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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Determination of chromium (VI) by flame atomic absorption spectrometry after cloud point extraction and preconcentration

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Author(s):
A. Sussulini [1] ; M. A. Z. Arruda [2]
Total Authors: 2
Affiliation:
[1] Universidade Estadual de Campinas. Instituto de Química. Departamento de Química Analítica - Brasil
[2] Universidade Estadual de Campinas. Instituto de Química. Departamento de Química Analítica - Brasil
Total Affiliations: 2
Document type: Journal article
Source: Eclética Química; v. 31, n. 1, p. 73-80, 2006-00-00.
Field of knowledge: Physical Sciences and Mathematics - Chemistry
Abstract

The present work reports a method for chromium (VI) determination by flame atomic absorption spectrometry (FAAS) after cloud point extraction and preconcentration. Chromium (VI) is complexed with 1,5-diphenylcarbazide (DFC) in acidic medium (pH 2.0) and it is extracted into 25 µL of surfactant-rich phase containing Triton X-114. The variables that affect the cloud point formation, such as the surfactant (0.1-1.0% m/v) and complexant (0.01-0.80% m/v) concentrations, time of complexation (0-60 min), and effect of electrolyte NaCl (0-20% m/v) addition are evaluated. Under optimized conditions, 0.3% m/v Triton X-114, 0.05% m/v DFC and 10% m/v NaCl are used for chromium (VI) extraction. This method allows detection and quantification limits of 0.4 µg L-1 and 1.5 µg L-1, respectively, and a linear calibration range from 5 to 500 µg L-1. The preconcentration factor obtained is 27 and the extraction efficiency achieved varies from 87 to 99.3%. (AU)