Levels of organochlorine pesticides in onion and tomato samples from selected towns of Jimma Zone, Ethiopia.

This study aimed to determine residues of organochlorine pesticides (OCPs) in tomato and onion samples collected from selected markets in the Jimma zone. A QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method was used for sample preparation followed by gas chromatography-mass spectrometry (GC-MS) for OCPs analysis. The method used showed wide linear ranges from 5-50 μg/L for all eight pesticides, with R values ≥ 0.

Vortex-assisted dispersive micro-solid-phase extraction using silica-supported FeO-modified khat (atha edulis) biochar nanocomposite followed by GC-MS for the determination of organochlorine pesticides in juice samples.

In this paper, dispersive micro-solid phase extraction technique was developed for the purpose of extracting and preconcentrating organochlorine pesticide residues in juice samples before their separation and quantitative analysis by gas chromatography-mass spectrometry. A sorbent composed of a silica-supported FeO-modified khat leftover biochar nanocomposite (SiO-FeO-KLBNC) was implemented in the process. To improve the dispersion of the sorbent in the solution, vortex mixer was employed.