Short-chain fatty acids using LC-MS/MS

Hi Zsuzsi,

it all depends on the sizes of the organic acids, your sample preparation, etc.

But take a look at these 2 application notes, it might help:

• 5991-7680EN: https://www.agilent.com/cs/library/applications/5991-7680EN.pdf
• 5991-7980EN: https://www.agilent.com/cs/library/applications/5991-7680EN.pdf

Regards,

Norbert

Hi Zsuzsi,

it all depends on the sizes of the organic acids, your sample preparation, etc.

But take a look at these 2 application notes, it might help:

• 5991-7680EN: https://www.agilent.com/cs/library/applications/5991-7680EN.pdf
• 5991-7980EN: https://www.agilent.com/cs/library/applications/5991-7680EN.pdf

Regards,

Norbert

Thank you, Norbert, 
 
Could you please link the second application note again? The second: 5991-7980EN comes up with a temporarily unavailable message

My primary interests are acetate (C2), propionate (C3), and butyrate (C4). 

I found this paper: https://www.mdpi.com/1420-3049/26/21/6444 
For plasma (50µL), they did protein precipitation with MeOH (100µL) and used a 1290+6490TQ. (Looks almost a bit too good.)
They used a Thermo Hypercarb (Porous Graphitic Carbon, 3 µm (50 mm x 2.1 mm), but I haven't used graphite columns before, and it's hard to judge. 

Phenomenex has similar but different dimensions (Hypercarb 5 µm (100 mm x 4.6 mm)) but recommends a Rezex ion-exclusion column (https://www.phenomenex.com/Application/Detail/5511?returnURL=/Application/Search&fsr=1). It's hard to find any publications that used either of these. 

Thanks for reading, and thank you for your help. Much appreciated.  
All the best, 
Zsuzsi

With pleasure: 5991-7680EN.pdf (agilent.com)

I just checked it and it worked, if not you can always directly at agilent.com put 5991-7980EN in the search field and it should come up.

For the last 30 years we use the HiPLex H type of columns (unloaded ion exchanger) for those small organic acids, sometimes the HiPlex Ca with calcium counter ion. But as always in chromatography, many ways lead to Rome.

Some do ion-pairing with a C18 column, also works.

Regards,

Norbert