Bis(2,4.4-trimethylpentyl)dithiophosphinic acid (Cvanex 301) was used as a highly efficient carrier for the transport of bismuth ions through a carbon tetrachloride bulk liquid membrane. Using 5 M HNO3 in the receivng phase, the amount of bismuth transported across the liquid membrane. after 2 h, was 94 +/- 2%. The selectivity and efficiency of bismuth transport from acidic Solution containing a competing ion was investigated. Results showed that the interfering effect of the various ions tested was negligible. (C) 2002 Elsevier Science B.V. All rights reserved.