Derived naturally or as the result of human intervention, nitrate is ubiquitous in our environment. It is essential for plant and animal growth, but in excess amounts becomes a toxin and can even act as indicator analyte alerting scientists to other contaminants in the environment. (1) As we learn more about nitrogen’s role in our natural surroundings and our own bodies, the need to monitor this chemical species is increasing and finding a reliable, inexpensive method to accomplish this task is vital.
Nitrate occurs in all types of sample matrixes such as drinking water, saltwater, blood serum, urine and soil and plant extracts and is analyzed in just about as many industries including agricultural, water resource management, food, environmental sciences and biomedical research. In the past, techniques used to measure nitrate directly as NO3 were unreliable, costly and affected by interferences from components in the sample matrixes themselves. Today, nitrate is most often measured indirectly by reducing NO3 to NO2 using a cadmium coil and analyzed colorimetrically in a flow injection analysis system. Recently however, a new and exciting method has been developed.
With the discovery of the physiological effects of nitric oxide in the human body, nitrate analysis is becoming a focus outside of just agricultural and environmental industries, making it imperative to develop a technique where total accuracy in determining nitrate concentrations is necessary. In response to this need, James Crutchfield and John Grove have introduced a simple, more efficient way to reduce NO3 to NO2 and have developed a new way of using the alternative 96-well microplate to analyze nitrate in a variety of matrixes — the new cadmium reduction device.
The new cadmium reduction device for microplates is not only accurate and less expensive to run, but doesn’t require an assay kit, eliminates interferences in the reduction process, eliminates the need for ultrafiltration or coprecipitation, is compatible with a microplate reader analytical system, requires no special expertise, no dedicated instrumentation, the reductor itself will last through the analysis of thousands of samples and reduction time can be extended for near complete conversion of NO3 to NO2.
For more information read “A New Cadmium Reduction Device for the Microplate Determination of Nitrate in Water, Soil, Plant Tissue and Physiological Fluids” by James D. Crutchfield and John H. Grove and get the details on analysis of water samples or KCL extracts of soil, analysis of plant tissue extracts, analysis of physiological fluids using cluster tubes, determination of NO3 in pure solutions, determination of NO3 in natural water, determination of NO3 in soil extracts, determination of NO3 in plant tissue extracts and determination of NO3 in physiological fluids.
(1) Jim Lundy. “Nitrate-Nitrogen (Nitrate) Source Water Protection.” Minnesota Department of Health.17 April 2014. Web. 24 July 2014.