Application of secondary ion mass spectrometry to the measurement of lead isotope ratio in individual particles

個々の粒子の鉛同位体比分析への二次イオン質量分析法の応用

江坂 文孝  ; 渡部 和男; 間柄 正明  ; 臼田 重和

Esaka, Fumitaka; Watanabe, Kazuo; Magara, Masaaki; Usuda, Shigekazu

二次イオン質量分析法による個々の粒子の鉛同位体比測定の有効性を調べるために、都市粉塵,自動車排出粒子,石炭フライアッシュの3種類の試料中の鉛同位体比を測定した。電子線プローブマイクロアナライザーで鉛含有粒子を特定した後、二次イオン質量分析法でPb/Pb, Pb/Pbを測定した。その結果、測定したすべての粒子で相対標準偏差1.6%以下での測定が可能であり、それぞれの試料で、同位体比の違いを明らかにすることができた。

The capability of secondary ion mass spectrometry (SIMS) for lead isotope ratio measurements of individual particles has been demonstrated by measuring lead-containing particles in three kinds of environmental certified reference materials (CRMs): urban particulate matter, vehicle exhaust particulates and coal fly ash. The isotope ratios of Pb/Pb and Pb/Pb for the individual particles on the carrier were determined by SIMS. The relative standard deviations of the lead isotope ratios were less than 1.6 % for all particles measured. It was demonstrated that the results of the lead isotope ratios were clearly distinguished among the three samples. Moreover, the particles in the vehicle exhaust particulate sample were classified into two groups according to lead isotope ratios. The results indicated that the present SIMS technique can provide detailed information with regard to the origin and the transportation of individual particles.