The column



LevelBasic

Every column has a limited lifetime.
Good resolution can be completely ruined by a loss in efficiency of a damaged or dirty column, which can be the result of improper handling of the column.

 

Typical GC column problems are:

  • Incorrect installation of the column (dead volume; wrong cut)
  • Incorrect connecton to a splitter
  • Leaking of column couplings
  • Incorrect use of the column
    • wrong polarity
    • wrong temp settings
    • Incorrect oven temperature Wrong storage of the column
  • Overloading by mass or volume
  • Contamination of the column
  • Incorrect carrier gas velocity 
  • Breakage 
  • Ageing (oxidation, pollution, bleeding)

The plate number and the plate height are used by manufacturers in test reports to express the efficiency and quality of the columns. It is recommended to determine the plate number after installing a new column:

  • To verify whether the column has in actual fact that quality
  • To check whether the entire chromatographic system has the high quality we expect

A manufacturer performs column tests under optimum conditions: correct installation of the column, optimum gas velocity, minimal external causes for efficiency loss etc. If, however, the user finds plate numbers that differ substantially form these values for one or more columns, this is an indication that something is wrong with the system.

 

A periodical test (e.g. once a month) can provide information about the decline of quality of the column in particular.                    -

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