Identification and hazard prediction of tattoo pigments by means of pyrolysis—gas chromatography/mass spectrometry

Abstract

The implementation of regulation for tattoo ink ingredients across Europe has generated the need for analytical methods suitable to identify prohibited compounds. Common challenges of this subject are the poor solubility and the lack of volatility for most pigments and polymers applied in tattoo inks. Here, we present pyrolysis coupled to online gas chromatography and electron impact ionization mass spectrometry (py-GC/MS) as quick and reliable tool for pigment identification using both purified pigments and tattoo ink formulations. Some 36 organic pigments frequently used in tattoo inks were subjected to py-GC/MS with the aim to establish a pyrogram library. To cross-validate pigment identification, 28 commercially available tattoo inks as well as 18 self-made pigment mixtures were analyzed. Pyrograms of inks and mixtures were evaluated by two different means to work out the most reliable and fastest strategy for an otherwise rather time-consuming data review. Using this approach, the declaration of tattoo pigments currently used on the market could be verified. The pyrolysis library presented here is also assumed suitable to predict decomposition patterns of pigments when affected by other degradation scenarios, such as sunlight exposure or laser irradiation. Thus, the consumers’ risk associated with the exposure to toxicologically relevant substances that originate from pigment decomposition in the dermal layers of the skin can be assessed. Differentiation between more or less harmful pigments for this field of application now will become feasible.Electronic supplementary materialThe online version of this article (doi:10.1007/s00204-016-1739-2) contains supplementary material, which is available to authorized users.

Identification of pigments related to allergic tattoo reactions in 104 human skin biopsies

“…23 are—classified as sensitizers either by manufacturers or by the European Chemical Agency (Figure D). Among these sensitizers, known carcinogens such as aniline and 3,3'‐dichlorobenzidine were also found. Aniline presents the simplest primary aromatic amine and is cleaved off by a multitude of pigments.…”

“…The pigments found in this study are known to be cleaved upon sun- Figure 2D). Among these sensitizers, known carcinogens such as aniline and 3,3'-dichlorobenzidine 14,25,[28][29][30] were also found. Aniline presents the simplest primary aromatic amine and is cleaved off by a multitude of pigments.…”

Identification of organic pigments in tattoo inks and permanent make-ups using MALDI-TOF mass spectrometry

“…Method validation and using the MALDI method for market surveys demonstrated that the method described is fit for purpose. Therefore, LDI/MALDI-TOF MS is a further powerful tool particularly in combination with py-GC/MS 10 , HPLC or ultraviolet–visible spectroscopy 18 for enforcing legal restrictions on pigments in tattoo inks and PMUs. It should be kept in mind, however, that the presented method gives no information on the levels of the detected organic pigments.…”

“…Raman spectroscopy has also been used for matching the profile of tattoo inks with dermatome shave biopsies from patients with allergic reactions 9 . Another recent paper describes the successful use of pyrolysis gas chromatography (py-GC/MS) 10 . While FT-IR and Raman Spectroscopy are very suitable for the identification of single pigments, their successful use for pigment mixtures, often present in tattoo inks, has yet to be proved.…”

Matrix-assisted laser desorption/ionization tandem mass spectrometry for identification of organic tattoo pigments in inks and tissue samples

“…Pyrolysis-gas chromatography mass spectrometry ( py-GC/MS) is a further approach helpful in the analysis of tattoo inks. 9,10 Yet, a major drawback of this is the requirement of characteristic cleavage patterns for pigment identification.…”