Tattoo inks are complex mixtures of ingredients. Each of them possesses different chemical properties which have to be addressed upon chemical analysis. In this method for two-step pyrolysis online coupled to gas chromatography mass spectrometry (py-GC-MS) volatile compounds are analyzed during a first desorption run. In the second run, the same dried sample is pyrolyzed for analysis of non-volatile compounds such as pigments and polymers. These can be identified by their specific decomposition patterns. Additionally, this method can be used to differentiate original from counterfeit inks. Easy screening methods for data evaluation using the average mass spectra and self-made pyrolysis libraries are applied to speed up substance identification. Using specialized evaluation software for pyrolysis GS-MS data, a fast and reliable comparison of the full chromatogram can be achieved. Since GC-MS is used as separation technique, the method is limited to volatile substances upon desorption and after pyrolysis of the sample. The method can be applied for quick substance screening in market control surveys since it requires no sample preparation steps.
Schreiver et al 2019 ChemStation_Library_Pigments_Polymers.L
This library contains spectra of specific pigment pyrolysis products that are not yet included in standard GC-MS libraries. Most decomposition products are unknown. Select this library (file format “.L”) in the GC-MS Software Enhanced ChemStation (Agilent Technologies, Waldbronn, Germany) as first choice. When hits have a probability below 80%, use NIST/EPA/NIH Mass Spectral Library (EI) mainlib as second choice library. The files are specific for the corresponding software but may be converted into other file types.
Schreiver et al 2019 ChemStation_Library_AMS_Pigments_Polymers.L
This library contains average mass spectra (AMS) of specific pigment pyrolysis GC-MS runs. Select this library (file format “.L”) in the GC-MS Software Enhanced ChemStation (Agilent Technologies, Waldbronn, Germany) for fast screening for pigment identities. Create an AMS of the unknown pyrogram and start the search.
The files are specific for the corresponding software but may be converted into other file types.
Schreiver et al 2019 MSChromSearch_Library_Pigments_Polymere
These data files are readily converted pyrograms of pigments for the specialized pyrogram search software (MSChromSearch, Axel Semrau GmbH & Co. KG, Sprockhövel, Germany). All pigments were pyrolyzed at 800°C. Double entries relate to different purity grades, manufacturers or repetitions at different time points.
To speed up the search, only 2-3 spectra of the pigments should be used (advanced search options). Load the file “Pigment_search_spectra.spf“. This contains 2-3 characteristic spectra for all pigments already included in the library.
Schreiver et al 2019 Pigment_pyrograms_elu_files
These data files are pyrograms of different pigments at 800°C. Double entries relate to different purity grades, manufacturers or repetitions at different time points. The Amdis .elu file format can be opened with open source software such as OpenChrom (Lablicate GmBH & Scientific community). However, the software does not allow pyrogram similarity searches (see data file "MSChromSearch_Library_Pigments_Polymers").
Schreiver et al 2019 ChemStation_Library_AMS_Pigments_Polymers
This library contains average mass spectra (AMS) of specific pigment pyrolysis GC-MS runs.
The file format “.MSP” can be opened with open source software such as OpenChrom (Lablicate GmBH & Scientific community).
Schreiver et al 2019 ChemStation_Library_Pigments_Polymers
This library contains spectra of specific pigment pyrolysis products that are not yet included in standard GC-MS libraries. Most decomposition products are unknown. The file format “.MSP” can be opened with open source software such as OpenChrom (Lablicate GmBH & Scientific community).
