Small organic acids, lc/ms/ms, separation and detection limi
Posted: Tue Sep 25, 2007 12:04 pm
I’m currently trying to analyse small organic acids. I know it has been discussed quite a bit already. However I haven’t been able to solve my problems by looking in this forum or searching the literature. I was thinking maybe some of you guys could help?
A brief introduction:
I would like to analyse (detect and quantify) 7 of the acids in the citric acid cycle (krebs cycle/tricarboxylic acid cycle)
So far I have been able to separate them quite well including citric acid and isocitric acid. In order to separate the last two, I used water (0.1% formic acid). Monitoring in negative ion mode I don’t obtain high sensitivity though. I believe this is a question of pH. However adjusting to a less acidic or neutral pH I’m unable to separate the citric acid and the isocitric acid.
For your information I’m using the following lc/ms/ms system:
‘Waters 2695’ separation module with a ‘Waters micromass Quatromicro™ API ‘ mass spectrometry system.
Regarding the problem (challenge?) with sensitivity:
In the following article “J. Agric. Food Chem, 2007, 55, 551-560â€
A brief introduction:
I would like to analyse (detect and quantify) 7 of the acids in the citric acid cycle (krebs cycle/tricarboxylic acid cycle)
So far I have been able to separate them quite well including citric acid and isocitric acid. In order to separate the last two, I used water (0.1% formic acid). Monitoring in negative ion mode I don’t obtain high sensitivity though. I believe this is a question of pH. However adjusting to a less acidic or neutral pH I’m unable to separate the citric acid and the isocitric acid.
For your information I’m using the following lc/ms/ms system:
‘Waters 2695’ separation module with a ‘Waters micromass Quatromicro™ API ‘ mass spectrometry system.
Regarding the problem (challenge?) with sensitivity:
In the following article “J. Agric. Food Chem, 2007, 55, 551-560â€