Figure7
TLCspectrum for aTO-14/TO-15ambient air analysis.
Phone: 800-356-1688 or 814-353-1300
11
tor to each“unknown”analyte peak area to get the reporting limit concentra-
tion of the“unknown” in the analysis (typically in ppbv). If you have diluted
the canister to get a positive pressure, however, youmust apply the dilution
factor to the concentration values. This is done bymultiplying the reporting
limit by the dilution factor.
VII.Cleaning thePassiveSamplingTrain
The cleanliness of the sampling train is critical to collecting accurately repre-
sentative samples. Practices followed for cleaningpassive sampling equipment
between uses range from purging the sampling pathway with humidified
nitrogen or air formany hours toheating the pathway during a purge to dis-
assembling each component, sonicating thepieces in solvent, andovenbaking
the pieces prior to re-assembly. Themost suitablemode of cleaning depends
on the concentrations of analytes of interest, and contaminants, in the previ-
ous sample collected.
The particle filtermust be thoroughly cleaned betweenuses.Disassemble the
filter, then remove the larger particles from the frit by blowing particle-free
nitrogen through the frit from theoutlet surface toward the inlet surface.After
the larger particles are removed sonicate or rinse the filter parts inmethanol,
thenbake theparts inanovenat 130°C to removeany residual organicvapors.
The critical orifice and flow controller can be cleaned in either of two ways.
The firstmethod is to disassemble the flow controller and clean all themetal
partswithmethanol. Thiswill remove any highboiling compounds that have
condensedonto thewettedareasof thecontroller.Heat thecleanedparts inan
ovenat 130°C to remove residual organicvapors.Donot sonicate in solventor
bakeanyof thenon-metallicparts, suchasO-rings; theywill bedamageddur-
ing these steps. Do not rinse the vacuum gauge withmethanol. The vacuum
gaugemay be heated, but donot exceed 80°C; higher temperatureswill dam-
age the face and the laminated safetyglass lens.Heating to80°Cwill not affect
themechanical operationof the spiral bourdon tube in the vacuum gauge.
Rtx
®
-1 60m, 0.32mm ID, 1.0µm (cat.# 10157).
Sample:
200mL of 10ppbvTO-15 standard (cat.# 34436), injected intoTO-Can
™
canister and humidified to 70%RH.
Concentrator:
Nutech 3550 Preconcentrator
200mL of sample concentrated at 160°C, thermally desorbed at 150°C, and cryofocused at 185°C.
Oven temp.:
30°C (hold 4min.) to 175°C@ 9°C/min. to 220°C@ 40°C/min.
Carrier gas:
helium@ 1.2mL/min.
Det.:
Agilent 5971MS
Scan range:
35-265amu
4 5
6
7 8
9
10 11
12
13 14 15 16 17 18 19 20 21 22 23 min.
1
3
4
5
6
7
8
9/10
11
12
13
14
15
16
17
18
19
20
21
22/23
24
25
26
27
28
29
30
31
32
33
34
35/36
37
38
39
40
41 42
43 44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
BFB
GC_EV00379
2
1. dichlorofluoromethane
2. chloromethane
3. dichlorotetrafluoroethane
4. vinyl chloride
5. 1,3-butadiene
6. bromomethane
7. chloroethane
8. bromoethene
9. acetone
10. trichlorofluoromethane
11. isopropyl alcohol
12. 1,1-dichloroethene
13. methylene chloride
14. 3-chloropropene
15. carbon disulfide
16. Freon
®
TF
17.
trans
-1,2-dichloroethene
18. 1,1-dichloroethane
19. methyl
tert
-butyl ether
20. methyl ethyl ketone
21.
cis
-1,2-dichloroethene
22. bromochloromethane (IS)
23.
n
-hexane
24. chloroform
25. tetrahydrofuran
26. 1,2-dichloroethane
27. 1,1,1-trichloroethane
28. benzene
29. carbon tetrachloride
30. cyclohexane
31. 1,4-difluorobenzene (IS)
32. 1,2-dichloropropane
33. bromodichloromethane
34. trichloroethene
35. 1,4-dioxane
36. 2,2,4-trimethylpentane
37.
n
-heptane
38.
cis
-1,3-dichloropropene
39. methyl isobutyl ketone
40.
trans
-1,3-dichloropropene
41. 1,1,2-trichloroethane
42. toluene
43. methyl butyl ketone
44. dibromochloromethane
45. 1,2-dibromoethane
46. tetrachloroethene
47. chlorobenzene-d5 (IS)
48. chlorobenzene
49. ethylbenzene
50.
m
/
p
-xylene
51. bromoform
52. styrene
53. 1,1,2,2-tetrachloroethane
54.
o
-xylene
55. 2-chlorotoluene
56. 4-ethyltoluene
57. 1,3,5-trimethylbenzene
58. 1,2,4-trimethylbenzene
59. 1,3-dichlorobenzene
60. 1,4-dichlorobenzene
61. 1,2-dichlorobenzene
62. 1,2,4-trichlorobenzene
63. hexachlorobutadiene
