高含量砷（Ⅲ）与砷（Ⅴ）的萃取分离法研究

Investigation on the Method of Extraction-Separation fr High Contents of As(Ⅲ)and As(V)

本文对高含量Ａｓ（Ⅲ、Ｖ）的萃取分离方法进行了研究。指出，在≥１０．５ｍｏｌ／ＬＨＣｌ介质中用苯萃取，可使５０ｍｇＡｓ（Ⅲ）定量分离（其萃取率达９９．５％），共存的Ａｓ（Ｖ）等不干扰。同时证明，向萃Ａｓ（Ⅲ）后的液相中加过量的ＴｉＣｌ＿３溶液，可使５０ｍｇＡｓ（Ｖ）还原至Ａｓ（Ⅲ），继用苯萃取分离，经水反萃取之后，均以碘量法完成测定。方法简便、快速，干扰少，对Ａｓ（Ⅲ、Ｖ）的价态分析、具有广阔的应用前景。

A method of extraction-separation for high contents of As （ Ⅲ ） and As（V）has been investigated.It is shown50mg As（Ⅲ ） can be extracted quantitatively by benzene in HC1 medium(the extractable ratio is 99.5％)and coexistent As(V)does not interfere with the extraction-separation of As(Ⅲ)50mg AS(V)can also be extracted quantitatively after reduction toAs(Ⅲ) with TiCl_3 solution. As(Ⅲ) can be determined by iodimetry after re-extration with water. The method is simpleand rapid and many changeable valence metal ions do not interfere with the determination,so it will find promisingapplication is the valence state analysis of the high contents of As（ Ⅲ ）and As（V）.