Selective extraction and separation of thorium from monazite using N-phenylbenzo-18-crown-6-hydroxamic acid

被引：16

作者：

Agrawal, YK ^{[1
]}

Vora, SB

机构：

[1] Gujarat Univ, Sch Sci, Dept Chem, Ahmedabad 380009, Gujarat, India

[2] GMDC Sci & Res Ctr, Ahmedabad 380052, Gujarat, India

来源：

MICROCHIMICA ACTA | 2003年 / 142卷 / 04期

关键词：

thorium; crown hydroxamic acid; monazite sand;

D O I：

10.1007/s00604-003-0025-1

中图分类号：

O65 [分析化学];

学科分类号：

070302 ; 081704 ;

摘要：

A method for the liquid-liquid extraction, separation, preconcentration and trace determination of thorium with N-phenylbenzo-18-crown-6-hydroxamic acid (PBCHA) is described. Thorium is extracted from the dichloromethane solution of PBCHA at pH 4.5 which gives a colourless extract (lambda(max) 375 nm, epsilon = 1.5 x 10(4) L mol(-1) cm(-1). linear range following Beer's law 0.77-18.48 mug mL(-1)). The extract is directly inserted into the plasma for ICP-AES measurements of thorium. A linear calibration graph was obtained between 10 and 130 ng mL(-1) of thorium. The proposed method has been applied for the separation and determination of thorium in the presence of several ions in monazite sand, rare earths, sand and sea water samples. The thorium-PBCHA complexes are very stable, having the formation constant (log beta(2)) 13.45 compared to lanthanum (log beta(2)) 2.95. cerium (log beta(2)) 2.95 and uranium (log beta(2)) 3.80. Hence, thorium can easily be separated and determined in monazite sand.

引用

页码：255 / 261

页数：7