BfR | Annual Report 2013
40
Faster analysis method being tested
Besides the further development of the regulation of tattoo inks, check-
ing compliance with the current Tattooing Agent Ordinance is also a
challenging objective. On the one hand, elaborate sample preparation
procedures have to be conducted in order to perform the analysis of
organic pigments that are primarily responsible for the colour. On the
other hand, objections about questionable products can only be raised
after a certain time delay. A method of rapidly identifying tattoo inks
that do not comply with the Tattooing Agent Ordinance is therefore the
objective of continuing research efforts at the BfR. The new and quicker
technique is designed to support the regional state agencies for con-
sumer and health protection in implementing the provisions of the Ger-
man Food and Feed Code.
While the majority of the currently routine techniques used in the quanti-
tative analysis of inorganic pigments require microwave-supported acid
hydrolysis of the samples, the BfR is concentrating on the Fourier trans-
form infrared spectrometry method (FTIR). This technique permits quick
qualitative identification of the organic pigments contained in tattooing
agents. By this method, the sample is exposed to a beam of infrared
light. Certain wavelengths of the infrared light are absorbed by the sam-
ple and the remaining light passing through the sample forms a spec-
trum. This is characteristic for certain chemical bonds and, through the
comparision with the reference library, it can be used in the identifica-
tion of pigments. Initial measurements of 18 commercially available tat-
too inks and seven organic pigments show that it is possible in principle
to identify organic pigments in tattoo inks using the FTIR technique.
The limitations of this method are current being systematically ana-
lysed by the BfR. Inorganic constituents for example, such as the in-
organic titanium dioxide frequently found in tattooing agents, influence
the spectrum and can complicate the interpretation of the results. If
several pigments are present in one tattooing agent, the unambiguous
identification is also decreased. Furthermore, it has been observed that
certain organic pigments exist in several variant forms that have differ-
ing FTIR spectra.
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For analysis using Fourier transform infra-
red spectrometry, a pellet is made from the
inks to be tested and then analysed.
>>
The BfR is researching methods for the rapid identification
of tattoo inks. The new methods are designed to determine
whether tattooing agents comply with the legal regulations.
