Bioequivalence and Bioavailability Forum

Dear Charl,

In Recovery experiment, we spike the blank biological matrix (example: plasma) and process (extraction) the sample for analysis. Now we compare the instrument response for the analyte in this 'spiked and extracted' sample with the instrument response for the analyte in the mobile phase. This gives us the recovery data.

In matrix effect, we first process (extract) the blank biological matrix (plasma) and spike it with analyte after extraction. Now we compare the instrument response for the analyte in this 'extracted and spiked' sample with the instrument response to the analyte in the mobile phase. This gives us the matrix factor, when we use the discussed calculation.

Hence, matrix effect in LC-MS/MS are determined independent of recovery experiment. By doing so, we are taking care that the matrix factor determination (by spiking after extraction) is not influenced by the recovery (spiking before extraction).

For all the LC-MS/MS methods, matrix factor needs to be determined irrespective of whether the method involves Protein precipitation or Liquid-liquid extraction or solid phase extraction.

With best regards,
V.Pardhasaradhi