tion declined from about 91 g/L to 13.4
100
g/L over 64 days. Concentrations of tetryl,
TNB, TNT, and DNB in the unacidified
RDX
samples dropped by 73%, 66%, 28%, and
17%, respectively, during the currently ac-
80
cepted holding time of seven days. Trans-
formation products from TNB, TNT, tetryl,
HMX
DNB, and 2,6-DNT were observed in
increasing concentrations as the concentra-
60
tions of the fortified analytes declined. For
TNB and TNT these transformation prod-
ucts were positively identified as the mono-
amino reduction products (McCormick et
al. 1977). In the case of tetryl, however, a
40
major transformation product was identi-
Control
fied as picrate ion, and lesser amounts of a
Acidified
transformation product thought to be due
to reduction of a nitro on the ring to amino
20
0
20
40
60
was also observed (Fig. 10). For DNB and
Storage Time (days)
2,6-DNT, the observed retention times of
Figure 8. Stability of HMX and RDX in fortified Connecticut
the transformation products were consis-
River water as a function of storage time for samples acidified to
tent with those expected for the monoamino
pH 2 or left unacidified.
transformation products, but we did not
have the authentic compounds available to
100
verify this assignment.
The third group of analytes included
TNT
4ADNT, 2ADNT, and 3,5-DNA. For solu-
tions where these analytes were fortified,
80
Control
there appeared to be a rapid step-drop in
Acidified
concentration for acidified samples within
the first several days, which differed sub-
60
stantially from their behavior in the
TNB
unacidified samples (Fig. 12). For acidified
samples, losses after seven days of storage
DNB
were 9%, 10%, and 23% for 2ADNT, 3,5-
40
DNA, and 4ADNT, respectively. After 64
TNT
days, losses were 9%, 12%, and 28% for the
same three compounds, indicating that no
20
DNB
significant additional loss had taken place.
Unacidified controls were somewhat more
stable initially and, after seven days of stor-
TNB
age, losses were 8%, 19%, and 3% for
0
20
40
60
2ADNT, 3,5-DNA, and 4ADNT, respec-
Storage Time (days)
tively, but these losses increased to 21%,
Figure 9. Stability of TNB, TNT, and DNB in fortified Con-
48%, and 12% for these compounds by day
necticut River water as a function of storage time for samples
64. Losses in the unacidified samples are
acidified to pH 2 or left unacidified.
presumably due to microbial transforma-
tion. We will discuss the losses in acidified
and 2 as a function of storage time (Fig. 10 and 11).
samples in more detail later.
In the worst case, tetryl declined when not acidi-
The fourth group of analytes includes the three
fied from about 41 g/L to "not detected" in less
isomers of nitrotoluene and nitrobenzene (2NT,
than 14 days. For TNB, the concentration in the
3NT, 4NT, NB). Concentrations for a given analyte
unacidified sample declined from about 53 g/L
declined slowly in acidified and unacidified solu-
to 0.7 g/L in 28 days, and for TNT the concentra-
tions at identical rates over the entire 56-day pe-
13
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