1. For an extensive review of these procedures see Anal. Chem., Annual (Analyt.) Reviews, sections Ion-Exchange, Nucleonics 30, No. 4, Part II (1958); 32, No.5 (1960); 34, No. 5 (1962); 36, No. 5 (1964); 38, No. 5 (1966), and section Water 31, No. 4, Part II (1959); 33, No. 5 (1961); 35, No. 5 (1963); 37, No. 5 (1965).
2. Dowex-ion exchange. Midland, Michigan: The Dow Chemical Company 1964.
3. Dyrssen, D.: Acta Chem. Scand. 11, 1277 (1957); cf. Z. Anal. Chem. 163, 136 (1958).
4. —, and D. H. Liem: Acta Chem. Scand. 14, 1091 (1960).
5. Evans, E. A., and J. L. Huston: Anal. Chem. 24, 1482 (1952).