Optimizing the Analysis of Volatile Organic Compounds
Optimizing the Analysis of Volatile Organic Compounds
Optimizing the Analysis of Volatile Organic Compounds
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42<br />
Figure 41A.<br />
Analytes listed in EPA Method 601/602 can be separated in 20 minutes by an Rtx ® -VGC / Rtx ® -502.2 column pair.<br />
Rtx ® -VGC 75m, 0.45mm ID, 2.55µm (cat.# 19409)<br />
Innovations at Work<br />
Partial, quantifiable separation <strong>of</strong><br />
2-chloroethyl vinyl e<strong>the</strong>r (peak 22).<br />
Fastest analysis (20 min.) for EPA<br />
Method 601/602.<br />
3<br />
PID ELCD<br />
min. 5 10 15 20<br />
1. dichlorodifluoromethane<br />
2. chloromethane<br />
3. vinyl chloride<br />
4. bromomethane<br />
5. chloroethane<br />
6. trichlor<strong>of</strong>luoromethane<br />
7. 1,1-dichloroe<strong>the</strong>ne<br />
8. methylene chloride<br />
9. trans-1,2-dichloroe<strong>the</strong>ne<br />
10. methyl tert-butyl e<strong>the</strong>r<br />
11. 1,1-dichloroethane<br />
12. bromochloromethane (SS)<br />
13. chlor<strong>of</strong>orm<br />
14. carbon tetrachloride<br />
15. 1,1,1-trichloroethane<br />
16. benzene<br />
17. 1,2-dichloroethane<br />
18. fluorobenzene (SS)<br />
19. trichloroe<strong>the</strong>ne<br />
www.restekcorp.com<br />
7<br />
9<br />
10<br />
16<br />
18 19<br />
24<br />
22<br />
23<br />
suggested surrogates: peaks 12, 18, 31, & 38<br />
25<br />
26<br />
29<br />
30<br />
31<br />
35 36<br />
37<br />
38<br />
20. 1,2-dichloropropane<br />
21. bromodichloromethane<br />
22. 2-chloroethyl vinyl e<strong>the</strong>r<br />
23. cis-1,3-dichloropropene<br />
24. toluene<br />
25. tetrachloroe<strong>the</strong>ne<br />
26. trans-1,3-dichloropropene<br />
27. 1,1,2-trichloroethane<br />
28. dibromochloromethane<br />
29. chlorobenzene<br />
30. ethylbenzene<br />
31. 1-chloro-2-fluorobenzene (SS)<br />
32. brom<strong>of</strong>orm<br />
33. 1,4-dichlorobutane (SS)<br />
34. 1,1,2,2-tetrachloroethane<br />
35. 1,3-dichlorobenzene<br />
36. 1,4-dichlorobenzene<br />
37. 1,2-dichlorobenzene<br />
38. 4-bromo-1-chlorobenzene (SS)<br />
Acknowledgement: Finnigan 9001 GC, µGold Tandem<br />
Photoionization/HALL ® 2000 Electrolytic Conductivity Detector provided<br />
courtesy <strong>of</strong> Thermo Finnigan GC & GC/MS Division, 2215 Grand<br />
Avenue Pkwy, Austin, Texas 78728<br />
GC_EV00420<br />
1<br />
2<br />
3<br />
4<br />
5<br />
6<br />
7<br />
8 9<br />
11<br />
12<br />
13<br />
14<br />
15<br />
17<br />
19<br />
20 21<br />
18<br />
Primary column: 75m, 0.45mm ID, 2.55µm Rtx ® -VGC (cat.# 19409)<br />
Confirmation column: 75m, 0.45mm ID, 2.55µm Rtx ® -502.2 (cat.# 10986)<br />
Conc.: 10ppb in 5mL <strong>of</strong> RO water<br />
Concentrator: Tekmar LSC3100 Purge and Trap<br />
Trap: Vocarb 3000<br />
Purge: 11 min. @ 40mL/min.<br />
Dry purge: 1 min. @ 40mL/min.<br />
Desorb preheat: 245°C<br />
Desorb: 250°C for 2 min.<br />
Bake: 260°C for 8 min.<br />
Interface: direct connection from concentrator to column<br />
Transfer line: 0.53mm ID Silcosteel ® tubing (cat. #70045)<br />
Gas chromatograph: Finnigan 9001<br />
Carrier gas: helium @ ~10mL/min. constant pressure<br />
Adjust dichlorodifluoromethane to a retention<br />
time <strong>of</strong> 2.47 min. @ 40°C.<br />
Oven temp.: 40°C (hold 2 min.) to 58°C @ 4°C/min. to<br />
90°C @ 10°C/min. (hold 5 min.) to 220°C @<br />
40°C/min. (hold 5 min.)<br />
Detectors: µGold Tandem PID/Hall 2000 ELCD<br />
PID: makeup 7mL/min., purge 7mL/min., set @<br />
0.35mV base temp: 200 C.<br />
Hall 2000 ELCD: RxnGas 25mL/min., Rxn Temp. 940 C,<br />
propanol flow 470 L/min.<br />
22<br />
23<br />
25<br />
26<br />
27<br />
28<br />
29 31<br />
32<br />
35<br />
37<br />
34<br />
min. 5 10 15 20<br />
Standard cat.#<br />
502.2 mix#1 30042<br />
624 cal mix #2 30021<br />
624 cal mix #3 30022<br />
MTBE 30402<br />
1,4-dichlorobutane 30227<br />
Client compound lists might match <strong>the</strong> compound list in Method 601/602, but <strong>the</strong> calibration criteria and low detection limits <strong>of</strong> Method<br />
8021 are enforced. Figures 41A & B illustrate common compounds analyzed by GC/PID-ELCD, along with 2-chloroethyl vinyl e<strong>the</strong>r. The<br />
starting temperature is 40°C, and <strong>the</strong> analysis time is 20 minutes. An Rtx ® -502.2 column is a good choice for this analysis because it exhibits<br />
good resolution for 2-chloroethyl vinyl e<strong>the</strong>r.<br />
33<br />
Standard cat.#<br />
fluorobenzene 30030<br />
1-chloro-2-fluorobenzene 30040<br />
4-bromo-1-chlorobenzene 30230<br />
bromochloromethane 30225<br />
36<br />
38