Table 2.
Identification of pigments in tattoo inks and self-made mixtures
| No. | Tattoo inks—organic pigments declared at the label | Identified by average mass spectrum (AMS) | Identified by fragment comparison |
|---|---|---|---|
| 1 | None, blue color | – | P.B.15 |
| 2 | P.B.15 | P.B.15 | P.B.15 |
| 3 | P.B.15 | P.B.15 | P.B.15 |
| 4 | P.B.15 | P.B.15 | P.B.15 |
| 5 | P.B.15, P.R.170 | P.R.170 (or P.R.210) | P.R.170 (or P.R.210) |
| 6 | P.B.15, P.R.202, P.V.37 | P.V.37 | P.B.15 |
| 7 | P.G.36 | P.G.36 | P.G.36 |
| 8 | P.G.36, P.Y.154 | P.Y.154 | P.G.36, P.Y.154 |
| 9 | P.O.13, P.Y.65 | P.Y.74 (or P.Y.65) | P.Y.74 (or P.Y.65) |
| 10 | P.O.13, P.R.210 | P.R.170 (or P.R.210) | P.R.146, P.R.170 (or P.R.210) |
| 11 | P.O.16, P.Y.14 | P.O.16 | P.Y.1, P.O.16 |
| 12 | P.O.73, P.Y.138 | P.O.73 | P.O.73, P.Y.138 |
| 13 | P.O.73, P.Y.138 | P.Y.138 | P.O.73, P.Y.138 |
| 14 | P.O.73, P.Y.97, P.R.202 | P.Y.97 | P.Y.97 |
| 15 | P.R.170 | P.R.170 (or P.R.210) | P.R.170 (or P.R.210) |
| 16 | P.R.170 | P.R.170 (or P.R.210) | P.R.170 (or P.R.210) |
| 17 | P.R.177 | P.R.177 | P.R.177 |
| 18 | P.R.254 | P.R.254 | P.R.254 |
| 19 | P.R.254 | P.R.254 | P.R.254 |
| 20 | P.R.254 | P.R.254 | P.R.254 |
| 21 | P.R.254, P.R.177 | P.R.254 | P.R.177, P.R.254 |
| 22 | P.Y.14 | P.Y.14 | P.Y.74, P.Y.14 |
| 23 | P.Y.14 | P.Y.14 | P.Y.14 |
| 24 | P.Y.65 | P.Y.74 (or P.Y.65) | P.Y.74 (or P.Y.65) |
| 25 | P.Y.138 | P.B.15 | P.Y.138 |
| 26 | P.Y.138 | P.Y.138 | P.Y.138 |
| 27 | P.Y.138 | P.Y.138 | P.Y.138 |
| 28 | P.Y.154 | P.Y.154 | P.Y.154 |
| Sum | Different from declaration Missing |
2/28 inks = 7.1 % Not applicable |
3/40 pigments = 7.5 % 8/40 pigments = 20 % |
|---|---|---|---|
| Mix 1 | P.B.15, P.V.23 | P.R.254 | P.B.15, P.V.23 |
| Mix 2 | P.O.43, P.R.112 | P.R.112 | P.R.112 |
| Mix 3 | P.O.73, P.R.254 | P.R.254 | P.O.73, P.R.254 |
| Mix 4 | P.O.5, P.Y.83 | P.Y.83 | P.O.5,P.Y.83 |
| Mix 5 | P.O.16, P.Y.14 | P.Y.14 | P.O.16, P.Y.14 |
| Mix 6 | P.R.112, P.R.202, P.R.254 | P.Y.138 | P.R.112, P.R.254 |
| Mix 7 | P.R.4, P.Y.3 | P.R.4 | P.R.4, P.Y.3 |
| Mix 8 | P.R.5, P.Y.83 | P.Y.83 | P.R.5, P.Y.83 |
| Mix 9 | P.R.5, P.Y.97 | P.Y.97 | P.R.5, P.Y.97 |
| Mix 10 | P.R.5, P.Y.1 | P.R.5 | P.R.5, P.Y.1 |
| Mix 11 | P.R.22, P.Y.1 | P.Y.1 | P.R.22, P.Y.1 |
| Mix 12 | P.R.22, P.Y.74 | P.Y.74 (or P.Y.65) | P.R.22, P.Y.74 (or P.Y.65) |
| Mix 13 | P.R.122, P.Y.1 | P.Y.1 | P.Y.1 |
| Mix 14 | P.R.122, P.R.202, P.V.19 | P.R.177 | – |
| Mix 15 | P.R.254, P.Y.3 | P.Y.3 | P.R.254, P.Y.3 |
| Mix 16 | P.R.254, P.Y.74 | P.Y.74 (or P.Y.65) | P.R.254, P.Y.74 (or P.Y.65) |
| Mix 17 | P.V.19 | P.R.177 | – |
| Mix 18 | P.Y.14, P.V.23 | P.Y.14 | P.Y.14, P.V.23 |
| Sum | Wrongly identified Missing |
4/18 mixes = 22 % Not applicable |
0/37 pigments = 0 % 6/37 pigments = 16.7 % |
Two different data evaluation approaches were applied: (1) Average mass spectra (AMS): chromatograms of tattoo inks were converted into AMS and compared to an AMS library made of the 36 pigments under consideration by using the NIST MS program. The best match was taken as a possible hit for pigment identification. Percentage of wrong hits was calculated by division of false identifications by number of inks; (2) Fragment comparison: all peaks at levels of ≥0.2 % of the total peak area were compared to the NIST MS library and the spectra and molecular masses of unknown pyrolysis products (Tables S1–S11); the percentage of wrong hits was calculated by division of false identifications by the total number of pigments present in the inks. Wrongly identified pigments are marked in italics, and pigments that could not be identified in either of the methods are marked in bold as “missing”