Abstract
The applicability of inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) has been investigated to the discrimination of low-alpha lead raw materials for electronics material. The experimental conditions for ICP-QMS were first optimized to improve the precision of isotope ratio measurement of lead materials. The lead isotope ratios of NIST SRM981 measured by an ICP-QMS under the optimized conditions agreed with those obtained by high precision mass spectrometers, thermal ionization mass spectrometer or multiple collector inductively coupled plasma mass spectrometer within the range of statistical errors. The relationship between the isotope ratios and alpha dose rates measured for six types of lead raw materials in various quality produced by different refining methods revealed that the leads examined here were divided into four groups. The low-alpha lead raw material showed a peculiar isotope ratio and was found to be discriminable by ICP-QMS.
