Table 8. (cont'd)
TNT (mg/kg)
On-site
On-site
Sample
(colorimetric)
(EIA)
Acetone-HPLC
Method 8330
D9Comp a
1.7
<0.5
<0.3
<0.3
D9Comp b
1.9
<0.5
<0.3
1.0
D10A
<1
<0.5
<0.3
<0.3
D10AA 1
<1
<0.5
<0.3
<0.3
D10AA 2
<1
<0.5
<0.3
<0.3
D10B
<1
<0.5
<0.3
<0.3
D10C
<1
<0.5
<0.3
<0.3
D10D
<1
<0.5
<0.3
<0.3
D10Comp a
<1
<0.5
<0.3
<0.3
D10Comp b
<1
<0.5
<0.3
<0.3
C4A
13
215
11
7.5
C4AA 1
6.5
4.05.0
5.6
6.5
C4AA 2
4.8
4.05.0
3.9
2.6
C4B
5.6
4.05.0
4.3
16
C4C
11
4.59.0
15.9*
4.8
C4CC 1
3.0
4.05.0
2.5
4.3
C4CC 2
1.7
4.05.0
3.4
4.7
C4D
23
1215
20
10
C4Comp a
19
4.516
16
3.9
C5A
19
1215
18
0.8
C5B
1.4
1.53.0
1.9*
4.8
C5C
<1
0.51.5
<0.3
0.4
C5D
2.6
3.04.0
2.6*
73
C5Comp a
4.8
4.05.0
4.3
6.2
C5Comp b
1.6
0.51.5
1.2
4.9
* Data from GCECD analysis.
Table 9. Apparent false positives and false negatives relative to Method 8330 results
for TNT.
Apparent false positives
Apparent false negatives
No. pos. by†
Detection limit
No. pos.*
No. confirmed
No. detected
Method
(mg/kg)
on-site
Method 8330
Method 8330
on-site
EnSys
1.0
48
41
36
32
Colorimetric
D TECH
0.5
44
38
45
35
Immunoassay
Acetone HPLC
0.3
49
42
52
42
* Concentration above detection limit of method.
† Concentration by Method 8330 was above the detection limit of associated confirmatory
method
ent false negatives. To put this in perspective,
In terms of false positive analysis, the EnSys
though, 52 samples gave Method 8330 concentra-
method resulted in a positive response for 48
tion estimates above the 0.3-mg/kg detection limit
samples. Of these, 41 were confirmed positive by
of the acetone HPLC laboratory method, which
Method 8330 while seven were non-detects. In a
used the same acetone extracts as used by the
similar manner, the D TECH method had 44 posi-
EnSys and D TECH methods. Of these, 10 were
tive responses and 38 were confirmed by Method
classified as apparent false negatives by acetone
8330, while six were non-detects. The acetone
HPLC.
HPLC method resulted in 49 positive responses
21
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