@article{oai:kanazawa-u.repo.nii.ac.jp:00010175,
 author = {中西, 孝 and Nakanishi, Takashi},
 journal = {Fresenius' Zeitschrift für Analytische Chemie},
 month = {Jan},
 note = {The demand for powdered quartz with low alpha -radioactivity has been increasing in the field of manufacturing semiconductor memory device packages. In this work, the determination of uranium in powdered high-purity quartz samples was studied using a simplified fission track procedure in which ∼ 0.5 g each of sample and a fission track detector (synthetic quartz glass plate, uranium impurity ∼ 0.04 ppb) were loaded in a polyethylene capsule and irradiated with a thermal neutron flux of ∼ 1017 cm-2. An easy procedure was also employed for chemical etching of fission tracks. All measurements of uranium concentration in the samples were made on a relative basis by comparing the unknown track densities to that measured for NBS glass SRM 617. The reliability was established for the present determination of uranium down to ∼ 0.1 ppb. The concentrations of uranium in powdered quartz samples studied in this work were in a range from 7.9 down to 0.12 ppb. © 1987 Springer-Verlag.},
 pages = {491--494},
 title = {Determination of uranium in powdered quartz at ppb level by fission track method},
 volume = {327},
 year = {1987}
}