sudden drop in baseline
Posted: Fri Sep 22, 2006 5:03 pm
I would like to follow up on a question I posted more than a year ago, see the link to the old post which contains chromatograms: http://www.sepsci.com/chromforum/viewtopic.php?t=1591
When we encountered this issue, we were under very tight timeline to get the method done. So we switched the column from Synergi Polar-RP to ODS AQ. The baseline issue was resolved even though sample diluent, mobile phases and gradient remained the same. We never had time to go back and figure out what was going on.
A few months ago I was developing a new impurity method for a new compound. During the column screening stage, I saw the same baseline issue again with the Synergi Polar-RP but not with other Synergi columns. The problem was more pronounced at low wavelengths (210 or 220 nm), but not observed at 250 nm. I called the column vendor and was told that such baseline was known as the “shark fin baselineâ€
When we encountered this issue, we were under very tight timeline to get the method done. So we switched the column from Synergi Polar-RP to ODS AQ. The baseline issue was resolved even though sample diluent, mobile phases and gradient remained the same. We never had time to go back and figure out what was going on.
A few months ago I was developing a new impurity method for a new compound. During the column screening stage, I saw the same baseline issue again with the Synergi Polar-RP but not with other Synergi columns. The problem was more pronounced at low wavelengths (210 or 220 nm), but not observed at 250 nm. I called the column vendor and was told that such baseline was known as the “shark fin baselineâ€
