燃焼イオンクロマトグラフィーによるプラスチック中の塩素及び臭素の定量

Abstract

Accurate and precise determinations of chlorine and bromine in plastic samples were examined using combustion ion chromatography (CIC). The concentration of H2O2 as an absorption solution as well as the analytical methods with and without an internal standard of phosphate ion was optimized by a recovery test using standard solutions and certified reference materials (BCR-681 and NMIJ CRM 8137-a). When concentrated of H2O2 such as 1000 mg kg−1, was applied to CIC analysis, quantitative recovery could be obtained. Since the internal standard of the phosphate ion was lost by gas bubbling during the combustion process, the analytical results revealed higher values beyond those expected. On the other hand, the analytical results involving the calibration method without any internal standard were in good agreement with the certified values. The developed method was applied to analyze for chlorine and bromine in certified reference materials made by ABS resin (NMIJ CRM 8155-a). The analytical results obtained by CIC were in good agreement with these by an instrumental neutron activation analysis (INAA) as a complimentary analytical method. The uncertainty for each of chlorine and bromine by CIC analysis of NMIJ CRM 8155-a was 1.6%, which was consistent with that obtained by INAA. The limits of quantification for CIC analysis with 30 mg of plastic sample were 1 mg kg−1 for chlorine and 5 mg kg−1 for bromine.