ranged from 13.5 to 140 g/kg and 5.4 to 145 g/kg,
The discovery of RDX and TNT in a number of these
samples was not surprising since the 105-mm rounds
respectively. RDX was observed in only two of these
contain Composition B as the main charge. The fact
samples and the concentrations were low, 4.8 and 5.5
g/kg. Since the 105-mm rounds contain Composition
that 4-ADNT and 2-ADNT were found at concentra-
tions generally as high as that of TNT was unexpected,
B as the main charge, either RDX has preferentially
though, since we believe that the detonation forming
leached out of these craters, or the residues we find
this crater occurred only the previous day. The rapid
here were deposited from a TNT-containing round
formation of these transformation products from TNT,
instead and were not associated with the 105-mm rounds
however, is consistent with the half-lives observed for
that made these craters. The preferential leaching of
TNT in a recent report by Miyares and Jenkins (2000)
RDX from these recent craters would be somewhat
and some earlier work by Maskarinec et al. (1991) and
surprising since it is thought to dissolve slower than
Grant et al. (1993).
TNT from solid Composition B. On the other hand, once
The fifth area sampled appeared to be an old 155-
dissolved, soils have much less tendency to sorb RDX
mm crater that we guessed was several years old by the
than TNT and so it is possible that this is the explanation
vegetation growing within. Again, nine samples were
for the minimal presence of RDX in these samples.
collected in and around this crater; two composites from
The eighth area sampled was a crater formed by the
within the crater and a seven-sample wheel centered
detonation of a 60-mm mortar round that was estimated
on the crater as described for the previous crater sam-
to be about a year old (Table 8, samples 119120). Two
pled (Table 8, samples 8896). No explosives-related
composite samples were collected from within the crater
analytes were observed for the three samples collected
and TNT, 4-ADNT, and 2-ADNT were found in both.
Concentrations of 222 and 362 g/kg were found for
within the crater, but RDX, 4-ADNT, and 2-ADNT were
detected in all six of the samples collected around the
TNT, 30.0, and 38.1 for 4-ADNT, and 7.9 and 18.0 for
rim of the crater. Concentrations of RDX ranged from
2-ADNT. Since the main charge in 60-mm mortar
trace to 5.0 g/kg, 4-ADNT ranged from 5.4 to 20.6
rounds is 0.43 kg of Composition B, it is surprising
g/kg, and 2-ADNT ranged from 2.6 to 15.2 g/kg.
that we did not find RDX in this crater if these residues
were indeed due to the detonation of a 60-mm round.
TNT was also detected in four of the six samples with
concentrations ranging from 1.3 to 6.0 g/kg; 2,4-DNT
Perhaps the residues we observed in these samples actu-
was observed in two samples at 6.9 and 15.3 g/kg.
ally originated from a TNT-containing round such as a
155-mm artillery round instead, or RDX had leached
While detectable, all of these residues are present at
from this crater during the year since the detonation
very low concentrations and wouldn't have been detect-
had occurred.
able using SW-846 Method 8330. In addition, the main
The next series of samples was collected at various
charge for 155-mm rounds generally contains TNT, not
points throughout the range. These samples were taken
Composition B, and the RDX found in these samples
from various areas as described in Table 8 (samples
appears to have originated from a source other than a
5861, 8687, and 105106). Samples 58 and 59 were
155-mm detonation.
taken a short distance from an unidentified crater and
The sixth area of samples was a series of background
contained no measurable residue. Likewise, samples 60
samples collected in a wheel pattern within the range,
and 61 were taken near two very old craters and no
but not close to any visual crater (Table 8, samples 97
residues were detectable here either. Samples 86 and
to 103). Low levels of RDX, 4-ADNT, 2-ADNT, and
87 were collected next to more recent craters and low
TNT were observed in these samples, but concentra-
tions were always below 30 g/kg. These results indi-
concentrations of RDX, 4-ADNT, and 2-ADNT were
found in each. Finally, samples 105 and 106 were taken
cate that low concentrations of explosives residues are
from an area that had recently burned because of an
distributed in some places over fairly large areas even
illumination round, and again concentrations of RDX,
when no craters are observable, but it is impossible to
4-ADNT, and 2-ADNT were detectable.
identify a specific source.
The final samples collected from the artillery impact
Next we sampled a series of six craters that were
area were samples associated with a 155-mm round that
identified by our EOD team as recent 105-mm craters,
had undergone a low-order detonation (Table 9). This
probably formed from detonations within a week of
round was broken open and was still filled with the
sample collection (Table 8, samples 113118). Com-
unexploded main charge (Figure 18). This material was
posite samples from the inside walls of all six of these
sampled and the analysis indicated that it was 99.96%
craters were similar in that TNT, 4-ADNT, and 2-ADNT
2,4,6-TNT with a small percentage of the manufactur-
were the residues at highest concentration in each case.
TNT concentrations ranged from 59.2 to 1750 g/kg in
ing impurity, 2,4-DNT (0.04%). Concentrations of
2,4,6-TNT and its associated impurities and environ-
these samples; concentrations of 4-ADNT and 2-ADNT
22
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