Alizarin-s, a reagent for thorium. a gravimetric, colorimetric, and spectrophotometric study

✍ Scribed by D.V.N. Sarma; Bh.S.V. Raghava Rao

• Publisher: Elsevier Science
• Year: 1955
• Tongue: English
• Weight: 638 KB
• Volume: 13
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/s0003-2670(00)87915-5

✦ Synopsis

ALTZARIN-S,

A REAGENT FOR THORIUM.

A GRAVIMETRIC, COLORIMETRIC, AND SPECTROPHOTOMETRIC STUD-13~cr~r suggested the separation of scandium and thorium from rare earths by prccipitation with 2.5 o/o alizarin-S solution and subsequent treatment with 30 o/O acetic acid. The experimental details arc not available and preliminary experiments indicated that the thorium alizarin-S complex dissolves appreciably even in very dilute acetic acid. A further investigation was undertaken adopting the following procedure. Pvccipitnlio9r of fhoriirnr wilh aliznfin-S IO ml of pure thorium nitrate containing o.oG87 g of ThO, wcrc pipcttcd into a 400 ml bcakcr to which wcrc added IO ml of 50% ammonium nitrate and the desired quantity of 2N acetic acid. The mixture was diluted to about 100 ml and hcatcd to b3iling. IO ml of 2.5 o/o alizarin-S were added in a thin stream with continuous stirring. The slimy prccipitatc was allowed to scttlc, filtered through Whatman No. 42 and wauhcd with 5 O/-ammonium nitrate aciclificcl with a few drops of 2N acetic xicl. The prccipitatc was ignited at 300 to x000 o C and weighed as 'IhO,.