The objective of this research to optimise the HPLC method was developed for quantitative determination of Pirimiphos-methyl. Chromatographic separation was achieved on a 250 x 4.6 mm i.d. reversed phase column Qualisil BDS 5u C18, Using deionized acetonitrile:water in the ratio of 85:15 v/v respectively as mobile phase. The eluent was monitored at 254 nm. A sharp peak was obtained for the Pirimiphos-methyl at 9.29 min. The UV Spectrophotometric method performed at 254 nm after full scan analysis using methanol as a solvent. The result revealed that both methods are suitable to carry out routine analysis of Pirimiphos methyl, However HPLC results showed high precise, accurate and sensitive than the UV Spectrophotometer. Hence HPLC method is suitable for trace analysis of Pirimiphos methyl in environmental samples.

The soil sample was collected from the paddy field of Sriperumbudur, Tamilnadu which is having a history of repeated pesticide applications. The isolation of efficient pesticide degrading bacteria was identified as Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis. The growth of the three pesticide degrading isolates was assessed in Minimal salt broth containing 25 ppm of pesticides. Two popularly used pesticides Metribuzin and Profenofos were selected for this study. Among the three bacterial isolates, the bacteria Bacillus subtilis utilized the pesticides effectively and showed maximum growth. The growth of the three pesticides degrading isolates Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis was assessed in Minimal salt broth containing 25 ppm of pesticides at different temperature levels (25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C & 55 °C) and pH levels (pH 4, pH 5, pH 6, pH 7 & pH 8) and carbon sources (Lactose, Dextrose, Fructose, Mannose & Galactose) and nitrogen sources Peptone, Yeast extract, Beef extract, Malt extract and Casein respectively. The maximum growth rate of bacteria was recorded at 35 °C and pH 6. The maximum growth of bacteria was in the presence of Dextrose followed by Fructose, Galactose and Mannose. The least growth was recorded in Lactose broth culture. The maximum growth of bacteria was in the presence of Malt extract followed by Peptone, Yeast extract and Casein. The least growth was recorded in Beef extract broth culture. The bacterial isolates showed maximum growth in the Minimal salt broth containing Profenofos followed by Metribuzin