Analysis of contaminated milk with organochlorine pesticide residues using gas chromatography

Abstract

Milk and milk products are considered to have tremendous nutritional values as they contain a good proportion of protein, fats, and important minerals. However, the nutritional value of the milk produced in Pakistan is not up to the mark as extensive use of pesticides on crops resulted in contamination of milk. Consumption of contaminated food such as milk, meat, fish, eggs can induce increased proportion of organochlorine pesticides in the body. The purpose of this study is to determine organochlorine pesticide residues in milk and their toxicity level by Maximum Residues Level (MRL) values. In the current study, organochlorines such as Dichlorodiphenyltrichloroethane (DDT), Dichlorodiphenyldichloroethane (DDE), Dieldrin, Gamma-hexachlorocyclohexane (Ɣ-HCH) also known as Lindane, α-Endosulphan, β-Endosulphan and Endosulphan sulphate were detected with the help of gas chromatograph equipped with electron detector. These pesticides were confirmed by using gas chromatography-mass spectrometry (GC-MS). Analysis of variance is applied (ANOVA) to determine variations of pesticides in all milk samples. Analysis showed non-significant results (p > 0.05) with large variation among all milk samples regarding pesticide residues. The mean values of DDT, DDE were found to be below the MRL value. The mean values of Dieldrin, Ɣ-HCH were also below MRL value. On the other hand mean values of α-Endosulphan, β-Endosulphan, and Endosulphan sulphate were slightly higher than MRL in few milk points. The present study showed large variations of pesticides residues present in milk samples.

Keywords

• Milk
• Organochlorine pesticides
• Gas chromatography mass spectrometry
• DDT
• DDE
• Ɣ-HCH
• α-Endosulphan
• β-Endosulphan
• Endosulphan sulphate