removal of ionic contaminant for carbohydrate analyis

[pvolny]

Hello all,

I am trying to measure sucrose, glucose, fructose in fermentation sample. I have a Supelco Ca column and need to remove ions from the sample as they will be detrimental to the column. As per the manufacturers instructions I am mixing 10 part volume to 1 part weight of mixed bed resin.

My question is can the time,mixing level and/or precise quantity of mixed bed resin used for this sample prep step affect the concentration of analyte in the sample?

I am running standards and am getting some inconsistency between samples. I did a test where I made a standard of 1g/L glucose, ran it on the HPLC and then did the treatment with mixed bed resin on the same exact standard solution and got a lower peak area for sample treated with resin. Could my sample prep step be affecting analyte concentration?

The mixed bed resin I am using is TMD-8 hydrogen and hydroxide. Method is 85°C, 0.5mL/min 20uL injection volume, H20 mobile phase.

What is your procedure for removing ionic contaminant for carbohydrate analysis column sample prep?

Thanks much for any advice.

[Markus Laeubli, Metrohm]

I assume that a wet ion exchanger resin might give some dilution effect.

[pvolny]

I assume that a wet ion exchanger resin might give some dilution effect.

Thanks for the response, I did not think of that but it does make sense as the resin does look a bit moist. As the resin is used at a 1:10 weight/volume ratio I think that at the very most there could be a 10% increase in volume, I will check to see if this is enough to explain the variation I am seeing between non-resin treated and resin treated sample.