Integrated flow analysis platform for the direct detection of nitrate in water using a simplified chromotropic acid method
Cogan, Deirdre, Cleary, JohnORCID: 0000-0001-7282-4998, Phelan, Thomas, McNamara, Eoghan, Bowkett, Mark and Diamond, DermotORCID: 0000-0003-2944-4839
(2013)
Integrated flow analysis platform for the direct detection of nitrate in water using a simplified chromotropic acid method.
RSC Analytical Methods, 2013
(5).
pp. 4798-4804.
ISSN 1759-9660
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 (430 nm).The modified method allows for nitrate determination over the linear range 0.9–80 mg/L nitrate with a limit of detection of 0.73 mg/L
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.
Metadata
Item Type:
Article (Published)
Refereed:
Yes
Uncontrolled Keywords:
chemical sensors; water monitoring; nitrate; chromotropic acid