Chromatography Forum

Hi,

I am trying to to determine the concentration of vitamin C in some supplement samples. I was wondering if anyone can confirm if running gradient using mobile phase of A( 0.1% acetic acid in water) and B (methanol) with addition of 5 mM of hexane sulfonic acid sodium salt would work?

Thanks.

Hello.
We use an isocratic method at C18 with Tetrabutylammonium hydrogen sulfate as an ion-pairing agent.

I used to use (~40 years ago) an isocratic method using a 250 mm C18 column and a mobile phase of Methanol/cold Metaphosphoric acid for Vitamin C in fish food.

Look at this. Perhaps it helps you.

Trends in Analytical Chemistry, Vol. 27, No. 10, 2008

Have you tried an HILIC method? Give it a shot.

For fish food I used a C18 column and a Mobile Phase (isocratic) of 90% cold metaphosphoric acid in ACN. Wavelength was 248 nm.

That was ~30 years ago (I think)!