The Determination of Low Levels of Benzene, Toluene, Ethylbenzene, Xylenes and Styrene in Olive Oil Using a Turbomatrix HS and a Clarus SQ 8 GC/MS

Significance of the topic

The accurate determination of trace aromatic hydrocarbons (benzene, toluene, ethylbenzene, xylenes and styrene – BTEXS) in olive oil is critical for food safety and regulatory compliance. Environmental pollution can introduce these volatile contaminants into olive orchards, leading to human exposure through dietary oils. An efficient, sensitive and robust analytical workflow is therefore essential in quality control laboratories and research settings.

Objectives and Study Overview

This study demonstrates a streamlined headspace GC/MS method capable of quantifying BTEXS in olive oil at sub-ppb levels. The goals were to develop a simple sample preparation protocol, optimize chromatographic and mass spectrometric conditions, and validate performance through calibration, precision and detection limit assessments. A final application to commercial olive oil samples illustrates practical utility.

Methodology and Instrumentation

Methodology

• Sample Preparation: 10.00 g of olive oil weighed directly into a 22 mL headspace vial and hermetically sealed.
• Headspace Equilibration: 90 °C for 20 min, with transfer line at 140 °C and needle at 130 °C.
• Chromatography: PerkinElmer Clarus 680 GC equipped with a 30 m × 0.25 mm × 1.0 µm Elite-Wax column; oven ramp 35 °C (1 min) to 130 °C at 10 °C/min.
• Detection: Clarus SQ 8 MS operated in mixed single-ion/full-scan (SIFI) mode, scan range 35–350 Da, with selective ion recording to enhance sensitivity.

Main Results and Discussion

Calibration using method of standard addition yielded excellent linearity (r2 ≥ 0.9986) across 4.4–87.8 ng/g. Quantitative precision (n=10) showed relative standard deviations of 1.7–3.8 %. Predicted limits of detection ranged from 0.12 to 0.26 ng/g, outperforming typical 5 ng/g requirements. Analysis of seven supermarket olive oils revealed BTEXS levels from below detection to 126 ng/g, demonstrating method robustness with real samples.

Benefits and Practical Applications

This automated headspace GC/MS approach offers:

• Minimal sample preparation without solvent extraction or pre-concentration traps.
• Rapid analysis cycle (10.5 min run, 3.5 min equilibration).
• High sensitivity for regulatory monitoring and research.

Future Trends and Possibilities

Emerging opportunities include integration with high-throughput platforms, coupling to advanced data-processing algorithms for isomer discrimination, and extension to other edible oils and complex food matrices. Further miniaturization and ambient sampling techniques could streamline on-site testing.

Conclusion

The PerkinElmer Turbomatrix HS coupled to Clarus SQ 8 GC/MS provides a powerful, reliable solution for trace BTEXS analysis in olive oil. Its simplicity, sensitivity and speed make it well suited for routine quality control and research in food safety laboratories.

References

No external literature references were provided in the source document.