In line filter/pre column

[Provetech]

I wonder if an inline filter (ex. 2µm) is useful if i alredy use a precolumn in order to avoid inlet frit plugging....and backpressure increase.
Please give me an advise.
Thanks

[HW Mueller]

You want to guard the guard? Next question: Should one guard the guard with a guard?
Well, seriously, an inline filter (frit, sieve) between the pump and the injection valve is not a bad idea, especially if your injection valve is connected with 0.1mm capillaries.

[Mark Tracy]

I used to have a couple customers (a previous job) who never filtered their samples before analysis. They just changed the 0.5 micron pre-column filter once a day. They never complained about column life, but sure did if we couldn't ship frits on time!

[Jeff Brewer]

I have always taken the position it is better to protect my column than justify a replacement. A small guard disc is much less expensive than a guard column or column. There are several on the market which have proven to perform well without sacrificing the separation. I have successfully used inline filters from Upchurch, RP or Universal Disc technology from Transgenomic and the Metrohm RP Universal Guard Disc. Phenomenex and Alltech also have simliar products I just have not used them personally. These are inexpensive and they do protect your column investment.