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- Posts: 3210
- Joined: Thu Sep 02, 2004 7:28 pm
Yes, you are quite right, a new column may be the solution.
Any column based on a silicone phase if it receives oxygen from a leak in a regulator or in any of the pneumatic control devices found in modern GCs will have active sites of an acidic nature.
In general, a thicker film will protect the surface active sites better than a thin film will.
Given that you have a fairly polar analyte to measure a phase more polar than a 5% phenyl (that means there are a lot of them) might be a better solution for you. A VOCOL, a 624, a 1701, a deactivated for bases PEG are all possibilities and I suspect any of them would do well.
Glass wool is not needed for almost all applications, and it adds endless opportunities for active sites in an injector as the glass is heated to high temperatures and is exposed to high concentrations of solvents and air-water from the act of injecting samples.
If so some reason you have to have additional surface area, try using quartz wool instead of glass, or slow the injection speed so that the solution of analytes has less opportunity to not fully vaporize in the injector.
Worst case, get a megabore column and inject on-column (do a little reading and educate yourself).
It may take time but you will learn from experience, and that sometimes is the better way of solving problems and understanding the issues involved, but it isn't the least painful.
I wish you success in your endeavors.
Rod
Any column based on a silicone phase if it receives oxygen from a leak in a regulator or in any of the pneumatic control devices found in modern GCs will have active sites of an acidic nature.
In general, a thicker film will protect the surface active sites better than a thin film will.
Given that you have a fairly polar analyte to measure a phase more polar than a 5% phenyl (that means there are a lot of them) might be a better solution for you. A VOCOL, a 624, a 1701, a deactivated for bases PEG are all possibilities and I suspect any of them would do well.
Glass wool is not needed for almost all applications, and it adds endless opportunities for active sites in an injector as the glass is heated to high temperatures and is exposed to high concentrations of solvents and air-water from the act of injecting samples.
If so some reason you have to have additional surface area, try using quartz wool instead of glass, or slow the injection speed so that the solution of analytes has less opportunity to not fully vaporize in the injector.
Worst case, get a megabore column and inject on-column (do a little reading and educate yourself).
It may take time but you will learn from experience, and that sometimes is the better way of solving problems and understanding the issues involved, but it isn't the least painful.
I wish you success in your endeavors.
Rod
