Chromatography Forum

Hello everybody,
I have to analyze some new formulations containing Xanthan Gum. Since it clogs the column I did a clean up with SPE C18. This works fine for the assay of my drug since it is apolar, it doesn’t with the impurities. This because some of them are mid-polar. They are retained in the SPE column when xanthan gum is not present, otherwise a 10% of them pass in the aqueous fraction. This problem can be avoided with multiple loadings of the aqueous fraction in SPE column. Of course the method becomes very long.
So this is the question, how I can remove xanthan gum from the matrix of my sample? I thought 2 things: preparative GPC or CN SPE column. Any suggestion?
Thank you

Gums (camides )such as polysaccharides, any polysaccharides insoluble. in 96% ethanol ,acetonitrile and THF

Luke did you ever find a good solution to your problem? kind of facing same problem for my project. thanks in advance!!!

Gums are extremely detrimental to an HPLC system and analytical column. I almost lost a column after only 1 month of injection before realizing it was a big problem. Only filtrating your sample with a 0.45 syringe filter will not resolve the issue.

As mentioned before, xantham gum is insoluble in many organic solvents and it will precipitate when mixing it with methanol, for example. The only important solvent for it is water. You can dilute your sample using methanol or a mixture of methanol:water to precipitate the gum, and then either filtrate or centrifuge the diluted samples before injection.

There is an interesting discussion in the following paper: "Quantitative HPLC Analysis of Active Pharmaceutical Ingredients in Syrup Vehicle Using Centrifugal
Filter Devices and Determination of Xanthan Gum in Syrup Vehicle Using Rheometry" - by Yong Chen, Tanya Tadey, Mougang Hu, Geoff Carr, and Junan Guo. The authors used viscosity results to see if they eliminated xantham gum from solution.

I'm not sure how I would proceed if the analyte also had problems with organic solvents. It is important to see if you get good recoveries with what you chose to work.

I was working with analyzing a sugar free jello for acesulfame K and aspartame. I tried Carrez clarification with 20%CH3CN and could not filter it. What worked for me was extracting it with 80% ethanol, take 1ml and evaporate with nitrogen, redissolve in 1ml of 10% CH3CN. If I injected the 80% ethanol it would have defocused especially the Acesulfame K which elutes at 10% CH3CN.

I was able to analyze the jello by adding 2ml of water then within seconds before it could start to gel up add ethanol to the 10ml mark, give it a spin in the centrifuge. I then blew it down with nitrogen/moderate heat and redissolved in aqueous mobile phase and filter.