Table 2: Results of retainability tests. Front, Back1, and Back2 were the front, 1st backup and 2nd backup tubes in series. Amounts of TMSOH in three tubes were expressed as the percentages of the initial amount spiked to the front tube.
Amount (ng)
Vol (L)
Flow
Dual-bed tubes
Single-bed tubes
Front (%)
Back1 (%)
Back2 (%)
Front (%)
Back1 (%)
Back2 (%)
10
1
N2
98.2
1.1
0.7
91.6
4.4
3.9
10
5
N2
96.0
0.7
3.3
66.6
28.7
4.8
10
10
N2
99.4
0.4
0.2
78.7
20.8
0.5
10
20
N2
97.8
1.0
1.2
68.5
27.1
4.5
200
1
N2
99.5
0.5
0.1
94.3
5.7
0.0
200
5
N2
98.9
0.3
0.8
24.6
34.0
41.4
200
10
N2
97.8
1.1
1.2
18.4
35.0
46.7
200
20
N2
99.5
0.4
0.1
23.0
38.5
38.5
200
20
Air
99.7
0.3
n.a.
35.8
64.2
n.a.
200
20
Air
98.4
1.6
n.a.
40.9
59.1
n.a.
Notes: aFlow matrix: the gas blown through tubes in retainability tests. n.a.: not available.