A method employing a direct reading spectrochemical procedure for the quantitative determination of 19 minor elements in water is presented. Ag, Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Mo, Mn, Ni, P, Pb, Sr, V, and Zn are determined in concentrated water samples by the rotating disc-high-voltage spark technique. Using background as the internal standard, concentrations in the order of 0 01 to 100 mg/1 in the processed sample are determined in a matter of minutes by converting the "counts" from a sequential read-out system on a drum calculator. Recoveries of the elements from known solutions varied from 80 to 113 percent at the 90 percent confidence level.
John F. Kopp and Robert C. Kroner, "A Direct-Reading Spectrochemical Procedure for the Measurement of Nineteen Minor Elements in Natural Water," Appl. Spectrosc. 19, 155-159 (1965)