Ten different methods for determining total available residual chlorine, all based on the iodine-iodide reaction, were tested without modification on four sample matrices. Their precision was determined by seven replicate determinations. Accuracy, as compared to the iodometric starch titration method, was determined in terms of percent yield. Observations regarding advantages, disadvantages, deviations from the expected and problems involved in the determination are recorded. The data are presented in tables arranged for instructive purposes and in a figure intended to present the data in reduced form for easier appraisal. The information obtained can be used by the analyst in determining which method is most suitable for a particular matrix. The data show the importance of the nature of the sample matrix. The necessity of comparing several methods in order to be certain of the accuracy is also obvious given the data. This report covers a period from March 1976 to November 1976 and was completed as of November 12, 1976.

Ten different methods for determining total available residual chlorine, all based on the iodine-iodide reaction, were tested without modification on four sample matrices. Their precision was determined by seven replicate determinations. Accuracy, as compared to the iodometric starch titration method, was determined in terms of percent yield. Observations regarding advantages, disadvantages, deviations from the expected and problems involved in the determination are recorded. The data are presented in tables arranged for instructive purposes and in a figure intended to present the data in reduced form for easier appraisal. The information obtained can be used by the analyst in determining which method is most suitable for a particular matrix. The data show the importance of the nature of the sample matrix. The necessity of comparing several methods in order to be certain of the accuracy is also obvious given the data. This report covers a period from March 1976 to November 1976 and was completed as of November 12, 1976.

"This third edition of 'Methods for Chemical Analysis of Water and Wastes' contains the chemical analytical procedures used in U.S. Environmental Protection (EPA) laboratories for the examination of ground and surface waters, domestic and industrial waste effluents, and treatment process samples. Except where noted under 'Scope and Application, ' the methods are applicable to both water and wastewaters, and both fresh and saline water samples. The manual provides test procedures for the measurement of physical, inorganic, and selected organic constituents and parameters"--Abstract.