Biomass hydrolysates - A challenging sugar separation

[Mark Tracy]

Your situation reminds me of an idea we have been discussing here at Dionex, but no one has actually tried it. Since the CarboPac columns use sodium hydroxide as an eluent, you should be able to put it through one of our Ultra series "Anion Suppressors" to remove the sodium, then detect the sugars by ELSD. We already know that IC/suppression works extremely well as a front end to LC/MS in a variety of applications.

[DR]

^ I'll be looking for that at the next PittCon.^

PS - The column I mentioned has been discontinued, but Varian (Ansys) offers one just like it - "Metacarb"

[Mark Tracy]

Someone here is going to try that. We will keep you posted.

[Chris Pohl]

I'm not sure I understand your problem. You say:

We get satisfactory results HPAEC-PAD but the detector is so sensitive we have to do huge dilutions to get into the linear range of the detector, which introduces its own set of errors.

But it's a simple matter to get dilutions with less than .1% error. All you need is a balance with greater than 1500 g capacity accurate to a milligram. With such a balance you can easily do a 1000:1 dilution with less than 0.1% error. A 1000:1 solution is more than sufficient to take virtually any sample into a useful concentration range in one step for use with HPAE PAD.