Citronella Oil on Rxi-5Sil MS

Significance of the Topic

Citronella oil is widely applied in perfumery, flavoring and as a natural repellent. Comprehensive chemical profiling ensures consistency, authenticity and efficacy in industrial, pharmaceutical and cosmetic contexts.

Objectives and Study Overview

This application note describes the development of a gas chromatography–mass spectrometry (GC–MS) method for detailed constituent analysis of citronella oil using an Rxi-5Sil MS column and NIST library matching.

Methodology and Instrumentation

• Column: Rxi-5Sil MS, 30 m × 0.25 mm i.d., 0.25 µm film thickness
• Sample Preparation: 5 % citronella oil in acetone
• Injection: 1 µL split (100:1) via Topaz 4.0 mm ID inlet liner with wool, injector at 250 °C
• Oven Program: Ramp from 100 °C to 300 °C at 11 °C/min, hold 10 min
• Carrier Gas: Helium, constant flow of 1.31 mL/min
• Detector: Agilent 7890A GC coupled to 5975C MSD (quadrupole), EI mode
• Scan Parameters: 35–500 amu at 5 scans/sec, transfer line 300 °C, source 230 °C, quadrupole 150 °C
• Identification: NIST MS EI spectra library (2005)

Major Results and Discussion

The chromatogram resolved 28 components. Early-eluting monoterpenes (α-pinene, D-limonene, linalool, citronellal, isopulegol isomers, α-terpineol, β-citronellol, Z- and E-citral, geraniol) were observed between 2.06 and 4.46 min. Oxygenated esters and phenols (citronellyl propionate, eugenol, geranyl acetate) appeared at 5.26–5.56 min. Late-eluting sesquiterpene hydrocarbons and alcohols (caryophyllenes, α-amorphene, germacrene D, α-muurolene, cadinenes, elemol, eudesmols) were detected from 5.82 to 8.66 min. Baseline separation allowed clear differentiation of isomeric species.

Benefits and Practical Applications

• Fast, reproducible profiling for quality control of essential oils
• Accurate identification of fragrance and bioactive compounds
• Support for authentication and batch-to-batch consistency studies

Future Trends and Potential Applications

Advances may include high-resolution MS for exact mass determination, chemometric tools for geographic or botanical origin classification, and integration with preparative systems for isolation of target bioactive constituents.

Conclusion

The GC–MS method on an Rxi-5Sil MS column offers a robust, efficient platform for comprehensive chemical characterization of citronella oil, facilitating quality assurance and research in fragrance, flavor and repellent industries.

References

• Restek Corporation. Citronella Oil on Rxi-5Sil MS. 2019.