Spectrochemical determination of iron and copper in commercial oils

Summary Application of the internal standard method to the spectrochemical analysis of oils in conjunction with the use of a modified ashing technique has been shown to permit quantitative determination of copper to 0.001 p.p.m. and of iron to 0.01 p.p.m. The procedure has been tested by the addition of known amounts of copper and iron to oils and recovery has been found satisfactory. Results on several commercial oils are given to illustrate the range over which the method is applicable.