centration was very low (less than 2 g/g) and
RSDs of 3.3 and 4.9%, respectively, indicating that
TNB was the compound present at the highest
field homogenization was excellent and the preci-
concentration (about 10 g/g). TNB reacts to the
sion of the on-site test is equivalent to that of the
EnSys reagent identically as does TNT with simi-
lab method under these circumstances.
lar absorptivity and is not distinguishable from
ANOVA was conducted on the data from dis-
TNT using on-site colorimetric analysis. In addi-
crete sample analysis, both with and without log-
tion to TNB, 2,4-DNT was also present in these
transformation, but as with location 4, transfor-
samples at significant concentrations, but consid-
mation was unnecessary (Table 5b). The F ratios
erably lower than TNT, and it also reacts with the
for field and lab results were 1061 and 282, re-
EnSys reagent and contributes to the absorbance
spectively, meaning that discrete samples from
at 540 nm. The TNT concentrations estimated from
location 5 were significantly different from one
the screening test for this location (about 12 to
another at greater than the 99.9% confidence level.
almost 400 g/g) agree reasonably well with the
LSD tests showed that all seven samples were
concentrations of total nitroaromatics (sum of
significantly different from one another. Partition-
TNT, TNB and 2,4-DNT) obtained from labora-
ing the variances into analytical and sampling
tory analysis.
components gave estimates for analytical stan-
dard deviation of 5.3 and 11.0 g/g for the on-site
Duplicate on-site and laboratory analyses for
soils from location 5 agree very well with mean
and lab methods, respectively, while estimates
Table 5. Results from sampling location 5, Hawthorne AAP site.
a. Analytical results.
TNT on-site
Laboratory analysis (g/g)
analysis
(g/g)
Sample
TNB
TNT
2,4-DNT
Total
Discrete samples
1a
127
33.5
63.8
27.7
125
1b
125
32.8
48.2
27.3
108
2a
116
52.8
214
2.6
269
2b
103
52.8
210
10.6
273
3a
379
57.0
286
14.7
358
3b
366
61.7
312
17.7
391
4a
59.1
14.6
37.6
1.9
54.1
4b
56.0
15.5
34.0
1.8
51.3
5a
12.4
10.0
1.9
1.0
12.9
5b
13.3
10.7
1.7
--
12.4
6a
170
17.2
222
12.2
251
6b
173
16.8
207
11.7
236
7a
240
40.4
53.4
15.4
109
7b
245
37.6
48.4
14.4
100
mean
156
168
Composites
C1
129
32.1
145
11.4
189
C2
137
32.1
144
9.2
185
C3
116
32.4
150
11.2
194
C4
138
34.1
163
10.8
208
C5
139
34.5
149
10.9
194
C6
147
33.7
142
11.5
187
C7
170
33.5
152
11.8
197
mean
139
193
std. dev.
16.6
7.72
19