2011-02-15 (Tue) 07:16:49 Shodex Technical question

Record: 156

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Category: Specifications Product: SP0810, NH2P50 Sample: saccharides

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Question We use HPLC columns SP0810 and NH2P-50 4E to analyze sugars. My question is: is it OK to inject 5uL samples containing ~0.5M sulfuric acid directly onto those two columns? if not, can we just neutralize the sample with equimolar sodium hydroxide and then make the injection? Currently we’re neutralizing the sample with excessive calcium carbonate but this process causes some probelm such as potential sugar loss to the precipitates.     Answer 1, SP0810 We do not recommend to inject the sample solution through the columns without removing acids and cations. The packing material of SP0810 has sulfo group as the functional group, and lead ion(Pb++) is used as its counter ion. This counter ion is removed by the acids. That is, the form of the functional group is changed from Pb++ to H+. And it is the same for the other cations. Pb++ is exchanged to the others, when the sample solution is containing a lot of cations like Na+ or Ca++. When the counter ion of the functional group is exchanged, the separation performance of the column is changed. And it is difficult to regenerate the counter ion, once the counter ion is exchanged to the others. So, we recommend to remove the ions in the sample solution before the analysis to protect the functional group. 2, NH2P-50 4E The separation performance of this column s not interfered by cations. However, anions interfere the separation performance as the following page. http://www.shodex.com/english/dc030234.html Acid ion in the sample solution will combine the amino functional group, and the functional group of NH2P-50 becomes the acid type. That means the separation performance is changed. Although it is possible to regenerate the amino functional group, we recommend to remove acids before the analysis for the repeatability of the analysis. So, we think the sample pretreat method you are using is the best to remove sulfuric acid. This is for your information. If Shodex SH1011 column can separate the targets, SH1011 is better for use, because the eluent condition is sulfuric acid aqueous solution and it does not need to remove sulfuric acid from the sample. We will attach one URL just for the example. http://www.shodex.com/english/dc030508.html And if SH1011 cannot separate the targets, DC-613 may be usable, because it is possible to injection the sample solution with just neutralizing by NaOH. Please refer to the attached file. (See attached file: 110210 DC-613.pdf)     Additional Comments