The influence of milk fat, temperature and time of storage on organochlorine pesticides in cow's milk

Persistent organic pollutants (POPs) are organic compounds that resist photolytic, biological and chemical degradation. Organochlorine pesticides (OCPs) are being extensively used in tropical countries in malaria control programs and against livestock ectoparasites and agricultural pests. They contain carbon, hydrogen and chlorine. Cow milk accumulates residues of these pesticides when they eat contaminated food, by inhaling contaminated air and by absorbing of pesticides sprayed on the skin of lactating cows. The research of seven OCPs is performed in raw cow's milk taken from Pelagonia from 10 individual farms. Tasted dairy fat is important for the quality of milk and the presence of OCPs that are soluble in fat milk. Different temperatures were applied in order to investigate influence of temperature on the presence of OCPs. According to investigations fat ranges from 3.75 - 3.9%, whereas the solubility and the presence of OCPs is differrent and ranges from 0-2%, with the exception of DDT which may be encountered and to 6% at a temperature of 71-74°C. Examined OCPs in milk kept for 6 days in the refrigerator until it's spoiling, DDT and then the most abundant and least aldrin. The determination was done by Gas chromatograph from "Agilent Technologies’’, and the degree of correlation has been demonstrated high accuracy of the method and absorption of pesticides sprayed on the skin of lactating cows. Most chlorinated insecticides are relatively resistant to processing techniques used for milk and dairy products. Once residues get into milk they are stable and difficult to remove; therefore, the best policy is to prevent their entrance into milk by proper and careful management of the dairy cow. In this paper the research is carried out by qualitative and quantitative determination of milk serum which commonly used non ionized organochlorine insecticides in milk.