Multielement determination in marine sediment reference material by instrumental neutron activation analysis

Multielements in NIES (National Institute for Environmental Studies of Japan) certified reference material No. 12 marine sediment were determined by instrumental neutron activation analysis (INAA). Six portions of the marine sediment reference material (ca. 50 ∼ 430 mg) were irradiated successively, at first for a short time (30 s) at a thermal neutron flux of 1.5 x 1012 n cm-2s-1 and then for a long time (12 h) at a thermal neutron flux of 1.7 x 1012 n cm-2s-1 in the Rikkyo University Research Reactor. After a suitable decay-period, these irradiated portions were measured by three γ-ray spectrometric methods; a conventional counting method using a coaxial Ge detector, and an anticoincidence and a coincidence counting method using a coaxial Ge detector and a well type NaI(Tl) detector. γ-Ray spectra obtained were analyzed by a peak-fitting procedure using a GAMA system. Corrections for overlapping interference peaks and interfering nuclear reactions were applied to the spectral data. Concentrations of 54 elements (Na, Mg, Al, Si, Cl. K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Zr, Mo, Ag, Cd, In, Sn, Sb, I, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Au, Hg, Th, U) were determined by these counting methods. (author)