In vitro quantitative chemical analysis of tattoo pigments

Background: The composition of cosmetic tattoos might prove relevant to the ir treatment by high-powered lasers. Objectives: To test the accuracy and completeness of information supplied b y the tattoo ink manufacturers and to perform an elemental assay of tattoo pigments using scanning electron microscopy with energy-dispersive xray ana lysis. Design: Samples of 30 tattoo inks were examined using "standardless" energy -dispersive spectrometry. This technique uses quantitative electron x-ray m icroanalysis. The technique reliably identifies all elements with the excep tion of those elements with atomic numbers less than 11. Setting: A major national referral laboratory for microscopic examination a nd biochemical analysis of tissue. These results were compared with ink com positions compiled from manufacturer-supplied material safety data sheets. Main Outcome Measures: (1) The percentage of any given element in whole tat too pigments. (2) The presence or absence of elements and/or compounds as r ecorded in material safety data sheets supplied by the tattoo ink manufactu rers. Results: Of the 30 tattoo inks studied, the most commonly identified elemen ts were aluminum (87% of the pigments), oxygen (73% of the pigments), titan ium (67% of the pigments), and carbon (67% of the pigments). The relative c ontribution of elements to the tattoo ink compositions was highly variable between different compounds. Overall, the manufacturer-supplied data sheets were consistent with the elemental analysis, but there were important exce ptions. Conclusion: The composition of elements in tattoo inks varies greatly, even among like-colored pigments. Knowledge of the chemical composition of popu lar tattoo inks might aid the clinician in effective laser removal.