A method is described, employing as the sample bottom mud from Linsley Pond, North Branford, Connecticut, for the determination of all detectable exchangeable cations lying between lithium and uranium on the periodic table. Dried (48 h 110°C) and ground (200 mesh) lake mud samples are leached successively with IN, <i>p</i>H 6.9 ammonium acetate. Another set of similarly prepared samples are leached with doubly distilled deionized water. The leachate is made up to 100 ml. This volume is then added to a beaker containing two grams of terephthalic acid. The liquid is evaporated on to the water-insoluble terephthalic acid. The dried material is ground and pressed into a pellet. Another set of samples is treated in a similar fashion except that methyl cellulose is used as a substrate. The advantages and disadvantages of the two substrates are discussed. The pressed pellets containing the absorbed detectable exchangeable cations are examined with a G. E. x-ray emission spectroscope for those elements present between fluorine and uranium, and the lighter elements are examined by use of optical emission. The method in both cases is described.
Ursula M. Cowgill, "Method to Determine all Detectable Exchangeable Cations Using X-Ray Emission and Optical Emission Spectroscopy," Appl. Spectrosc. 22, 415-419 (1968)