Determination of normal saturated hydrocarbons in the Buriganga river water of Bangladesh by gas liquid chromatography

The concentrations of normal saturated hydrocarbons (C₁₀ - C₂₄) were determined in water at the stations of Postagolla, Sadarghat and Sowarighat of the Buriganga river, Bangladesh. Samples were collected from different water depths (5 and 25 cm) of the sampling stations. Hydrocarbons were extracted from these water samples (500 ml) into 70 ml hexane which were further preconcentrated by evaporation to a volume of 10 ml solution. Constituents of hydrocarbons were analyzed qualitatively and quantitatively by gas liquid chromatography (GLC) using flame ionization detection (FID). Different concentrations of hydrocarbon constituents were obtained in river water at the various sampling stations. Irrespective of the locations and depths of the sampled water, few lower hydrocarbons (C₁₀ - C₁₃) were detected, but higher hydrocarbons (C₁₄ - C₂₄) were found to occur. However, the average concentrations of the components e.g., C₂₂ and C₂₄ at Postagolla, C₁₆ and C₂₂ at Sadarghat and C₁₆ at Sowarighat (5 cm depth) were determined to be higher than the other hydrocarbons. The concentrations of individual constituents were found in the range of 1.04 to 6135 ppb. This method could permit the analysis of water for hydrocarbons with a detection limit as low as 1.04 ppb level.