Quantification of Contact Allergens in Personal Care Products with GC and Full Mass Range TOFMS

Significance of the Topic

Certain fragrances and ingredients in personal care products can trigger contact allergies and irritation in sensitive consumers. Regulatory frameworks such as the European Cosmetics Directive mandate reporting of 26 specified contact allergens above threshold levels. Reliable analytical methods are essential for screening, quantification, and compliance.

Objectives and Study Overview

This study evaluates the advantages of using full mass range time-of-flight mass spectrometry (TOFMS) coupled with gas chromatography (GC) for quantifying regulated contact allergens in complex cosmetic matrices. It compares targeted SIM approaches to comprehensive TOFMS acquisition and demonstrates automated calibration and deconvolution capabilities.

Methodology and Instrumentation

A set of allergen calibration standards (10 ppb–100 ppm) was prepared by serial dilution in isooctane. A leave-on perfume sample was diluted 100× prior to analysis.

• Gas Chromatograph: Agilent 7890 with MPS2 autosampler, 1 µL splitless injection at 250 °C
• Column: Rxi-5ms, 30 m × 0.25 mm i.d., 0.25 µm film
• Carrier Gas: Helium at 1.4 mL/min (constant flow)
• Oven Program: 40 °C (2 min) ramped to 280 °C at 10 °C/min, hold 5 min
• Transfer Line Temperature: 280 °C
• Mass Spectrometer: LECO Pegasus HT TOFMS, ion source 250 °C
• Acquisition: Full mass range 33–500 m/z at 15 spectra/s

Main Results and Discussion

All 26 regulated allergens were detected and identified using automated peak finding. Calibration curves for compounds such as geraniol exhibited excellent linearity (R² > 0.99) over four orders of magnitude. Full mass range data enabled recognition of coeluting matrix interferences that share diagnostic m/z values, which would skew quantification in a SIM‐only approach. Deconvolution algorithms isolated pure spectra of target analytes and interferences, allowing selection of unique m/z channels (e.g., m/z 123, 84 for geraniol) and accurate quantitation.

Benefits and Practical Applications

• Enhanced specificity through full mass range acquisition and deconvolution
• Automated calibration and retrospective data interrogation without reinjection
• Improved accuracy in regulated allergen quantification within complex formulations
• Streamlined compliance reporting for cosmetic and personal care manufacturers

Future Trends and Applications

Advances in high-resolution TOFMS and automated data processing will further improve detection limits and throughput. Integration with robotic sample preparation and machine-learning algorithms could enable real-time allergen monitoring and broader screening of emerging sensitizers in personal care products.

Conclusion

GC-TOFMS with full mass range acquisition on the Pegasus HT provides robust, accurate, and efficient quantification of regulated contact allergens in personal care products. The combination of high speed, sensitivity, and deconvolution ensures reliable results and supports regulatory compliance without repetitive analyses.