metals in these inks through Atomic Absorbance Spectrometry. Initial samples underwent acid digestion with concentrated HNO3 and H2SO4, but upon dilution for flame analysis formed small amounts of precipitate. Possibly due to these solids, initial results were highly variable even between duplicate runs. When further samples were filtered through a 0.45µm membrane syringe filter following acid digestion, detectable levels of heavy metals were still present, but varied by less than one part per million