55
Method 624:
Previously, analysts used packed columns to performMethod 624, but now they generally use capillary chromatographic tech-
niques. The compound list inMethod 624 includes commonly analyzed aromatic and halogenated compounds inwastewater. This analysis
can be achieved onmany capillary columns; Figure 51 shows a 30m, 0.25mm IDRtx
®
-VMS column resolves the gaseous analytes to the
baseline.
Figure 51.
Gaseous analytes resolved to baseline on anRtx
®
-VMS column.
1. chloromethane
2. vinyl chloride
3. bromomethane
4. chloroethane
5. trichlorofluoromethane
6. 1,1-dichloroethene
7. methylene chloride
8.
trans
-1,2-dichloroethene
9. 1,1-dichloroethane
10. bromochloromethane
11. chloroform
12. carbon tetrachloride
13. 1,1,1-trichloroethane
14. benzene
15. pentafluorobenzene (surr.)
16. 1,2-dichloroethane
17. fluorobenzene (surr.)
18. trichloroethene
19. 1,2-dichloropropane
20. bromodichloromethane
21. 2-chloroethyl vinyl ether
22.
cis
-1,3-dichloropropene
23. toluene
24. tetrachloroethene
25.
trans
-1,3-dichloropropene
26. 2-bromo-1-chloropropane
27. 1,1,2-trichloroethane
28. dibromochloromethane
29. ethylbenzene
30. chlorobenzene
31. bromoform
32. 4-bromofluorobenzene (surr.)
33. 1,4-dichlorobutane
34. 1,1,2,2-tetrachloroethane
35. 1,3-dichlorobenzene
36. 1,4-dichlorobenzene
37. 1,2-dichlorobenzene
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00
30m, 0.25mm ID, 1.40 mRtx
fi
-VMS (cat#19915)
Conc.:
20 ppb in 5mLof ROwater
Concentrator:
Tekmar LSC-3000 Purge andTrap
Trap:
Vocarb 3000 (typeK)
Purge:
11min.@40mL/min.@ambient temperature.
Dry purge:
1min.@40mL/min. (MCS bypassed using
Silcosteel
fi
tubing)
Desorb preheat: 245 C
Desorb:
250 C for 2min. , Flow 10mL/min.
Bake:
260 C for 8min.
GC Interface: 1:10 split at injection port. 1mm ID sleeve.
GC:
HP6890
Oven temp.:
40 C (hold 4min.) to 95 C@24 C/min. (hold 3min.), to
210 C@40 C/min. (hold 6min.)
Carrier gas:
helium@~1mL/min. constant flow
Adjust dichlorodifluoromethane to a retention time of
2.54min.@40 C
Detector:
HP5973MSD
Scan range:
25-300amu
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17 18
19
20
21 22
23 24,25
27
26
28
29 30
31
32
33,34 35
36
37
GC_EV00425
