TEL by Vocarb 3000 P&T vs direct injection
Posted: Mon May 18, 2026 10:37 pm
I need a suggestion for a proper trap to use for TetraEthylLead [TEL] if one exists. I can get 739,000 counts for 160 ppb counts by direct injection: I get a nice peak with masses clustered at 207, 237, 266, 295, and a tiny molecular peak at 324. For reference, 70 ppb fluorobenzene is 4 million.
Instrument is an old HP 5971/5890 II with diffusion pump and an upgraded 5972 top board and mainboard. Running 20m x 0.18mm ID x 1um coating DB-VRX column. Purge gas is LN2; purge temperature 70C; Archon autosampler; Tekmar 3001 P&T; desorbing at 150C for 1 minute; trap is vocarb 3000. Valve body and transfer line 150C, inlet 150C. Source ~170C. Slow T ramp from 40C to 230C; TEL comes out at 16.8 minutes.
If I do this via the P&T I get a much smaller peak of 268,000 counts for the same 4uL of 200 ppm TEL standard. For reference 70 ppb fluorobenzene is 5 million.
Instrument is an old HP 5971/5890 II with diffusion pump and an upgraded 5972 top board and mainboard. Running 20m x 0.18mm ID x 1um coating DB-VRX column. Purge gas is LN2; purge temperature 70C; Archon autosampler; Tekmar 3001 P&T; desorbing at 150C for 1 minute; trap is vocarb 3000. Valve body and transfer line 150C, inlet 150C. Source ~170C. Slow T ramp from 40C to 230C; TEL comes out at 16.8 minutes.
If I do this via the P&T I get a much smaller peak of 268,000 counts for the same 4uL of 200 ppm TEL standard. For reference 70 ppb fluorobenzene is 5 million.