Document Type


Publication Date

January 1978


Introduction: The 1976 edition of "Methods of Chemical Analysis of Water and Wastes" describes chemical analytical procedures to be sued in Water Quality Office (WQO) laboratoires. The methods were chose through the combined efforts of the Regional Analytical Quality Control (AQC) Coordinators, Laboratory Quality Control Officers, and other senior chemicsts in both federal and state laboratories. Method selection was based on the following criteria: 1. The method should measure the desired constitutent with precision and accuracy suffiecient to meet the data needs of WQO in the presence of the interferences normally encountered in polluted waters. 2. The procedures should utilize the equipment and skillso normally available in the typical water pollution control laboratory. 3. The selected methods are in use in many laboraties or have been sufficiently tested to establish their validity. 4. The mthods should be sufficiently rapid to permit routine use for the examination of a large number of samples. Except where noted under "scope and Application" for each constituent, the methods can be used for the measurement of the indicated constituent in both water and wastewaters and in oboth saline and fresh water samples. Instrumental methods have been selected in preference to manual procedures because of the improved speed, precision, and accuracy. Procedures for the Technicon AutoAnalyzer have been included for laboratories having this equipment available. Precision and accuracy statements have been derived from interlaboratory studies conducted by the Methods and Performance Activity, Analytical Quality Control Laboratory, WQO; the American Society for Testing Materials; or the Analytical Reference Service of the Public Health Service, DHEW. Specific instructions for the handling and preservation of samples cannot be given because of the wide variability in types of samples and local sampling situations. However, certain general principles should be followed. Wherever possible, the sampling program should be designed to provide for the shortest possible interval between sample collection and analysis. Positive steps should be taken to maintain both the concentration and the physical state of the constituents to be measureed.