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- Posts: 310
- Joined: Mon Aug 30, 2004 4:56 pm
WK,
There is no reason for PEEK to present problems at low pH with a cationic solute. In fact, if there was any effect at all it should be the opposite since all extruded tubing has traces of carboxylate groups on the surface which could potentially effect peak shape at high pH. This should only be true at high pH where the carboxylate sites are ionized and even then there isn't likely to be any effect unless the eluent and sample contain no electrolytes. Most likely as suggested by Uwe, there are "plumbing" issues with the system with the PEEK tubing which explains the peak shape problem.
There is no reason for PEEK to present problems at low pH with a cationic solute. In fact, if there was any effect at all it should be the opposite since all extruded tubing has traces of carboxylate groups on the surface which could potentially effect peak shape at high pH. This should only be true at high pH where the carboxylate sites are ionized and even then there isn't likely to be any effect unless the eluent and sample contain no electrolytes. Most likely as suggested by Uwe, there are "plumbing" issues with the system with the PEEK tubing which explains the peak shape problem.
