I have had some trouble with leaking when using a Chromolith guard column with a Chromolith analytical column. These are built with "fiber" cases, with which I must admit I had no prior experience. The 'guard column' consists of three pieces - the column (aka cartridge) itself, and two parts of housing in which the guard column sits. The end user sets this up by placing the guard column/cartridge into one part of the housing, and screwing on the other half of the housing. The instructions are quite insistent on fingertightening, and not over-tightening this coupling.
When trying to install the guard column I kept getting a leak at the point where the two housing parts screw in together. It seemed like if I was too careful about over-tightening, then it leaked because it wasn't tight enough. And if I tightened it to stop leaking (finger-tight only), then it probably deformed the fiber casing causing either a leak or excess pressure. At low pressures, I could find a narrow sweet spot where there was no leaking, but as soon as the pressure went up (well within the operating pressure limits of the column), it would leak again.
I had this problem with multiple guard column kits (incidentally from the same lot #). EMD Millipore support was very prompt with responding to my request for help, and I finally got a guard column that works fine.
I am wondering if this was a case of a bad lot, or if the fiber case is finicky and prone to such problems. Does anyone have experience with these guard columns? Has anyone faced similar issues?
Seems like there are not many people here using these particular columns.
Here are my observations from recent experience:
The guard column cartridge must fit snugly into the cartridge holder. If it does not fit snugly, it will leak. The only option (if it does not fit snugly and leaks) appears to be to use a different cartridge.
The guard column should not be tightened too much (even with just fingers) when attaching to the analytical column. This seems to pinch the guard column outlet causing a huge pressure buildup. The difference between too loose (leaking) and too tight (excess pressure) seems to be just a little over a quarter turn.
Hopefully this will help someone!
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