2011-05-24 (Tue) 00:30:20 Shodex Technical question

Record: 267

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Category: Column Selection Product: SUGAR Sample:

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Question F6378100 (SUGAR SH1011). Is this column 4% crosslinked version that should resolve between sugars with DP up to about 6.     Answer 1) Are these poor images or would I expect not to be able to integrate data for oligos over DP3-4? Although DP6 is not included for this data, please refer to the following page regarding the separation performance of SH columns for DP3-4. http://www.shodex.com/english/dc030266.html 2) Would two columns in series (same or one of each) work to benefit the resolution of the larger sugars as I would expect? The separation performance between DP3 and DP4 is improved with using two columns. However, we think it is impossible to separate the oligosaccharides larger than DP5 at the base line. 3) Would an acidic sugar (carboxylate modification) be expected to elute earlier or later then an identically size nuetral sugar? It depends on the eluent condition. If the eluent condition is just H2O, acidic sugars will be eluetd earlier than neutral sugars by ionic repulsion . And if the sample solution is also including the oligosaccharide which is eluted near from the exclusion limit, the peaks of acidic sugars and oligosaccharides will be over rapped. Additionally, this ionic repulsion depends on the acidic degree of the compounds. We confirmed that SH1011 cannot separate glucose and gluconic acid with H2O as the eluent condition. In the case of that the acidic degree of the compound is not strong, this repulsion does not work. If the eluent condition is acidic aqueous solution, acidic sugars are separated by size and ionic repulsion, because the functional group of the compounds and the stationary phase are suppressed by the eluent. 4) What is the interaction of carboxylic acids with the stationary phase? Ionic repulsion works between the stationary phase and the carboxylic group.     Additional Comments