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

Development of a spectrophotometric Sequential Injection Analysis (SIA) procedure for determination of ammonium: A Response Surface Methodology (RSM) approach

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Author(s):
Infante, Carlos M. C. [1] ; Masini, Jorge C. [1] ; dos Santos, Allan C. V. [1]
Total Authors: 3
Affiliation:
[1] Univ Sao Paulo, Inst Quim, BR-05513970 Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Microchemical Journal; v. 98, n. 1, p. 97-102, MAY 2011.
Web of Science Citations: 5
Abstract

This paper describes the optimization and use of a Sequential Injection Analysis (SIA) procedure for ammonium determination in waters. Response Surface Methodology (RSM) was used as a tool for optimization of a procedure based on the modified Berthelot reaction. The SIA system was designed to (i) prepare the reaction media by injecting an air-segmented zone containing the reagents in a mixing chamber, (ii) to aspirate the mixture back to the holding coil after homogenization, (iii) drive it to a thermostated reaction coil, where the flow is stopped for a previously established time, and (iv) to pump the mixture toward the detector flow cell for the spectrophotometric measurements. Using a 100 mu mol L(-1) ammonium solution, the following factors were considered for optimization: reaction temperature (25 - 45 degrees C), reaction time (30 - 90 s), hypochlorite concentration (20 - 40 mmol L(-1)) nitroprusside concentration (10 - 40 mmol L(-1)) and salicylate concentration (0.1 - 0.3 mol L(-1)). The proposed system fed the statistical program with absorbance data for fast construction of response surface plots. After optimization of the method, figures of merit were evaluated, as well as the ammonium concentration in some water samples. No evidence of statistical difference was observed in the results obtained by the proposed method in comparison to those obtained by a reference method based on the phenol reaction. (C) 2010 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 08/09284-3 - Development of methodologies for determination of organic substances using Sequential Injection Analysis (SIA) and high performance liquid chromatography in monolithic columns
Grantee:Carlos Martín Infante Córdova
Support Opportunities: Scholarships in Brazil - Post-Doctoral