Determination of bisphenol a traces in water samples from the Vrbas river and its tributaries, Bosnia and Herzegovina

The bisphenol A (BPA) concentration was determined in 12 surface water samples of the Vrbas River and its five tributaries. The samples were taken in the area that belongs to the city of Banja Luka (Bosnia and Herzegovina). BPA was isolated using micro liquid-liquid extraction followed by derivatization and gas chromatography-mass spectrometry analysis (GC-MS). Silylation was used as a derivatization method to increase volatility and allow GC-MS determination of BPA. The limits of detection (LOD) and quantification (LOQ), obtained by validating the procedure, were determined at 4 and 10 ng L-1, respectively. The concentrations of BPA were ranged between 33 and 354 ng L-1, and all were above the LOQ value. The lowest amount of BPA was found in the sample collected in the river Vrbas near Svrakava estuary upstream from the city of Banja Luka. The highest concentration of BPA was recorded at the confluence of the Crkvena and Vrbas rivers, which is located in the city center. This study shows that population and human activity could affect the level of BPA in the enviro.