Published November 1985 | Version v1
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Ion exchange separation of nitrate from uranium compounds and its determination by spectrophotometry and ion chromatography

Description

A procedure for the separation of nitrate from uranium compounds by retaintion of uranyl ion on a cationic ion exchanger and its determination in the effluent is described. Nitrate is analysed by the spectrometric method with 1-phenol-2,4-dissulphonic acid. This determination covers the 1 to 10 μg NO-3/mL range and requires an amount of 10 to 100 μg NO-3. The main interference is uranium (VI) due its own intense yellow color. This difficulty is overcome by the complete separation of UO2++ with the cationic resin. Alternatively, the ion chromatography technique is used for the determination of nitrate in the effluent of the cationic resin. The determination was easily made by the comparison of the nitrate peak hights of the analyte and the standard solutions. The ion chromatography method is very sensitive (0,3 μg NO-3/mL), reproducible and suitable for routine analysis and permits the determination of fraction of part per million of nitrate in uranium. The results of nitrate determination using both spectrophotometric and ion chromatography techniques are compared. The method is being routinely applied for the quality control of uranium compounds in the fuel cycle, specially uranium oxide, ammonium diuranate, uranium peroxide and ammonium uranyl tricarbonate. (Author)

Availability note (English)

MF available from INIS under the Report Number.

Abstract (Portuguese)

Descreve-se um procedimento simples e seguro para a separacao de nitrato em compostos de uranio por fixacao de ion UO2++ em resina cationica forte e determinacao do ion nitrato no efluente. Determina-se o nitrato por metodo espectrofotometrico usando-se o acido 1-fenol-2,4-dissulfonico, formando-se pela reacao de ambos um complexo de coloracao amarela, cuja intensidade e maior em meio alcalino. O intervalo de determinacao de nitrato por este metodo e de 1 a 10 μg NO-3/mL, requerendo μa massa de 10 a 100 microgramos de nitrato, facilmente atingivel pela concentacao via resina cationica. Embora sensivel, este metodo apresenta varios interferentes, entre eles o uranio-VI, por ser amarelo. Esta dificuldade e contornada pela separacao em resina. Como alternativa usa-se o metodo da cromatografia de ions, injetando-se no aparelho o efluente da coluna de resina cationica contendo ion nitrato. Faz-se a determinacao por comparacao das alturas dos picos nos cromatogramas obtidos com a solucao analise e com solucoes padroes. O metodos e muito sensivel, reprodutivel e conveniente para analises de rotina, permitindo a determinacao de fracoes de partes por milhao de NO-3/U. O trabalho compara o metodo colorimetrico com a determinacao por cromatografia de ions. A tecnica se aplica para as solucoes de uranio e compostos de interesse no ciclo do combustivel nuclear, especialmente oxidos, diuranatos, peroxidos e tricarbonato de uranilo e amonio. (Autor)

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Additional details

Additional titles

Original title (Portuguese)
Separacao de nitrato em compostos de uranio por troca ionica, sua determinacao espectrofotometrica e por cromatografia de ions

Publishing Information

Imprint Pagination
15 p.
Report number
IPEN-PUB--90