Chemistry Division, Atomic Energy Centre, GPO Box No. 164, Ramna, Dhaka-1000, Bangladesh
A rapid and reproducible method is described that employs solid phase extraction (SPE) using dichloromethane, followed by gas chromatograph-mass spectrometry for the determination of toxic toluene, xylene and cumene (TXC) from different lake water of Dhaka mega city of Bangladesh. The method was applied to detect and quantify TXC in water samples collected from surface and 30 cm depth of water. Fifty milliliters of pretreated methanol and filtered water samples were applied directly to a C18 SPE column. TXC were extracted with dichloromethane and the TXC concentration was obtained to be 2.34 to 52.12 ppm. The factors influencing SPE e.g., absorbent types, sample load volume, eluting solvent and temperature, were investigated. A cartridge containing a C18 absorbent and using solvent gave a better performance for the extraction of TXC
from the lake water samples. Average recoveries exceeding 90% could be achieved for toluene at 24oC with a 2.8% RSD.