Determination of vapour pressure of permethrin technical pesticide using gas saturation method with gas chromatographic methodAuthor(s): Karri. Apparao, M.S. Surendra Babu, N. Krishna Rao, G. Kumarand Tentu. Nageswara Rao
The vapour pressure of permethrin technical was conducted using the gas saturation method based on the regulatory OPPTS 830.7950 and EECA.4 guidelines.According to this method the packed vapour saturator columns were connected to vapour pressure apparatus and the columns were exposed to different flowrates. The flow rateswere 20 (F1), 40 (F2) and 60 mL/min (F3). This set up was equilibrated at 40°C for whole night. After equilibration the nitrogen gas outlet from the column was connected to the trapping system. Nitrogen gas was continuously passed through each saturator column. The maintained flowrate and temperatureswere monitored during the study period. At the end of 10 days, the trapping agent was collected from the trapping system by eluting the glass columns using 100 mL of acetone. The collected eluate was concentrated using rotary vacuum evaporator to near dryness, and diluted to specific volume using acetone. The samples were analyzed by validated GC method. The vapour pressure of the test itempermethrin Technical was found to be 2.08 ï´10-6 Pa at 20ï°C and 6.58 ï´ 10-6 Pa at 40ï°C.