On-line lab-in-syringe cloud point extraction for the spectrophotometric determination of antimony

Author(s)

Frizzarin, Rejane M. ^[1] ; Portugal, Lindomar A. ^[2] ; Estela, Jose M. ^[2] ; Rocha, Fabio R. P. ^[1] ; Cerda, Victor ^[2]

Affiliation

^[1] Univ Sao Paulo, Ctr Energia Nucl Agr, BR-13400970 Piracicaba, SP - Brazil

^[2] Univ Balearic Isl, Analyt Environm Chem Lab, Palma De Mallorca 07122 - Spain

• Document type: Journal article
• Source: Talanta; v. 148, p. 694-699, FEB 1 2016.
• Web of Science Citations: 19

Abstract

Most of the procedures for antimony determination require time-consuming sample preparation (e.g. liquid-liquid extraction with organic solvents), which are harmful to the environment. Because of the high antimony toxicity, a rapid, sensitive and greener procedure for its determination becomes necessary. The goal of this work was to develop an analytical procedure exploiting for the first time the cloud point extraction on a lab-in-syringe flow system aiming at the spectrophotometric determination of antimony. The procedure was based on formation of an ion-pair between the antimony-iodide complex and H+ followed by extraction with Triton X-114. The factorial design showed that the concentrations of ascorbic acid, H2SO4 and Triton X-114, as well as second and third order interactions were significant at the 95% confidence level. A Box-Behnken design was applied to obtain the response surfaces and to identify the critical values. System is robust at the 95% confidence level. A linear response was observed from 5 to 50 mu g L-1, described by the equation A=0.137 + 0.050C(Sb) (r=0.998). The detection limit (99.7% confidence level), the coefficient of variation (n=5; 15 mu g L-1) and the sampling rate was estimated at 1.8 mu g L-1, 1.6% and 16 h(-1), respectively. The procedure allows quantification of antimony in the concentrations established by environmental legislation (6 mu g L-1) and it was successfully applied to the determination of antimony in freshwater samples and antileishmanial drugs, yielding results in agreement with those obtained by HGFAAS at the 95% confidence level. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 11/23498-9 - Advanced flow systems for technological, agronomical and environmental analysis
• Grantee: Elias Ayres Guidetti Zagatto
• Support Opportunities: Research Projects - Thematic Grants