Automated fatty acid profiling of raw algae’s by THM-GC-MS

Importance of the topic

The widespread use of cosmetic and personal care products has led to increased concern over contact allergens in fragrances. Approximately 1–2% of consumers exhibit sensitivity to specific fragrance compounds. In response, the EU established strict threshold limits of 0.01% for rinse-off and 0.001% for leave-on products. Accurate quantification of these allergens is essential for regulatory compliance and consumer safety.

Objectives and overview of the study

This application note presents a gas chromatography–mass spectrometry (GC/MS) method employing a programmable temperature vaporizing (PTV) injector (OPTIC 3) to quantify common fragrance allergens in cosmetics. The study evaluates method performance using standard mixtures and real-world products, including creams, body oils, cleaning products, and shower gels.

Methodology and instrumentation

• Sample preparation: Three standard mixtures of allergens at 10, 40, and 100 ng/µL (1 µL injection) and eight raw cosmetic samples diluted 1:10 with methanol.
• Injection system: OPTIC 3 PTV injector with DMI liner (L100011) and 5 °C/s temperature ramp control.
• GC/MS setup: Shimadzu QP2010 GC-MS with InertCap 5 MS/Sil column (30 m × 0.25 mm, 0.5 µm film). Carrier gas flow set to 1.0 mL/min; split flow 100 mL/min.
• Oven program: Start at 35 °C (3 min), ramp to 250 °C at 10 °C/min, hold 5 min.
• MS acquisition: Full scan from m/z 35–350, scan time 0.5 s, from 3 min to 29.5 min.

Key results and discussion

• Retention times for alcohols, aldehydes, ketones, and esters ranged from 12.2 to 26.1 min, demonstrating clear separation.
• Standards exhibited linear responses across the tested concentration range with RSDs below 10%.
• Analysis of a cream-based sample identified and quantified eleven allergens with concentrations between 1.07 and 67.06 µg/mL, well below regulatory limits.
• High-boiling residues remained in the injector liner, reducing matrix interference and preserving column performance.

Benefits and practical applications

• Minimal sample preparation (simple dilution) accelerates throughput and reduces labor.
• Reproducible performance (RSDs < 10%) supports routine quality control in cosmetic manufacturing.
• Meets EU requirements for allergen quantification in leave-on and rinse-off products, ensuring consumer safety.

Future trends and applications

As global regulations on fragrance allergens tighten, demand will grow for automated, high-throughput GC/MS solutions. Advances such as high-resolution MS, enhanced data processing algorithms, and integrated sample handling will further streamline quantification and expand the range of detectable allergens.

Conclusion

The OPTIC 3 PTV-GC/MS method delivers robust, sensitive quantification of fragrance allergens in cosmetics with minimal sample preparation. Its accuracy and reproducibility align with EU regulatory thresholds, making it an effective tool for compliance testing and quality assurance.

Reference

Regulation (EC) No. 648/2004 on detergents and Annex III on fragrance allergens.