Trace Organics Determination in Potable Water

Abstract

Volatile organic compounds are an important parameter to be monitored for maintaining drinking water quality. They are important because of their carcinogenic potential. VOCs occur in numerous products including fuels, solvents, paints, adhesives, deodorants, and refrigerants. VOCs can infiltrate into the environment when they are being manufactured, stored and handled. They can enter both surface and ground water supplies and stay for a long time. There are several VOCs identified and studied in literature. In this study however, five VOCs were selected; the compounds chosen included Carbon tetrachloride, Tetrachloroethylene, 1,2-Dichloroethane, Trichloroethane and 1,2,3-Trichlorobenzene. The sampling points were the gas and petrol stations of the twin cities of Rawalpindi/lslamabad. The sites selected were specific because the groundwater in those areas is highly prone to contamination as per initial baseline survey and discussion with agencies such as CDA, RDA and WASA. Sampling was done for pH, temperature, conductivity, turbidity, Total Dissolved Solids, chlorides, sulfates, nitrates and Total Organic Carbon of the samples in sampling bottles and for VOCs analysis in special 40 mL vials. GC-ECD (Gas Chromatography/Electron Capture Detector) analysis was used for the estimation of selected VOCs. Solid phase microextraction (SPME) technique was used in this study. The fiber used was Carboxen/Polydimethylsiloxane