N. Gungor et al., DETERMINATION OF TRACE-ELEMENTS BY INSTRUMENTAL NEUTRON-ACTIVATION ANALYSIS IN ANATOLIAN BENTONITIC CLAYS, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 142(4), 1998, pp. 555-560
Instrumental Neutron Activation Analysis (INAA) was carried out for th
e determination of trace elements in nonswelling type bentonitic clays
. Samples were irradiated in Triga Mark II type of reactor at the Nucl
ear Institute of Technical University of Istanbul. Irradiation was per
formed in two steps for ''short and long lived'' isotopes. The gamma s
pectra of short lived isotopes were interpreted with respect to Al, Ca
, Mg, Na, K, Ti, Mn, V qualitatively and that of long lived isotopes w
ith respect to Sc, Cr, Br, Sb, Cs, La, Ce, Sm, Yb, Hf quantitatively.
The relative richness of the trace elements (Al, Ti, Ca, Mg, Na, K) ob
served in the Sampo 90 program was obtained using Atomic Absorption te
chnique by normalizing its value to that of sodium. The silicon conten
t of samples was determined by gravimetry. The results indicated that
Sample I contained relatively higher amount of REE, Sb, Ca and Na than
Sample II. The amount of Sc, Cr and Br were about similar in both sam
ples. Concentrations of La, Ce, Sm and Yb are higher than REE abundanc
es found in all natural waters. These results suggest that Ca-bentonit
e samples are representative of primary deposition environment. In add
ition, the Sc content of both the samples indicates that Ca-bentonite
deposits originated from continental crust. The relatively high amount
of REE might bring about porosity problems in the use of Ca-bentonite
in cement and concrete production. (C) 1998 Elsevier Science B.V. All
rights reserved.