I am trying to resolved gases using a 0.53mm ID column packed column. Being somewhat new to GC I only had used previously capillary column. I would like to apply a flow of 6mL/min (as per supplier suggestions) but no signal is obtained when I try it. Are there any solutions to this? Since this is university works, the budget for new columns is non-existant. I am using an Agilent GC/MS.
Thanks for your help,
By Anonymous on Tuesday, August 3, 2004 - 03:23 pm:
What Agilent MSD do you have? 5971 and 5972 can't handle large carrier flows, the 5973 can handle more. So with 0.53mm column you may need to use a flow splitter, I'd say purchase the correct column and do it right.
By good luck on Tuesday, August 3, 2004 - 10:53 pm:
Hi Jean Philippe,
I'm not sure to understand your problem but the thing I can tell you is that we have a 6890 with a 5973N and columns with a 0.32mm ID at least, never more (usually 0.25mm ID). About the flow, agilent recommends for 5973 and 5972 never more than 2ml/mn for a diffusion pump and never more than 4ml/mn for a turbo pump (the turbo seemms to be available only with the 5973). Actually, the flow seems to depend only on the pump you use. Good luck with agilent instrument, you'll need it (MSD Chem's one of the worst things I've ever worked with)
By JPL on Wednesday, August 4, 2004 - 05:22 am:
I am working with the 5973 (with the turbo pump) so it seems that I will not be able to use high flow rate. I'll try to get a capillary column which should work better.
Thanks for the encouragement for the MSD software, definetely one of the worst software I ever used.
By Anonymous on Wednesday, August 4, 2004 - 08:16 am:
I'm not a computer guy, and learned how to use that mouse-thing in 1990 with HP MSD Chemstation (Windows 386, before Windows 3.0, on a 16 MHz 386 computer), and I don't have too many issues with it, except for the quantitation parts. Even the register parts for merging chromatograms aren't that bad once I learned them. We still run that system on Windows 3.1, had one MSD circuit board go out in 14 years, awfully good reliability.
By Mark on Wednesday, August 4, 2004 - 02:36 pm:
I have one of the 5973 Inert systems from Agilent (has the performance turbo option) and it will work with the higher flow rates. Agilent says you can use it with a 0.53 mm column, just reduce the flow rate to abuot 2.5 to 3 mL/min.
By GC user on Wednesday, August 4, 2004 - 06:59 pm:
If I was using a 0.53 column with an Agilent I would use an open split interface with a 1 meter section of 0.25 mm deactivated tubing to reduce the flow to a more appropriate level.
By Karl Kuhlmann on Thursday, August 5, 2004 - 11:51 am:
I tried a 0.53x105M Rtx-1 in my new Shimadzu GCMS QP-2100 and was able to work with flows up to about 4 mL/min. This instrument has a 300 lpm turbo at the source and a 70 lpm turbo at the rods, so the vacuum is better than most of the earlier 597x series I have used. There was one wierd thing, though. I do ultra-trace analysis, and the baseline had severe dips before and after most peaks. After talking with Shimadzu, we finally figured out that it was probably a result of the source electronics trying to keep the ion current constant and not being able to at the high flows. I switched to a 0.32 at 2 mL/min and have had no further problems. I am able to run a 5:1 split and scan through the solvent peak.