EZ:faast

[jburton]

Just wondering if anyones ever used the GC-FID kit from Phenomenex to analyze AA's??
I'm starting out and not real good at GC. Got a couple of questions......

Using an Agilent 6890A

[Radish]

I have used it. What is your question?

[jburton]

I am running it on an Agilent 6890 with FID. However the method that comes with the book shows the paraemeters using He as the carrier gas... Our instrument is set-up with H2....I have used a method translation software to convert it to H2 but my chromatography is not resembling the supplied chromatogram.
Any ideas on any factors?

I was running at 1.5mL/min for He and 32°C/min for my ramp from 110-320 now I am 1.2mL/min and 29°C/min....Is there anyhting else I should change such as inlet pressure or anyhting??

[Radish]

My instrument was set up for He, but I am sure other members of this board can assist you with the translation to H2 which has a higher velocity. Is your problem with inadequate peak resolution? If so, there is no reason you couldn't alter your temperature program to a slower ramp to see if that helps. Unfortunately with EZ the samples are simple to prepare but can be tricky to analyze, especially for a GC novice. I think you are in for some trial and error. Don't despair; it will make you a better chromatographer.

[jburton]

No I have good peak resolution it's just that my chromatogram doesnt look like the one from the manufacturer. I realize it will take some time to figure things but it's so frustrating!
I have my temperature ramp at 31°C/min does that sound about right? My ave. velocity is at 50cm/sec.

[Radish]

That temperature ramp should be ok. Your velocity is much higher than mine, but that is due to the different carrier gases. Now I need a little more information. In what way does your chromatogram differ from the one provided? Are you able to identify which amino acids are which? Are your peak heights similar to those provided in the sample? How about your retention times?