Stationary phase used should ideally be matched to the phase in the analytical column, both in particle size and also in bonded stationary phase.
- Connections should be made with a low or nil volume connector such as the direct connect shown above.
- The length of the guard should have no discernable effect on the chromatography achieved. Generally a 10mm guard column will be suitable to protect the analytical column from all but the most contaminated samples.
- The i.d. of the guard should be kept as close as possible to the i.d. of the analytical column in order to prevent pressure problems.
- It must be remembered that the guard is there to provide protection of the important analytical column, therefore the guard cartridge should be replaced on a much more frequent basis than the analytical column.
The lifetime will depend heavily on many factors, such as the quality of the solvents, the sample matrix and the expected number of sample runs. Guard columns should be changed when changes in backpressure or column efficiency are observed.
HPLC Filter
The HPLC filter is for use if you do not want to use a guard system or as well as a guard system, it has a 2um frit to protect the analytical column from particulate matter:
- Low Volume, No backpressure increase
- Increase lifetime of UHPLC columns
- Change over time seconds not minutes
UHPLC Filter
UHPLC filters should be used to protect any UHPLC column in use. Combining the 0.5um filter at the front of the column will help to prevent blockage from particulate matter.
- Low Volume, No backpressure increase
- Increase lifetime of UHPLC columns
- Change over time seconds not minutes