Imidacloprid Residues in Farm Gate Tomatoes (Solanum lycoperscicum) of Kimira-Oluch Smallholder Farm Improvement Project, Kenya

Abstract

Aims: Imidacloprid residues in farm gate tomatoes from Kimira-Oluch Smallholder Farm Improvement Project (KOSFIP) in Homa Bay County, Kenya were determined to evaluate compliance with Codex and EU residue limits. Study Design: Although there were several non-registered tomato farmers in KOSFIP, samples were obtained from 30 out of the registered 34 commercial tomatoes farmers using cross-sectional survey design and simple random sampling method. Methodology: QuEChERS method for extraction followed by LC-MS/MS was used to determine the concentrations. The levels were compared with the maximum residues limits (MRLS) of EU/Codex. Results: All samples had detectable imidacloprid residues levels ranging from 0.025 to 0.575 mg/kg. Box plot showed a right skewed distribution, but without outliers. Data were further subjected to standardized normal distribution statistics that revealed that 19 and 28 farms produced tomatoes that satisfied EU and Codex MRL limits respectively. When the general use of imidacloprid was assumed to be uniform among all KOSFIP farms including unregistered farms, 62.9% and 92.92%, were within EU and Codex MRL limits, respectively. Most farmers used GAPs recommended for tomatoes production, although there were 11 and 2 farms with tomatoes whose residues exceeded the EU and Codex limits respectively. Conclusion: Some famers did not observe GAPs, resulting into residue levels above the EU and Codex limits. Therefore, strengthening extension services, regular training and surveillance is essential to achieve full compliance to safeguard consumer safety.