2012-02-22 (Wed) 06:33:53 Shodex Technical question

Record: 542

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Category: Specifications Product: KF Sample:

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Question What is the typical service life of this column? We’ve been operating it fairly regularly since the end of October 2011 and we are getting a peak at around 15 minutes in all of our samples and we’re trying to determine if we have a contaminant in our DMF or if the column has reached the end of its service life.     Answer We do not set the column life for Shodex columns, because the column life is interfered by the sample condition, the frequency of the analysis and so on. Is the flow rate 1.0mL/min? If so, the peak at 15min may come from water or air in the sample solution. Please refer to the following application data for example. Both of the data have the minus peaks around 25min with using two columns. These peaks come from the air in the sample solution. http://www.shodex.com/english/dc060701.html http://www.shodex.com/english/dc060702.html And if the eluent condition is containing LiBr, there is the case that the peak of LiBr is also appeared at lower molecular weight range. So, we think the column is not deteriorated even certain unknown peak is appeared at 15mL of elution volume. Or, if there is any doubt for the chromatograms, we would like to see them, if it is possible. In this case, could you please send them by e-mail? This is for your information. We do not guarantee the column performance of KF-801, if the column is used DMF. Please refer to the following page regarding the availability of the organic solutions for KF-800 series columns. http://www.shodex.com/english/da060309.html If the KF-801 is used normally with DMF, we recommend not to exchange the eluent condition any more.     Additional Comments