空気燃焼-イオンクロマトグラフィーによるRoHS指令に対応した有機材料中のハロゲンの定量

摘要

2006年，欧州連合（EU）においてRoHS指令(Restriction of the use of certain hazardous substances in electric and electrical equipment)が施行されて以降，製品中のRoHS対象物質の濃度管理が不可欠となっている．RoHS指令の対象項目の試験方法は，IEC（国際電気標準会議）の国際規格で示されているものの，臭素系難燃剤であるPBBs (polybrominated biphenyls)やPBDEs (polybrominated diphenyl ethers)については，ソックスレ一法での抽出後ガスクロマトグラフ質量分析法で定量するという煩雑かつ測定に時間を要する方法となっている．%An analysis method for halogens in organic materials was examined by air combustion coupled with ion chromatography. In this system, a sample of 0.1-0.5 g was weighted and ignited slowly in a quartz combustion tube at 1000℃ with air gas at a flow rate of 2.5 L min~(-1) The combustion products were collected into 20 mL of a 40 mM potassium hydroxide solution in which 20 μL of 3 % hydrogen peroxide was added for reducing. Halogens (F, Cl, Br) were determined by ion chromatography. Recoveries for the halogens tested were almost 100 ± 10 %. The accuracy of the proposed method was evaluated by analyzing a standard reference material of polyethylene (NMIJ CRM8108-a, AIST Japan and ERM-EC680K, IRMM Belgium). The values of Br and Cl obtained with the present method showed good agreement with the certified values, as judged from standard deviation. The present method was also applied to proficiency testing for the determination of bromine in a plastic material. The analytical results for the z score were 0.199 (low con.) and-0.597 (high con.).