Table 8. Results of holding-time study using three fortified ground waters.
Concentration ( X S)**
(g/L)
Preserved
Analyte/matrix*
(pH 2.0)
Day 0
Day 3
Day 7
Day 14
Day 28
Day 64
53.1 1.39
51.4 0.30
51.3 0.41
35.2 0.20
18.4 0.22
7.9 0.04
TNB
1
No
51.8 0.69
51.2 0.07
56.7 1.96
53.9 0.30
53.5 0.47
51.8 0.56
Yes
52.4 0.58
52.3 0.49
54.7 0.18
45.2 0.51
33.8 0.93
16.5 1.20
2
No
52.8 1.56
52.0 0.10
54.9 0.13
54.0 0.35
54.6 1.42
53.4 0.62
Yes
53.6 0.62
52.5 0.09
53.4 0.54
42.2 0.85
20.7 0.68
4.2 0.60
3
No
52.7 0.81
52.9 0.04
55.6 0.15
54.8 0.46
56.6 0.26
54.7 0.16
Yes
42.5 1.17
39.2 0.02
29.0 0.28
13.9 0.58
7.2 0.01
3.0 0.13
tetryl
1
No
41.5 0.67
41.6 0.53
45.8 0.39
43.1 0.13
42.7 0.41
39.5 0.44
Yes
41.4 0.48
39.7 0.48
38.6 0.48
25.8 0.27
14.4 0.02
3.7 0.80
2
No
41.5 1.54
41.6 0.40
44.4 0.53
42.6 0.72
42.4 0.11
40.4 0.42
Yes
170.3 0.1
168.5 0.0
147.4 2.5
83.1 0.48
70.2 0.01
26.3 0.53
3
No
170.8 0.6
173.7 2.0
179.9 3.5
174.7 2.2
176.3 0.1
158.4 0.63
Yes
89.4 2.27
89.1 0.24
93.3 0.45
80.9 0.43
74.6 0.89
61.8 1.05
TNT
1
No
88.3 0.71
91.0 0.75
96.1 2.96
92.6 0.98
90.7 1.15
91.6 0.60
Yes
89.9 1.18
91.8 1.45
94.0 0.40
85.4 1.05
74.1 2.25
63.4 0.37
2
No
89.1 2.82
92.1 0.96
94.6 0.76
92.5 0.02
92.3 1.73
91.5 0.29
Yes
90.5 1.51
91.3 0.26
94.7 0.96
88.1 0.84
80.2 0.18
62.5 0.51
3
No
88.5 0.07
93.5 1.82
95.0 0.15
89.9 0.48
94.3 0.11
92.7 0.27
Yes
56.0 1.67
55.7 0.32
57.5 0.16
56.9 0.01
56.5 0.04
56.4 0.87
4-ADNT
1
No
55.3 1.29
45.2 0.47
39.6 0.22
34.8 0.16
35.0 0.31
31.1 0.10
Yes
55.5 0.94
55.7 0.23
57.0 0.46
56.5 0.17
54.6 1.13
54.5 0.42
2
No
56.2 1.69
45.9 0.32
41.0 0.71
36.1 1.56
32.7 1.00
29.8 0.14
Yes
54.3 2.07
51.1 2.79
55.8 1.80
54.9 0.28
53.4 0.38
54.5 0.25
3
No
54.6 0.46
47.8 1.85
45.2 0.52
41.4 0.76
40.9 1.02
38.7 0.15
Yes
* Matrix 1 = PT, matrix 2 = MW, matrix 3 = TR
** X = mean; S = standard deviation
To determine if these losses could be eliminated
acidified samples compared with unacidified. Pre-
using Teflon cap liners, a study was conducted as
served and unpreserved samples were prepared
follows. Reagent-grade water was fortified with
and treated as described for the previous study,
TNT, NB, the three nitrotoluenes, and the two
except that only duplicates were analyzed for each
DNTs. Samples were stored in an inverted posi-
storage time. The results of this study are shown
tion, under refrigeration, and analyzed after 7, 14,
in Table 8.
28, and 64 days. No measurable losses were ob-
60
served. Thus, the losses for this group of analytes
would have been eliminated if vials using
Teflon cap liners had been used in the holding-
time study.
40
Holding-time study using
pH 2 stabilization for
fortified groundwaters
Since preservation by acidification to pH 2
was successful for most of these compounds in
Connecticut River water, an additional study was
20
Control
Acidified
groundwaters were fortified with TNB, TNT,
tetryl, and 4ADNT at the same initial concentra-
PT Groundwater
MW Groundwater
tions as used above. The concentration of tetryl
TR Groundwater
was inadvertently fortified at a higher concen-
0
tration for one groundwater matrix. We studied
20
40
60
Storage Time (days)
TNB, tetryl, and TNT because they were the least
Figure 14. Losses of TNB in acidified and unacidified
stable of those tested in the river water matrix.
groundwater samples as a function of storage time.
4ADNT was of interest because of its behavior in
16
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