In all other cases wet chemistry
Table 10 presents a comparison
of all vegetation samples that showed
provided a more sensitive measure
positive
of 28] a concentration than did gamma
tam via gamma spectrometry.
This limited data set of five samples
spectrometry.
exhibits a mean MCL:LLL ratio of
increases in sensitivity were in the
0.95 + 22%, with no evidence for
range of 2.1- to 637-fold.
significant bias.
samples exhibited increases in the
Wet-chemistry
results are the simple averages of the
For vegetation samples,
Animal
range of 1.2- to 7,4-fold.
individual determinations by carrier
and carrier-free dissolution procedures.
WET-CHEMISTRY ANALYSES OF 241 VS
As indicated earlier in the
239,240
section on quality control, wetchemistry determinations of 24 sn
Pu
Results for 28 an and 239,240),
in vegetation may be systematically
were compared in those samples selected
low.
for wet chemistry.
Concentration
241
239
In addition, the large uncer-
tainties in the individual gamma
ratios of
measurements provide for a very
23942405, were calculated.
broad range of possible ratios.
Thus,
Am to
Pu and to
The
purposes of these computations were
there is no reason to conclude that
to examine any differences between
there is any significant difference
sample types
between wet chemistry and gamma
1 Am in
. vegetation.
,
spectrometry of
and sampling location (Bikini vs
(soil vs vegetation)
Eneu), and to determine mean ratios
-
Table 10,
Master log
number
01-0639-10
»
Comparison of a-PHA and gamma-spectrometric analyses for
vegetation (MCL vs LLL) .?
a-PHA
(MCL) dpm/g
Gamma spectrometry
(LLL), dpm/g
41am in
MCL:LLL
01-0641-10
0.44410
0.75419
0.34430%
1.3 432%
0.91455
0.82258
01-0803-10
4.9 +17
6.1 +20
0.80426
01-0829-10
0.43411
0.51456
0.84157
01~-0850-10
1.674 5.2
1.6 +30
1.0 +30
Average
a
All results are reported to a reference time of 1 January 1975
-~19-
|
0.951224
(001.0002,
75).