Potential Allergens in Aromatherapy Oils by GC/MS Using an Agilent J&W DB-XLB Capillary Column

Significance of the topic

Aromatherapy oils are widely used in massage and wellness applications, but they inherently contain volatile flavor and fragrance compounds that can induce allergic reactions. The European Union regulates 26 allergens in cosmetics and fragrances, 24 of which are amenable to gas chromatography/mass spectrometry (GC/MS) analysis. Establishing a reliable, sensitive, and rapid method for detecting these potential allergens in essential oils is essential for ensuring user safety, accurate labeling, and regulatory compliance.

Objectives and study overview

This application study aimed to demonstrate the capability of a single‐quadrupole GC/MS system, coupled with an Agilent J&W DB‐XLB capillary column, to separate, detect, and identify all 24 EU‐listed GC/MS‐amenable flavor and fragrance allergens in aromatherapy oils. Representative essential oils (ylang ylang, lavender, and eucalyptus) were analyzed to assess the method’s performance in realistic sample matrices.

Methodology and instrumentation

The analysis employed an Agilent 7890A GC System and 5975C MSD with a triple‐axis detector. The column was an Agilent J&W DB‐XLB (30 m × 0.25 mm × 0.25 µm). Helium carrier gas was maintained at fixed pressure, and injections were made in split mode (50:1) with a 1 µL injection volume. The oven temperature program ranged from 50 °C to 280 °C with multiple ramps to resolve complex mixtures. A combined standard solution of 24 allergens at 40 ng/µL (40 ppm) and an internal standard (1,4-dibromobenzene) were prepared in acetonitrile. Essential oil samples were diluted 1:20 in acetone to simulate typical 3–5% dropwise application concentrations.

Main results and discussion

The DB‐XLB column delivered excellent resolution and peak shape for all 24 target allergens at a loading of 0.8 ng/component on-column. Isomeric pairs such as citral (neral/geranial), lyral, and farnesol were fully resolved. In ylang ylang oil, four EU allergens (linalool, cinnamyl acetate, benzyl benzoate, benzyl salicylate) were identified at levels exceeding the 10 ppm threshold by more than 100-fold. Lavender oil contained linalool at approximately 1000 ppm, while eucalyptus oil showed linalool at about 50 ppm. The inclusion of the dibromobenzene internal standard in every chromatogram facilitated peak assignment and relative quantitation across standards and samples.

Benefits and practical applications of the method

• Single‐run, single‐column GC/MS approach minimizes method complexity and run time.
• DB‐XLB stationary phase provides mid‐polarity selectivity, enhancing resolution of active alcohols and aldehydes prone to poor chromatographic behavior.
• Sensitivity down to single‐digit ppm levels supports compliance with EU rinse‐off and leave‐on limits (10–100 ppm).
• Robust performance in complex natural oil matrices simplifies routine QA/QC workflows in fragrance, cosmetic, and aromatherapy product testing.

Future trends and opportunities for application

Advances in column technology and GC/MS instrumentation continue to expand analytical possibilities. Two‐dimensional GC and low‐thermal‐mass devices offer further separation power for highly complex mixtures. Deconvolution software can aid identification in coeluting regions. Liquid chromatography/mass spectrometry (LC/MS) methods complement GC/MS for nonvolatile allergens such as oak moss. Integration of automated sample preparation and data processing pipelines will accelerate high‐throughput screening and support evolving regulatory requirements globally.

Conclusion

The single quad GC/MS method using an Agilent J&W DB‐XLB column reliably detects and identifies all 24 EU GC/MS‐amenable flavor and fragrance allergens in essential oils at regulatory levels. Excellent chromatographic resolution and sensitivity were achieved in both standard and diluted oil matrices, demonstrating the approach’s applicability for routine safety testing in aromatherapy, cosmetics, and fragrance industries.

Reference

1. EU Directive 2003/15/EC, Official Journal of the European Union, L66 26, 11.3.2003.
2. Clark S., Essential Chemistry for Aromatherapy, 2nd Ed., Elsevier, 2009, Ch.8.
3. Luan W., Sandy C., Szelewski M., Determination of Allergens in Fragrance Products Using Deconvolution Reporting Software, Agilent Technol. 5989-8723EN, 2008.
4. David F., Klee M.S., Analysis of Suspected Flavor and Fragrance Allergens Using Two-Dimensional GC, Agilent Technol. 5990-3576EN, 2009.
5. Smith D., Lynam K., GC/MS Identification of Flavor and Fragrance Allergens in Snack Foods, Agilent Technol. 5990-4784EN, 2009.