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A technique for the simultaneous quantitative determination of carbon, nitrogen, and sulfur using in-beam y-ray spectrometry has been developed for use with atmospheric aerosol samples. Samples are collected on quartz filters, and the aerosol composltlon is determined by analyzing the y 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 pg/cm* range with a precision of 5 % . The technique is compared with several more conventional methods of analysis.

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This paper describes experiments and results that have been ob tained from a pyrolysis/gas chromatography/mass spectroscopy study on chlori nated polyvinyl chloride (CPVC-65% Cl) containing two commercially available plasticisers, namely, DOP and Santicizer 2148 with and without modest amounts of an iron (III) smoke suppressing compound. Careful analysis of the mass spectra obtained from the pyrolysis products has shown that the smoke suppressing effect of basic iron (III) oxide (FeOOH) is essentially the result of two sets of chemical reactions. This iron compound reacts with the CPVC poly mer and the plasticisers present. Increased amounts of char formed from the CPVC combined with changes in the path of decomposition during pyrolysis of both plasticisers to give fewer smoke precursor molecules resulted in a signifi cant reduction in smoke formation.

Aus dem Tetrachlor‐cyclopentadienonketal (I) entsteht mit dem Vinylacetat (II) ein Gemisch der beiden Addukte (III).