Selective preconcentration and determination of tributyltin in fresh water by electrothermal atomic absorption spectrometry

摘要

A rapid and simple method for separation and determination of tributyltin (TBT) in mineral and tap water is described. The procedure is based on the selective retention of TBT by a chelating resin, Amberlite XAD-2 impregnated with tropolone. The addition of 0.8 sulfuric acid to the water sample leads to the retention of TBT by the resin while monobutyltin (MBT), dibutyltin (DBT) and inorganic tin remain in solution. TBT is eluted with methyl isobutyl ketone (MIBK) obtaining a preconcentration factor of 80. Tin concentration is determined by ETAAS using zirconium coated tubes. Multi injection and hot injection techniques are used in order to enhance the sensitivity of the method. A detection limit of 14.4 ng L~(-1) is achieved with recoveries near to 100. The procedure has been successfully applied to TBT determination in various fresh water samples.