Journal of the Brazilian Chemical Society (Jan 1999)

Spectrophotometric determination of uranium using 2-(2- Thiazolylazo)-p-Cresol (TAC) in the presence of surfactants

  • Teixeira Leonardo Sena Gomes,
  • Costa Antonio Celso Spínola,
  • Ferreira Sérgio Luís Costa,
  • Freitas Maria de Lourdes,
  • Carvalho Marcelo Souza de

Journal volume & issue
Vol. 10, no. 6
pp. 519 – 522

Abstract

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A sensitive and selective spectrophotometric method is proposed for the rapid determination of uranium using 2-(2- Thiazolylazo)-p-Cresol (TAC). The reaction between TAC and uranium (VI) is instantaneous at pH 6.5 and the absorbance remains stable for over 3 h. N-cetyl-N,N,N-trimethylamonium bromide (CTAB) and triton X-100 are used for increasing the sensitivity and solubility of the system respectively. The method allows the determination of uranium in the range from 0.30 to 12.0 mug mL-1 with a molar absorptivity of 1.31 x 10(4) L mol-1 cm-1 and features a detection limit of 26 ng mL-1 at 588 nm. The selectivity of the reagent was improved by the use of (1,2-cyclohexylenedinitrilo) tetraacetic acid (CyDTA) as masking agent. The proposed method has been successfully applied to the determination of uranium in mine drainage waters. The precision (R.S.D. < 2%) and the accuracy obtained were satisfactory.

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