Table 7 (cont'd). Results from sampling location 7, Volunteer
AAP site.
b. Statistical analysis of TNT concentrations (g/g) for discrete
and composite samples.
Discrete samples
On-site analysis
Laboratory total
Sample
Mean
Mean of logs
Mean
Mean of logs
1
115,000a†
5.058a
112,000a
5.047a
2
28,000b
4.447c
55,200d
4.742d
3
51,700ab
4.713b
72,700cd
4.861c
4
110,000a
5.034a
104,000ab
5.017ab
5
92,900a
4.968a
101,000ab
5.004ab
6
84,800a
4.917a
101,000ab
5.004ab
7
112,000a
5.048a
79,100bc
4.891bc
†
Numbers designated with the same letter are not significantly different at
the 95% confidence level.
ANOVA for on-site and lab analyses
Untransformed
On-site
Lab
F ratios
7.80**
14.3**
Error MS
285,585,544
58,980,714
Least sign. diff.
39,960
18,160
Analysis s
16,900
7,680
Sampling s
31,200
19,800
(s = standard deviation)
Linear correlation analysis for on-site analysis vs. lab analysis
(r = correlation coefficient)
Slope
Intercept
r
untransformed, non-zero intercept
1.319
32,833
0.815
untransformed, zero intercept
0.967
0
0.784
Results of paired t-tests for on-site vs. lab results
Means of seven discrete samples, t = 0.56 (NS)
Composite samples
On-site analysis
Laboratory total
n
7
7
mean value
57,000
107000
standard deviation
2600
9230
RSD
4.56%
8.63%
ANOVA comparing on-site and lab analyses
F ratio = 190***
* Significant at the 95% level
*** Significant at the 99.9% level
** Significant at the 99% level
NS Not significant at the 95% level
The results from analysis of composite samples
from analysis of the two composites should pro-
from locations 7 and 7R are particularly interest-
duce similar results. In fact, nearly identical esti-
ing (Tables 7b and 7d). Since the two sampling
mates of concentration were obtained by both the
laboratory and on-site analyses: 57,000 g/g vs.
locations were only 15 cm apart, either set of
55,200 g/g for the field and 107,000 g/g for
samples could be used to characterize the site. If
composite sampling is a useful approach, results
both from the lab.
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