Chromatography Forum

Hi all,

A question on the compendial method for the analysis of sucralfate. The mobile phase contains about 65 g/L of ammonium sulphate. The stationery phase is amino phase.

What is the purpose of such levels of ammonium sulphate in the mobile phase?

Do you have any suggestions for more robust alternatives for sucralfate related substances separations (in reality, sucrose octasulphate and its heptasulphate impurities)?

Thanks in advance,
Anthony Doyle

In the early 70’s I did some work on the organic chemistry of sucrose.
1. Reactions with sulphuryl chloride under various temp. regimes. Resolved by tlc on silica gel with,
[A] EtOAc: Petr. Ether (1:5 v/v)
or
CHCl3: EtOH (60:1 v/v)

2. Partial de-O-acetylation of Suc (OAc)8
[A] EtOAc: Petr. Ether (1:1 v/v) eluted unchanged starting material, and a second fraction with at least 4/5 components.
CHCl3:MeOH (50:1 v/v) with the second fraction resolved this mixture.

When scouting for a suitable eluent for column chromatography I would develop microscope slides with a very non- polar solvent 4-5 times, with drying in between runs.
Regards,
JMB

My guess is that compound is either retained by hydrogen bonding mechanism or by HILIC with high organic content. Some of the impurities are acidic in nature and you will need high buffer concentration to facilitate elution.