Quantitative structure activity relationship and risk analysis of some pesticides in the goat milk

The detection and quantification of different pesticides in the goat milk samples collected from different localities offaisalabad, pakistan was performed by hplc using solid phase microextraction. the analysis showed that about 50%milk samples were contaminated with pesticides. the mean±sem levels (ppm) of cyhalothrin, endosulfan, chlorpyrifosand cypermethrin were 0.34±0.007, 0.063±0.002, 0.034±0.002 and 0.092±0.002, respectively; whereas, methyl parathionwas not detected in any of the analyzed samples. quantitative structure activity relationship (qsar) models weresuggested to predict the residues of unknown pesticides in the goat milk using their known physicochemicalcharacteristics including molecular weight (mw), melting point (mp), and log octanol to water partition coefficient (ko/w)in relation to the characteristics such as ph, % fat, specific gravity and refractive index of goat milk. the analysis revealedgood correlation coefficient (r2 = 0.985) for goat qsar model. the coefficients for ko/w and refractive index for thestudied pesticides were higher in goat milk. this suggests that these are better determinants for pesticide residueprediction in the milk of these animals. based upon the determined pesticide residues and their provisional tolerable dailyintakes, risk analysis was also conducted which showed that daily intake levels of pesticide residues including cyhalothrin,chlorpyrifos and cypermethrin in present study are 2.68, 5.19 and 2.71 times higher, respectively in the goat milk. thisintake of pesticide contaminated milk might pose health hazards to humans in this locality.