Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10560074 | Talanta | 2005 | 5 Pages |
Abstract
Nitrate determination in waters is generally carried out with cadmium filings and carcinogenic reagents or by reaction with phenolic compounds in highly concentrated sulfuric acid medium. In this work, it was developed a green analytical procedure for nitrate determination in natural waters based on direct spectrophotometric measurements in ultraviolet, using a flow-injection system with an anion-exchange column for separation of nitrate from interfering species. The proposed method employs only one reagent (HClO4) in a minimum amount (equivalent to 18 μL concentrated acid per determination), and allowed nitrate determination within 0.50-25.0 mg Lâ1, without interference of up to 200.0 mg Lâ1 humic acid; 1.0 mg Lâ1 NO2â; 200.0 mg Lâ1 PO43â; 75.0 mg Lâ1 Clâ; 50.0 mg Lâ1 SO42â and 15.0 mg Lâ1 Fe3+. The detection limit (99.7% confidence level) and the coefficient of variation (n = 20) were estimated as 0.1 mg Lâ1 and 0.7%, respectively. The results obtained for natural water samples were in agreement with those achieved by the reference method based on nitrate reduction with copperized cadmium at the 95% confidence level.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Wanessa Roberto Melchert, Fábio R.P. Rocha,