Assessment of contamination by organochlorine pesticides in Solanum lycopersicum L. and Capsicum annuum L.: A market survey in Nigeria

Abstract

This study investigated the presence and levels of organochlorine pesticides (OCPs) (hexachlorobenzene (HCB), α‑, β‑, δ‑, and γ‑hexachlorohexane (HCH), dieldrin, dichloro-diphenyltrichloroethane (p,p’-DDT), dichloro-diphenyl-dichloroethylene (p,p’-DDE), dichloro-diphenyldichloroethane (p,p’-DDD) and trans-nonachlor) in Solanum lycopersicum and Capsicum annuum samples commercially sold in Nigeria. OCPs were detected in all the samples analysed using Hewlett-Packard (HP 6890) gas chromatograph equipped with electron capture detector (GC-ECD). In S. lycopersicum, the total residue concentrations of ΣHCH (0.140 mg/kg), ΣHCB (0.144 mg/kg), ΣDDT (0.572 mg/kg), Σdieldrin (0.073 mg/kg), and Σtrans-nonachlor (0.117 mg/kg) were found. In C. annuum, the total residue levels of HCH, HCB, DDT, dieldrin and trans-nonachlor measured were 7.220, 0.096, 0.275, 0.037 and 0.117 mg/kg respectively. The α‑HCH isomer was not detected in S. lycopersicum and p,p’-DDD found only in C. annuum samples. The OCPs levels were generally below the FAOs maximum residue limits except for HCH and trans-nonachlor. A pair-wise linear correlations among concentrations of OCPs in S. lycopersicum samples indicated statistically significant (P = 0.05) relations between δ‑HCH and dieldrin (r = -0.997, P = 0.047), dieldrin and HCB (r = 0.99, P = 0.043), p,p’-DDD and p,p’-DDT (r = 1.00, P = 0.006).

Key words: Organochlorine pesticides, Solanum lycopersicum, Capsicum annuum, vegetables, gas chromatography.