Determination of Volatile Organic Compounds (VOCs) in Potable Water Using Solid Phase Micro Extraction-Gas Chromatography (SPME-GC)

This study is aimed at detection and estimation of five Volatile Organic Compounds (carbon tetrachloride, tetrachloroethylene, 1,2-dichloroethane, 1,1,1-trichloroethane and 1,2,3-trichlorobenzene) by gas chromatography (GC). These compounds pose a risk to human health as well as environment. As the conventional sample extraction methods are laborious and tiresome involving frequent handling with solvents; solid phase micro extraction (SPME) technique was employed which is robust and cost-effective method of sample extraction with minimal exposure and handling of solvents. Sample extraction time was optimized as a first step by executing replicate analysis over 1, 5, 10 and 15 min while keeping certain other parameters constant; electron capture detector (ECD) was employed for the detection of analytes. As a second step, reproducibility of SPME fiber was verified by running replica; relative standard deviation was ranging from 3.5 to 19.3 %. Drinking water samples collected from selected gas and petrol stations were then analyzed as an application of the SPME-GC-ECD method. A total of 5 out of 27 sites were found to be contaminated with the compounds of concern mentioned above; two of them (1,2-dichloroethane, 1,1,1-trichlorobenzene) showed contamination above US-EPA's prescribed limits.