Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10560481 | Talanta | 2011 | 7 Pages |
Abstract
This paper proposes a new automated spectrophotometric method for the simultaneous determination of phosphate and arsenate without pre-treatment, which is faster, simpler, less expensive and hazardous than other well-known methods used with water samples. Such method is based on the different kinetic characteristics of complex formation of phosphate and arsenate with ammonium molybdate. A flow system was used in order to achieve good mixing and to provide precise time control. All the measurements were performed at the isosbestic point wavelength (885 nm). Chemical variables were optimized by factorial design (ammonium molybdate 0.015 mol Lâ1, potassium antimony tartrate 1 Ã 10â4 mol Lâ1, and sulphuric acid 0.7 mol Lâ1). An appropriate linear range for both analytes (0.50-8.00 μmol Lâ1), good inter-day reproducibility (4.9% [P] and 3.3% [P + As]) and a sample throughput of 6 hâ1 were obtained. The detection limits are 0.4 μmol Lâ1 P and 0.19 μmol Lâ1 [P + As] (3.3 Sy/x). The method was validated.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Laura Borgnino, Valeria Pfaffen, Pedro J. Depetris, Miriam Palomeque,