Today's Messages

The Chemistry Department is hosting a graduate student seminar on Thursday, December 4, during Bengal Pause (12:15–1:30 pm) in SAMC 151. Our speaker will be Hannah Bergner, a graduate student in the Forensic Science master’s program. Her presentation is titled:

“Detection and Quantification of Pesticide Residues Using GC-ECD and LC-MS/MS.”

An abstract of her talk is provided below.

 Abstract

Pesticides are widely used to regulate crop production, with their use dating back about 4,500 years to the Sumerians, who used sulfur to control insects and mites. Modern research has shown that many pesticides act as Persistent Organic Pollutants, allowing them to bioaccumulate in soil and in produce consumed by the public. Three major classes—organochlorines, pyrethroids, and organophosphates—are of particular concern due to their persistence, extensive use, and negative effects on the human nervous system. To detect and analyze pesticide residues, researchers commonly use GC-µECD and LC-MS/MS. GC-µECD is suited for volatile compounds; it vaporizes analytes and uses a radioactive isotope (e.g., Ni-63) to measure electron capture, which correlates with analyte concentration. LC-MS/MS is used for less volatile compounds; samples pass through a liquid chromatographic column, are ionized, fragmented, and detected based on mass-to-charge ratios. This seminar reviews recent studies in Ethiopia that used these methods to identify various pesticide residues—both banned and permitted—and assess their bioaccumulation in soil and vegetables, along with the implications for public exposure 

References

1. Belete, T. Y., & Feleke, H. T., LC‐MS/MS Triple Quadrupole Multiresidue Analysis of Pesticides from Soils of Vegetable Farms: A Report from Ethiopia, Applied and Environmental Soil Science, 2025, 4830881.
2. González-Curbelo, M. Á., Varela-Martínez, D. A., & Riaño-Herrera, D. A., Pesticide-Residue Analysis in Soils by the Quechers Method: A Review, Molecules, 2022, 27, 4323.
3. Radowan, A. A., Analytical Techniques for Determining Pesticide Residues in Food: A Comprehensive Review, International Journal of Materials Technology and Innovation, 2024, 4, 47.
4. Tesfaw, A., Zewge, B., Asrat, M., & Tadesse, B., Quantitative Analysis of Pesticides in Vegetables: A Study on Tomatoes and Onions from Ethiopian Farms, Measurement Food, 2025, 19, 10024.
5. Wahab, S., Muzammil, K., Nasir, N., Khan, M. S., Ahmad, M. F., Khalid, M., Ahmad, W., Dawria, A., Reddy, L. K. V., & Busayli, A. M., Advancement and New Trends in Analysis of Pesticide Residues in Food: A Comprehensive Review, Plants, 2022, 11, 1106.