Author: Charles J Patton
Publisher: CreateSpace
ISBN: 9781500223311
Category : Technology & Engineering
Languages : en
Pages : 44
Book Description
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.
Colorimetric Determination of Nitrate Plus Nitrite in Water by Enzymatic Reduction, Automated Discrete Analyzer Methods
Author: Charles J Patton
Publisher: CreateSpace
ISBN: 9781500223311
Category : Technology & Engineering
Languages : en
Pages : 44
Book Description
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.
Publisher: CreateSpace
ISBN: 9781500223311
Category : Technology & Engineering
Languages : en
Pages : 44
Book Description
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.
Statistical Methods in Water Resources
Author: D.R. Helsel
Publisher: Elsevier
ISBN: 0080875084
Category : Science
Languages : en
Pages : 539
Book Description
Data on water quality and other environmental issues are being collected at an ever-increasing rate. In the past, however, the techniques used by scientists to interpret this data have not progressed as quickly. This is a book of modern statistical methods for analysis of practical problems in water quality and water resources.The last fifteen years have seen major advances in the fields of exploratory data analysis (EDA) and robust statistical methods. The 'real-life' characteristics of environmental data tend to drive analysis towards the use of these methods. These advances are presented in a practical and relevant format. Alternate methods are compared, highlighting the strengths and weaknesses of each as applied to environmental data. Techniques for trend analysis and dealing with water below the detection limit are topics covered, which are of great interest to consultants in water-quality and hydrology, scientists in state, provincial and federal water resources, and geological survey agencies.The practising water resources scientist will find the worked examples using actual field data from case studies of environmental problems, of real value. Exercises at the end of each chapter enable the mechanics of the methodological process to be fully understood, with data sets included on diskette for easy use. The result is a book that is both up-to-date and immediately relevant to ongoing work in the environmental and water sciences.
Publisher: Elsevier
ISBN: 0080875084
Category : Science
Languages : en
Pages : 539
Book Description
Data on water quality and other environmental issues are being collected at an ever-increasing rate. In the past, however, the techniques used by scientists to interpret this data have not progressed as quickly. This is a book of modern statistical methods for analysis of practical problems in water quality and water resources.The last fifteen years have seen major advances in the fields of exploratory data analysis (EDA) and robust statistical methods. The 'real-life' characteristics of environmental data tend to drive analysis towards the use of these methods. These advances are presented in a practical and relevant format. Alternate methods are compared, highlighting the strengths and weaknesses of each as applied to environmental data. Techniques for trend analysis and dealing with water below the detection limit are topics covered, which are of great interest to consultants in water-quality and hydrology, scientists in state, provincial and federal water resources, and geological survey agencies.The practising water resources scientist will find the worked examples using actual field data from case studies of environmental problems, of real value. Exercises at the end of each chapter enable the mechanics of the methodological process to be fully understood, with data sets included on diskette for easy use. The result is a book that is both up-to-date and immediately relevant to ongoing work in the environmental and water sciences.
Field Guide for Collecting Samples for Analysis of Volatile Organic Compounds in Stream Water for the National Water-Quality Assessment Program
Author: L. R. Shelton
Publisher:
ISBN:
Category : Volatile organic compounds
Languages : en
Pages : 28
Book Description
Publisher:
ISBN:
Category : Volatile organic compounds
Languages : en
Pages : 28
Book Description
Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory
Author: Donna L. Rose
Publisher:
ISBN:
Category : Gas chromatography
Languages : en
Pages : 44
Book Description
Publisher:
ISBN:
Category : Gas chromatography
Languages : en
Pages : 44
Book Description
Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory
Author:
Publisher:
ISBN:
Category : Gas chromatography
Languages : en
Pages : 86
Book Description
Publisher:
ISBN:
Category : Gas chromatography
Languages : en
Pages : 86
Book Description
Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory
Author: Charles J. Patton
Publisher:
ISBN:
Category : Water
Languages : en
Pages : 44
Book Description
Publisher:
ISBN:
Category : Water
Languages : en
Pages : 44
Book Description
Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory
Author: Virendra Kumar Jha
Publisher:
ISBN:
Category : Flame photometry
Languages : en
Pages : 40
Book Description
Publisher:
ISBN:
Category : Flame photometry
Languages : en
Pages : 40
Book Description
Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory
Author: John R. Garbarino
Publisher:
ISBN:
Category : Fluorescence spectroscopy
Languages : en
Pages : 30
Book Description
Publisher:
ISBN:
Category : Fluorescence spectroscopy
Languages : en
Pages : 30
Book Description
Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory
Author:
Publisher:
ISBN:
Category : Electronic government information
Languages : en
Pages : 52
Book Description
Publisher:
ISBN:
Category : Electronic government information
Languages : en
Pages : 52
Book Description
Interpreting and Reporting Radiological Water-quality Data
Author: David E. McCurdy
Publisher:
ISBN:
Category : Environmental sampling
Languages : en
Pages : 33
Book Description
Publisher:
ISBN:
Category : Environmental sampling
Languages : en
Pages : 33
Book Description