Integrated flow analysis platform for the direct detection of nitrate in water using a simplified chromotropic acid method
| Autor: | Eoghan McNamara, Thomas Phelan, John Cleary, Deirdre Cogan, Dermot Diamond, Mark Bowkett |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Analytical Methods. 5:4798 |
| ISSN: | 1759-9679 1759-9660 |
| Popis: | This work describes the first use of a direct nitrate analyser using chromotropic acid. A simplified chromotropic acid method eliminating several steps previously associated with this method is employed in the platform. In a sulphuric acid medium, chromotropic acid reacts with nitrate ions and produces a characteristic yellow colour associated with an absorbance band in the visible region (λmax = 430 nm). The modified method allows for nitrate determination over the linear range 0.9–80 mg L−1 nitrate with a limit of detection of 0.73 μg L−1 nitrate. Validation was achieved by analysing water samples from various sources including groundwater, trade effluent and drinking water by the modified method and by ion chromatography. The method was implemented on a flow analysis platform incorporating a paired emitter–detector diode (PEDD) as the optical detector. An excellent correlation coefficient of 0.993 was obtained between the modified method and ion chromatography. The modified chromotropic acid method represents a rapid, simple, low cost technique for the direct determination of nitrate in water. |
| Databáze: | OpenAIRE |
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