Query on Plate counts for HPLC SST


Can anyone explain wht criteria should be used to set the minimum plate count for HPLC system Suitability. CDER recommends 2000.

I have a situation where during method validation for a multi analyte method, the first component had a plate count of 3000, when the column was new. I set a minimum plate count of 2000. Now I have a situation where the plate count is below 2000 ie 1800.

Is there any guideline eg. if the initial plate count was 3000, then SS plate count can be half (1500)


Decrease in plate count , may be from two fold reasons.

  1. Nature of analyte and its load (for ex in case of High mol.wt compound with Referactive detector)
    If similar situations has arised with same analyte of different lot of column[of same make], you can rule out, Decrease in plate count is due to analyte itself.
  2. Stability of packing.
    If No decrease is observed after injecting same analyte with different lot of column[of same make], you can rule out, Decrease in plate count is due to particular lot of packing.

As such there is no guideline, that final plate count shall be half to the initial.

It also indicates, by the end of analysis, the separation efficiency of your column is not similar to its intial separation.

Try to work out for an alternative method.

there is a reference, as such,

capacity factor, k’ > 1.5
tailing < 2 / 1.5
plate count (USP) > 1500
resolution > 1.5

try look into USP or BP, general chapters on chromatography

It is obious to decrease in plate count as column become older. Since ur column passes SST (Resolution,capacity factor, taliling factor)and ur inhouse specificatin doesn’t talk about plate count, in such case inhouse specification supershades USP,BP requirment

We can use analytical column in the preparative HPLC (for amino acid Analysis) for amino acid analysis

I am new bie for this valuable issue

Kindl provide the easy method to analysis by HPLC

Thanking you