Detection and semiquantitative determination of bismuth(III) in water on immobilized and plasticized polyurethane foams with some chromogenic reagents

Polyurethane foams immobilizing 1,2-di-(2-fluorophenyl)-3-mercaptoformazan (F(2)H(2)Dz) and dithizone (H(2)Dz) have been used for the detection of bismuth(III) in water via batch, dynamic and pulsated column modes of extraction. The detection limits of bismuth(III) with the F(2)H(2)Dz- and H(2)Dz-immobilized foams were found to be 0.01 and 0.02 mu g ml(-1) respectively. Lower concentrations (less than or equal to 1 ppb) of bismuth(III) were also detected by employing dynamic and pulsated columns packed with plasticized tri-n-butylphosphate and F(2)H(2)Dz-immobilized reagent foams. The electronic spectra and partition coefficients of the reagents H(2)Dz and F(2)H(2)Dz and their bismuth(III) chelates in chloroform and in polyurethane foams have been determined. Bismuth (V) was also detected by the proposed procedure after prior reduction to bismuth(III) with sulphur dioxide at pH < 1. The effect of diverse ions on the detection of 1 mu g of bismuth(III) was critically investigated using F(2)H(2)Dz-immobilized foam. (C) 1997 Elsevier Science B.V.