Chromatography Forum

I would appreciate advice for the choice of HPLC column for determination of :

PHENOL
HYDROQUINONE
CATEHOL
ACETIC ACID
FORMIC ACID
MALEIC ACID

Is it possible to analyze all of the analite on the same column and with one run?

Thank you

Dear Karolina,

In a opportunity I had to analyse a pharmaceutic product which has lactic and salicylic acids and I have a lot of problems in order to elute the lactic acid far from the dead time using a C18 column. I think in your problem I try to use an amino or silica column because are polar columns.
Good luck,

Diego

I have had success analyzing organic acids using the Phenomenex Synergi columns, both the Hydro-RP and the Polar-RP. I would also recommend those in addition to others you get here.

You should be able to do all of them in one run if you don't mind a gradient elution. If you want a reversed-phase method, you should use a polar-embedded type column. Resolving acetic and formic acids needs 100% aqueous mobile phase at low pH and moderate ionic strength. The phenolics need a little acetonitrile. You may add the Dionex Acclaim OA column to your candidate list.

This might also be a good application for a mixed-mode anion/RP column.

The phenols are easily done on about any reversed phase column. Any of the columns compatible with 100% water will retain acetic nicely and I expect maleic too. I prefer the ES Industires Aquasep because high surface area makes it very retentive. Use dilute phosphoric acid as the aqueous eluant; 0.02% works just fine. I have no experience with formic. It may separate from acetic with enough retention to be useful. It is worth a try. Use UV detection at 205 nm.

Also these acids may do nicely on a Biorad 87H with dilute sulfuric acid eluant. Don't know about the phenols on this colunmn.

Note, these phenols are easily oxidized by air. If your samples contain very tiny amounts then you may have to take precautions to preclude oxidation.