Quantitative surface analysis of nbs standard materials and mt. st. helens ash by electron spectroscopy for chemical analysist

Results are presented which develop a quantitative method of surface analysis by ESCA for complex heterogeneous systems. Calibration and application of the method to determination of surface weight percentages are discussed. Mt. St. Helens Ash is used to authenticate the method; results agree with bulk analysis to ±20%. Results from NBS standard materials are used to establish detection limits of 0.1% by weight for most materials. The minimum detectable concentration of surface segregated species can be as low as 200–300 ppm. Results from the NBS standards establish a surface composition for these species, and allow deduction about particle morphology; organics and volatile metals are likely to be surface segregated and mineral species are segregated to the particle core.