Simultaneous Determination of Aromatic Amines in Tattoo Ink by Gas Chromatography–Electron Ionization (GC-EI)–Mass Spectrometry (MS) and Tandem MS (MS/MS)

Aromatic amines (AAs) are potent carcinogens found in tattoo inks that pose significant health risks. Precise quantitative analysis is essential for safety. In this study, we developed and validated a robust method for the simultaneous quantification of 21 regulated AAs using both gas chromatography–electron ionization (GC-EI)–mass spectrometry (MS) and tandem MS (MS/MS). After optimizing separation conditions, MS-based selected ion monitoring (SIM) and MS/MS-based multiple reaction monitoring (MRM) were evaluated. While both methods were largely sufficient to ensure compliance with international safety thresholds, the MRM-based approach exhibited superior detection capability with comparable analytical accuracy and precision, providing a more effective tool for trace-level hazardous compound analysis. The developed MRM method was applied to eight commercial tattoo inks, identifying five AAs in five products. Notably, o-toluidine, o-anisidine, and 3,3′-dichlorobenzidine significantly exceeded the regulatory limit (5.0 mg/kg), particularly in green and yellow inks. The dual-capability GC-MS platform—combining high-performance MRM quantification with robust spectral confirmation—ensures the high throughput and analytical confidence necessary for regulatory compliance and public health protection.