Colorimetric Determination of Nitrate Plus Nitrite in Water by Enzymatic Reduction, Automated Discrete Analyzer Methods - Couverture souple

Patton, Charles J; Kryskalla, Jennifer R

Couverture souple

ISBN 10 : 150022331X ISBN 13 : 9781500223311

Editeur : CreateSpace Independent Publishing Platform, 2014

Synopsis

This report documents work at the U.S. Geological Sur- vey (USGS) National Water Quality Laboratory (NWQL) to validate enzymatic reduction, colorimetric determinative meth- ods for nitrate + nitrite in filtered water by automated discrete analysis. In these standard- and low-level methods (USGS I-2547-11 and I-2548-11), nitrate is reduced to nitrite with nontoxic, soluble nitrate reductase rather than toxic, granular, copperized cadmium used in the longstanding USGS auto- mated continuous-flow analyzer methods I-2545-90 (NWQL laboratory code 1975) and I-2546-91 (NWQL laboratory code 1979). Colorimetric reagents used to determine resulting nitrite in aforementioned enzymatic- and cadmium-reduction meth- ods are identical. The enzyme used in these discrete analyzer methods, designated AtNaR2 by its manufacturer, is produced by recombinant expression of the nitrate reductase gene from wall cress (Arabidopsis thaliana) in the yeast Pichia pastoris. Unlike other commercially available nitrate reductases we evaluated, AtNaR2 maintains high activity at 37°C and is not inhibited by high-phenolic-content humic acids at reaction temperatures in the range of 20°C to 37°C. These previously unrecognized AtNaR2 characteristics are essential for success- ful performance of discrete analyzer nitrate + nitrite assays (henceforth, DA-AtNaR2) described here.

Détails de l'édition

• Éditeur: CreateSpace Independent Publishing Platform
• Date d'édition: 2014
• Langue: anglais
• ISBN 10: 150022331X
• ISBN 13: 9781500223311
• Reliure: Paperback
• Nombre de pages: 44
• Coordonnées du fabricant: non disponible
• Personne responsable: non disponible