Proton induced γ-ray analysis of atmospheric aerosols for carbon, nitrogen, and sulfur composition

A technique for the simultaneous quantitative determination of carbon, nitrogen, and sulfur using in-beam γ-ray spectrometry has been developed for use with atmospheric aerosol samples. Samples are collected on quartz filters, and the aerosol composition is determined by analyzing the γ rays emitted following the inelastic scattering of 7.0-MeV protons. Samples are nondestructively irradiated for 1000 s in a helium atmosphere, are not subjected to reduced pressures, and can be used for subsequent analysis. Detection limits for atmospheric samples are in the μg/cm2 range with a precision of 5%. The technique is compared with several more conventional methods of analysis. 5 figures