Extraction Recovery of Analyte(s) and Internal Standards

  • Recovery of the analyte(s) is calculated using the in-range quality control samples at three different concentration levels. The study compares the responses of the analyte(s) and IS from the validation QCs to the responses in non-extracted samples prepared in mobile phase/reconstitution solvent.
  • The percent recovery of the analyte is calculated at each concentration level by dividing the mean response of the analyte (minimum of three determinations) in the matrix sample by the mean response of the analyte at that concentration in the non-extracted samples.
  • The percent recovery of the internal standard is calculated by dividing the overall mean response of the internal standard in the matrix samples by the overall mean response of the internal standard in the non-extracted samples.
  • Recovery studies for stable-labeled internal standards are not required, since, by definition, it is chemically like the analyte.