Selective micelle mediated extraction of thorium from uranium and some lanthanides and its determination by inductively coupled plasma-optical emission spectrometry

An eco-friendly, selective, accurate and rapid procedure was developed for determination of Th4+ in the presence of H6+, Sm3+, La3+, Ce4+, Ho3+ and Er3+. Morin selectively forms a complex with Th4+ at pH range 2.0-4.0 that quantitatively extracted into the surfactant-rich phase in the presence of 0.1% (v/v) Triton X-114 and 0.1% (w/v) KI at room temperature. The developed procedure was optimized and used for determination of Th4+ in complex specimens (waste water and phosphate rocks) by inductively coupled plasma - optical emission spectrometry. The procedure possesses wider analytical range (0.3-500.0 mu g L-1) and lower detection limit (0.11 mu g L-1) compared to other published CPE procedures for Th4+. For a 50.0 mL sample, the enrichment factor was 49.5. The interference effect of most concomitant ions was negligible. The accuracy of the method was estimated by good recoveries (95.0-100.0%) of Th4+ from spiked samples.

Automated summary

An eco-friendly and selective method was developed for the determination of Th4+ in the presence of various ions. The method showed high accuracy and efficiency, with a wider analytical range and lower detection limit compared to other published procedures.