The Controlled Atmosphere Direct Current Arc for the Quantitative Determination of Trace Metals in Organics

Abstract

A method has been developed to permit the quantitative determination of trace metals in polypropylene and other organic materials in which the total ash content ranges from 0.10 per cent to less than 0.001 per cent by weight. A small sample of the material is ashed directly in the electrode. A fixed amount of germanium internal standard solution is added to the electrode and dried Standards are prepared by adding weighed amounts of a plastic dispersion containing known amounts of the elements to be determined to specially prepared electrodes. Using a controlled atmosphere chamber the prepared electrodes are excited with a dc arc in an atmosphere of argon and oxygen and the spectra recorded photographically.