Lead concentration in rock, shell and algae was determined by graphite furnace atomic absorption spectrometry (GFAAS), prior to this lead was separated using an anion exchange column of HBr media. To prevent lead contamination during handling and dissolution, the analysis was performed in a clean laboratory and clean bench, and acids used in the procedure were purified by redistillation with quartz and Teflon wares. The sample was completely decomposed with HF (not used for shell and muscle), HNO_3 and HClO_4, and dried. The sample was dissolved in 0.5 M HBr, spiked with ^<212>Pb and was passed through a column of Bio Rad AG 1-X8 100〜200 mesh (4mm i. d.×4 cm h). Lead retained on the column was eluted with 6 M HC1 after washing the column with 0.5 M HBr. The column yield of the purified solution was measured by ^<212>Pb activity and then the solution was subjected to lead concentration measurement by GFAAS. Lead concentration in the sample was deter- mined from the relationship between sample weights and total lead amounts obtained from more than 3 analyses of the same sample using the method of least-squares fitting. The lead values obtained for standard materials, JA-1, JB-1, JB-2, JB-3, JG-1, JGb-1, JR-1, JR-2 of GSJ rocks and of NIES SRM No.1 Pepperbush were 5.7, 7.3, 5.1, 5.7, 27.1, 1.6, 19.1, 23.7 and 5.3 ppm, respectively. Marine samples contained traces of lead : 27 ppb fresh weight for algae (Eisenia bicyclis), 96 ppb for abalone shell (Haliotis discus) and 4.5 ppb f. w. for abalone muscle.
