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- Posts: 1
- Joined: Thu Jul 22, 2010 8:39 pm
Bio-Rad Animex HPX-87H column
Waters SH-G guard column
Waters W2996 PDA detector
Hi everyone,
I am new to this forum and I hope my question is not too basic. I am looking to improve my current method for short chain fatty acid analysis in particular the sample preparation. My company has been using the same method for over 6 years, but I am not convinced it is working. The matrix is liquid manure and sometimes solid fecal material.
Problems:
I suspect poor recovery from samples
Last component RT is 60 min
Major tailing in standards after 45 min
Large, 5-8min gaps between peaks
Current method:
isocratic with 5mM H2SO4 mobile phase
35 C column temp
0.6 ml/min flow rate
PDA wavelength 224
10g sample centrifuged at 5000 rpm for 5 minutes
1 ml of supernatant is diluted in 9 ml mobile phase, vortexed, and filtered through a 0.2 um filter
Proposed new method:
isocratic with 10% acetonitrile in 5mM H2SO4
65 C column temp
0.6 ml/min
PDA wavelength 210
sample prep ?
Unfortunately I am not a chemist and since no one knows how to use the HPLC at my work, I am on my own. I've found literature for fecal sample prep for GC, but not HPLC. Any help would be appreciated!