Ascorbic acid

Basic questions from students; resources for projects and reports.

3 posts Page 1 of 1
Hi! I am trying to analyze ascorbic acid with HPLC. I am using a HILIC amide column 2.1 i.d. My mobile phase is acetonitrile/buffer 60/40 (10mm ammonium formate/0.15% formic acid). 0.25 ml/min. The peak elutes after 4.2 minutes. When I am analyzing soft drinks the peak areas are wery similar but when I am preparing standards the areas change very much when I am injecting from the same vial. I have tried to use some stabilizing agents such as oxalic acid an phosphoric acid. I have also changed the mobile phase composition so it contains more acetonitrile. Does anyone have an idea about what is happening? I have also tried C18 column but I could not retain AA on that one.
As I recall, when I was analysing Ascorbic Acid you have to use meta-phosphoric acid (not ortho!) in your extraction buffer and mobile phase in order to prevent the formation of the dehydro form. The final pH should be acidic.
I also used Methanol instead on Acetonitrile.
3 posts Page 1 of 1

Who is online

In total there are 7 users online :: 0 registered, 0 hidden and 7 guests (based on users active over the past 5 minutes)
Most users ever online was 599 on Tue Sep 18, 2018 9:27 am

Users browsing this forum: No registered users and 7 guests

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry