tag:blogger.com,1999:blog-1881251140360229837.post2371679178945587137..comments2023-07-11T21:16:12.345+01:00Comments on Mourne Training Services: Help on: Retention time shift in HPLC analysisUnknownnoreply@blogger.comBlogger2125tag:blogger.com,1999:blog-1881251140360229837.post-42156444347805834672013-03-15T10:13:34.636+00:002013-03-15T10:13:34.636+00:00A delay of 60% is quite large, I think that the mo...A delay of 60% is quite large, I think that the most likely cause is related to an increase in the organic content of the mobile phase composition. Although you believe that there has been no change to the conditions, I would check this thoroughly.<br /><br />It is unlikely that the change would be due to the pump if the flow rate and pressure are satisfactory but it could be due to a problem with the mobile phase mixer.Oona McPolinhttps://www.blogger.com/profile/11016193415167924469noreply@blogger.comtag:blogger.com,1999:blog-1881251140360229837.post-2686061285528267462013-03-14T18:23:27.548+00:002013-03-14T18:23:27.548+00:00I'm having this problem, since about a month a...I'm having this problem, since about a month ago, and all peaks are very consistently delayed ~60%, with no apparent change to the method, solvents, columns, compounds, etc.<br /><br />I've changed columns to no effect. I assume that this has something to do with the pumps, but the pressure is constant and at the same level as before the shift, as well as the external flow rate. I'm not quite sure where to go from here, but I'll try to flush any air from the lines which may be causing the delay.Anonymousnoreply@blogger.com