Organochlorine pesticide residues in bovine milk from organic farms in Chiapas, Mexico.

Thirty six samples of bovine milk were collected from Chiapas State, Mexico between January 2011 and December 2011 with the intention of identifying and quantifying organochlorine pesticide residues in organic farms. The analyses were done using gas chromatography with an electron capture detector (Ni(63)). In general the values found in raw milk were lower than the permissible limit proposed by FAO/WHO/Codex Alimentarius 2006. Average concentrations for alpha + beta HCH were 3.62 ng/g, gamma HCH 0.34 ng/g, heptachlor + epoxide 0.67 ng/g, DDT and isomers 1.53 ng/g, aldrin + dieldrin 0.77 ng/g, and endrin 0.66 ng/g (only present in samples from farm 2). The organic milk from Chiapas has shown low concentrations of pesticide residues in recent years and satisfies international and national regulations for commercialization.