Determination of Pesticide Residue in Brinjal Sample Using HPTLC and Developing a Cost-Effective Method Alternative to HPLC

Abstract

Two analytical techniques HPLC (high performance liquid chromatography) and HPTLC (high performance thin layer chromatography) were validated to reveal the quality and quantity of pesticide residues (organophosphorus, organochlorine, and pyrethroids) in brinjal samples collected from a local market of Faisalabad. The HPTLC methods showed linear behavior for standard samples and residue was in the range of 1–130 ng. The organochlorine (α-endosulfan) contaminates the samples at 4, 5, 9, and 10 weeks, and detected quantity was less than MRL (minimum residue level) of the FAO (Food and Agriculture Organization of United Nations), i.e., 0.5 mg·kg−1. The organophosphorus pesticide (chlorpyriphos, methamidophos, monocrotophos, dichlorvos, carbosulfan, profenophos, and dimethoate) residue contaminated the samples and violated the MRL limit. Pyrethroids (deltamethrin, β-cyhalothrin, and cypermethrin) were present at appreciable levels, in samples of 1, 3, 4, 6, 8, and 9 weeks. The concentration of β-cyhalothrin (0.25 mg·kg−1) and cypermethrin (0.205 mg·kg−1) was significantly higher than that of all detected pesticides. The carbosulfan and deltamethrin contaminated all 10-week samples. The HPLC analysis of samples was carried out to confirm the efficiency of HPTLC as cost-effective method. The concentration of α-endosulfan, chlorpyriphos, dimethoate, monocrotophos, profenophos, deltamethrin, and cypermethrin in brinjal samples through the HPTLC method showed similar residual concentration with HPLC analysis.