QuEChERS–GC–MS/MS Chromatographic Method for Organochlorine Pesticide Residue Analysis in Sesame Seeds

Researchers at Jinka University and the University of Gondar (Ethiopia) addressed the need for a more comprehensive approach to monitoring sesame seeds, aimed at improving both consumer safety assurance and market acceptance. To determine selected organochlorine pesticide (OCP) residues in the seeds, a quick, easy, cheap, efficient, rugged, and safe (QuECHERS) method followed by gas chromatography coupled with tandem mass spectrometry (GC–MS/MS) was used for the rapid separation and determination of 20 OCPs in sesame seeds. A paper based on their work was published in the Journal of Analytical Methods in Chemistry (1).

Sesame seeds (Sesamum indicum L.) are valued for their nutritional properties, including high levels of healthy fats, protein, vitamins, minerals, and dietary fibers, and are consumed either directly as seeds or processed into oil, making them a staple in many diets worldwide (2). In terms of global total sesame production, Ethiopia ranked ninth in global total sesame production for 2019, with an annual production of 262,654 metric tons (3).

The indiscriminate and repeated use of synthetic pesticides, however, can lead to the accumulation of toxic residues in agricultural produce, posing a serious threat to consumer health and the international market (4). OCPs are a class of synthetic chemicals widely used for agricultural pest control because of their effectiveness and low cost in most of the developing world (5). However, while OCPs are effective in controlling pests, their well-known potential for bioaccumulation poses significant risks to human and wildlife health, including endocrine disruption and carcinogenic effects (6).

For this study, acetonitrile in combination with 1% glacial acetic acid was used as an extraction solvent. Primary secondary amine, graphitized carbon black, and octadecylsilane in QuEChERS kit were used for d-SPE cleanup before GC–MS/MS analysis. The GC–MS/MS analysis was evaluated in terms of linearity, recovery, and precision. The researchers report that calibration curves were obtained for all analytes, and each displayed good linearity over the selected concentration range, with regression coefficients (r ²) ≥ 0.999. The recoveries for spiked analytes in sesame seed samples ranged from 93.58 to 115.81, with relative standard deviations (RSDs) lower than 1%. The limit of detection (LOD) and limit of quantification (LOQ) for all investigated pesticides were in the range of 0.05–0.88 μg/kg and from 0.16 to 2.93 μg/kg, respectively (1).

“The application of GC–MS/MS in the MRM mode for the rapid detection of 20 OCPs in sesame seeds demonstrates a significant advancement in analytical chemistry and food safety monitoring,” the authors write in their study (1). “The method provides several advantages, including reduced solvent usage, shorter preparation times, and the ability to handle multiple samples simultaneously. This is particularly beneficial for routine analysis in laboratories where throughput and efficiency are critical” (1).

“The combination of QuEChERS with GC–MS/MS in the MRM mode,” they continue, “allows for high specificity and sensitivity in detecting low concentrations of OCPs, which is essential given the potential health risks associated with pesticide residues in food products. The use of MRM mode enhances the analytical performance by enabling the simultaneous quantification of multiple target compounds with minimal interference from coeluting substances. This capability is crucial for ensuring compliance with regulatory limits and safeguarding consumer health. The method’s robustness and reliability further underscore its applicability in routine monitoring programs. Finally, this study highlights the effectiveness of integrating QuEChERS sample preparation with GC–MS/MS in the MRM mode for the rapid and accurate detection of OCPs in sesame seeds” (1).

In conclusion, the authors suggest that future studies might focus on extending this methodology to other food matrices and a wider range of contaminants, thereby enhancing global food safety surveillance systems (1).

Read More on Similar Topics

Gas Chromatographic Analysis of Fatty Acids in Butia Seed Oil Oleogels and Their Functional Performance in Cookies
Evaluating Erucic Acid in Mustard via GC-FID

References

1. Ago, K. A.; Tefera, M. Enhanced Detection of Organochlorine Pesticide Residues in Sesame Seeds (Sesamum indicum L.) Using Advanced GC-MS/MS Techniques. J. Anal. Methods Chem. 2026, 2026, 8312847. DOI: 10.1155/jamc/8312847
2. Wei, P.; Zhao, F.; Wang, Z. et al. Sesame (Sesamum indicum L.): A Comprehensive Review of Nutritional Value, Phytochemical Composition, Health Benefits, Development of Food, and Industrial Applications. Nutrients 2022, 14 (19), 4079. DOI: 10.3390/nu14194079
3. Teklu, D. H.; Shimelis, H.; Tesfaye, A. et al. Appraisal of the Sesame Production Opportunities and Constraints, and Farmer-Preferred Varieties and Traits, in Eastern and Southwestern Ethiopia. Sustainability 2021, 13 (20), 11202. DOI: 10.3390/su132011202
4. Negatu, B.; Dugassa, S.; Mekonnen, Y. Environmental and Health Risks of Pesticide Use in Ethiopia. J. Health Pollut. 2021, 11 (30), 210601. DOI: 10.5696/2156-9614-11.30.210601
5. Ajiboye, T. O.; Kuvarega, A. T.; Onwudiwe, D. C. Recent Strategies for Environmental Remediation of Organochlorine Pesticides. Appl. Sci. 2020, 10 (18), 6286.DOI: 10.3390/app10186286
6. Zaynab, M.; Fatima, M.; Sharif, Y. et al. Health and Environmental Effects of Silent Killers Organochlorine Pesticides and Polychlorinated Biphenyl. Journal of King Saud University-Science 2021, 33 (6), 101511. DOI: 10.1016/j.jksus.2021.101511