EXTRACTION OF ARSENIC(III) WITH MACROPOROUS RESIN IMPREGNATED WITH BIS(2-ETHYLHEXYL)AMMONIUM BIS(2-ETHYLHEXYL)DITHIOCARBAMATE

The extraction of arsenic(III) was investigated by using macroporous r esin impregnated with a newly synthesized hydrophobic extractant: bis( 2-ethylhexyl)ammonium bis(2-ethylhexyl)dithiocarbamate (BBDC). In a pr eliminary experiment on liquid-liquid extraction, arsenic(III) was fav orably extracted with BBDC in heptane from acidic to neutral solutions ; the distribution ratios with 0.01 mol dm(-3) BBDC were larger than 1 0(2.5) at pH 0-6. The batchwise extraction of arsenic(III) with the im pregnated resin was carried out. The distribution ratio was more than 10(3) in an acidic region, and sharply decreased above pH 8. The colle ction of a trace amount of arsenic(III) was performed by using the col umn packed with the impregnated resin as a stationary phase. Then arse nic(III) retained on the column was quantitatively eluted out with an alkaline solution.