INFLUENCE OF OXYGEN CONCENTRATION DURING SEMI- AND LOW-VOLATILE ORGANIC HALOGEN COMPOUNDS DECOMPOSITION PROCESS BY BARRIER DISCHARGE ATOMIC EMISSION SPECTROMETRY

摘要

A group parameter approach using 'total organic halogen' is effective for monitor gaseous organic halogen compounds including bromine, chlorine and fluorine from combustion. We developed barrier discharge radiofrequency helium plasma - atomic emission spectrometry (AES) for detecting semi- and low-volatile organic halogens (SLVOXs), which are amenable to collection by Carbotrap TM or Carboxen TM and analysis using thermal desorption. The optimal carrier gas flow rates at the injection and desorption lines were established at 100 mL min-1. The detection range for these SLVOX compounds in the gaseous samples was from 10 ng to tens of micrograms. Compared to Cl or Br, measuring F was difficult because its wavelength is near that of air. The barrier discharge radiofrequency helium plasma AES measured from 85 to 103% of the SLVOX in the sampling gas. Carbotrap B was appropriate for high boiling point compounds, while Carbotrap C was suitable for the determination of organic halogens with middle boiling points ranging from 200 to 230 ℃. Carboxen 1000 was suitable for the determination of organic halogens with boiling points below 100 ℃. Base on the optimal analysis condition, plastic which containing chlorine was destructed under different oxygen concentration. The lower oxygen concentration showed the lower organic halogen production.