激光荧光法测定八氧化三铀中的痕量钐、铕、铽和镝

DETERMINATION OF ULTRATRACE AMOUNT OF SAMARIUM, EUROPIUM, TERBIUM AND DYSPROSIUM IN URANIUM OXIDE BY LASER-INDUCED FLUORESCENCE SPECTROMETRY

本文确定了钐、铕在噻吩甲酰三氟丙酮(TTA)和三辛基氧膦(TOPO)体系及铽、镝在钛铁试剂(Tiron)体系的最佳测定条件。对钐、铕、铽、镝的测定下限分别为20ppt、5ppt、5ppt及40ppt。同时采用P507萃淋树脂在4mol/L酸介质中达到大量铀与痕量稀土的定量分离,再利用不同酸度的盐酸-氯化钠混合溶液分别淋洗钐、铕、铽、镝、达到分离的目的。用该法进行了光谱纯八氧化三铀样品分析及加入回收,方法精密度为±10％,加入回收为95—105％

The determination of ultratrace amount of Sm, Eu, Tb and Dy by laserinduced fluorescence spectrometry is investigated. The fluorescence of Sm and Eu is determined in pH range of 4.0-7.0. The concentrations of 2-thenoyl-trifluoroacetone, trioctylphosphine oxide and Triton-X-100 are 1.5×10-4M, 3.0×10-5M and 1.5×10-4-2.0×10-2M, respectively. The determination limits of Sm and Eu are 20PPt and 5 ppt respectively. The fluorescence determination of Tb and Dy is carried out in basic solution of Tiron. The determination limits of Tb and Dy are 5PPt and 40PPt respectively. P507 levextrel resion is used as the stationary phase for chromatographic separation. On 4N hydrochloric acid, the seperation of ultratrace rare earths from large amount of uranium is developed. When hydrochloric acid of different acidity is used as eluant, the four rare earth elements can be seperated from each other quantitatively. Finally, Sm, Eu, Tb, Dy in the uranium oxide sample have been analysed. The precision is better than +10%.