Chromatography Forum

Hi all I have a quick question:

What is the max pressure I can run on a 5890?

I am adapting/developing a method for amino acids analysis via ethyl chloroformate derivitization. The original method uses a 10m .25 .25 1701 column. I am unhappy with the resolution between glutamate (our prime analyte MSG) and phenylalanine and I am also planing to switch to H2 from He in the near future so I am looking at .18 columns. There is a 20m .18 .18 column (the only 10m has .43 phase thickness) available. According to method translater I would be running at maximum 34psi for direct tranlation or 26 psi for maximum efficiency. The orginal method uses rather high linear velocities to save time 53-73 cm/sec

i think 100 psi, 30-40 psi should work fine.

Agilent has 2 EPC modules. One with a max pressure of 100psi, the other is 150.

Wow I never thought of running a GC at 100 psi. Agilent doesn't even recommend supplying gases to the inlet from the regulator at 100 psi (I set it at 80). However chemstation allows me to enter it. I never go much past 25 on my 6890.

MSChemist,

There are some packed column applications that use very high head pressures. In addition, very narrow id capillary columns require much higher head pressures.

Best regards,

AICMM