Analysis of buffalo liver samples for the presence of chlorpyrifos residues by using high performance liquid chromatography

Food safety is of great importance to all involved in the food chain. The problem of pesticide residues is one of the concerns for the consumers. In the present study, 254 buffalo liver tissue samples were collected from 4 slaughterhouses and analyzed both qualitatively and quantitatively for the presence of chlorpyrifos residues. The samples were processed by extraction with acetonitrile followed by sonication and liquid-liquid partition. The extracts were cleaned up by performing alumina column chromatography. Chlorpyrifos residues in the samples were detected and quantified by employing high performance liquid chromatography. High performance liquid chromatography (HPLC) was performed by using the isocratic mobile phase, consisting of acetonitrile and water at a ratio of 67: 33 with a flow rate of 1 mL/min and a run time of 18 min. The detection wavelength was set at 202 nm with 360 nm as the reference wavelength. Chlorpyrifos residues were detected in 9.05% of the samples. Of these, only 0.78% of the liver samples were found to exceed the Codex maximum residue limit (MRL) for chlorpyrifos.