An extractant having a strong affinity for palladium, bis(2,4,4-trimethylpentyl) monothiophosphinic acid (Cyanex 302), was enclosed into microcapsules by mixing with a biopolymer, calcium alginate gel polymer. The uptake of Pd2+ and other metal ions in the microcapsules was investigated; a relatively large distribution coefficient of Pd2+, K-d,K-Pd, of above 10(3) cm(3)/g was obtained around 0.1 M HNO3, and there was a large difference in K-d value between Pd2+ and other metal ions. The uptake of Pd2+ On microcapsules followed a Langmuir-type uptake isotherm. The microcapsules were packed into a column and then a separation of Pd2+ was performed.