Assessment of Dermally Bioaccessible Elements by Sweat-Simulated Extraction: Analytical Approach and Application to
Carmela Protano1, Arianna Antonucci1, Maria Luisa Astolfi2
1Department of Benessere, Salute e Sostenibilità Ambientale, Sapienza University of Rome, 00185 Rome, Italy.
Molecules (Basel, Switzerland)
|June 12, 2026
Summary
This study introduces artificial sweat extraction to measure soluble elements in tattoo inks, revealing color-dependent release trends. The method aids in assessing potentially bioaccessible elements for consumer safety under European REACH regulations.
Area of Science:
- Analytical Chemistry
- Environmental Science
- Materials Science
Background:
- Standardized methods for determining soluble elemental contaminants in tattoo inks are lacking.
- This hinders comparability of analytical results and exposure assessment under European REACH regulations.
- Assessing bioaccessible elements requires physiologically relevant extraction techniques.
Purpose of the Study:
- To apply artificial sweat extraction as a mild, physiologically relevant method for evaluating elements released from tattoo inks.
- To assess potentially bioaccessible elements in tattoo inks under simulated skin-contact conditions.
- To establish a transferable methodology for exposure-oriented risk assessment of tattoo inks.
Main Methods:
- Seventy-eight commercial tattoo inks were extracted using artificial sweat at 37°C for 1 hour.
- Inductively coupled plasma mass spectrometry (ICP-MS) was employed for elemental analysis.
- Method optimization included collision/reaction cell conditions, dilution, internal standard correction, and matrix-matched calibration to address interferences from artificial sweat.
Main Results:
- Artificial sweat extraction effectively evaluated elements released from tattoo inks, showing color-dependent trends for elements like Cu, Zn, Ba, Al, Ga, Si, Sr, and Zr.
- Optimization successfully mitigated matrix interferences from artificial sweat's high salt and chloride content, ensuring reliable quantification.
- Soluble Ba, Cu, and Zn levels were found to be below European Union regulatory limits.
Conclusions:
- Artificial sweat extraction provides a simple, transferable tool for the exposure-oriented assessment of potentially bioaccessible elements in tattoo inks.
- The methodology aids in understanding elemental release under sweat-simulated skin-contact conditions.
- While total digestion is crucial for full characterization, this method offers valuable insights into bioaccessibility relevant to consumer safety regulations.
