Title
|
|
|
|
Sequential determination of a combined and pure -emitter by gamma and liquid scintillation counting: application to the transport of metals across fish gills
|
|
Author
|
|
|
|
|
|
Abstract
|
|
|
|
A combined gamma scintillation/liquid scintillation technique for the sequential determination of two radioactive tracers is described. The method was developed using a combined gamma/beta-emitter (Co-57) and a pure beta-emitter (Ca-45). First, the Co-57 radioactivity was determined by counting the samples in a gamma scintillation analyzer in the energy region 80-165 keV. Next, the samples were counted in a liquid scintillation analyzer. Only one energy region was used to count both isotopes to maximize the counting efficiencies. From the difference between quenched and unquenched beta-spectra, the counting region was set from 0 to 256 keV. The counting efficiency was related to a quench-indicating parameter (tSIE) for both nuclides by fitting a rectangular hyperbola to the quench data. By subtracting the Co-57 counts from the observed counts in the total window, Ca-45 dpm values were obtained. It is shown that the method presented gives reliable and consistent results. The recoveries of both isotopes are independent of the quench level in a large tSIE range, although five times more radioactivity is required for Ca-45 than for Co-57 to obtain accurate and reproducible results. The method has been used to study mechanisms of metal transport across biological interfaces. (C) 1995 Academic Press, Inc. |
|
|
Language
|
|
|
|
English
|
|
Source (journal)
|
|
|
|
Analytical biochemistry. - New York, N.Y.
|
|
Publication
|
|
|
|
New York, N.Y.
:
1995
|
|
ISSN
|
|
|
|
0003-2697
|
|
DOI
|
|
|
|
10.1006/ABIO.1995.1012
|
|
Volume/pages
|
|
|
|
224
:1
(1995)
, p. 92-99
|
|
ISI
|
|
|
|
A1995QB30600012
|
|
Full text (Publisher's DOI)
|
|
|
|
|
|
Full text (publisher's version - intranet only)
|
|
|
|
|
|