recoveries more than 100% [Bioanalytics]
Dear Deepak,
» The % recovery was determined by comparing the mean peak area of 6 replicates of extracted quality control samples at High, Middle and Low concentrations against respective mean peak area of 6 replicates of un-extracted quality control samples at High, Middle and Low concentrations.
Meaning that what you observe is a mix of extraction recovery and matrix effect. If you want to see the true extraction recovery you have to compare to samples spiked post-extraction. You can combine with matrix effects experiments.
» Internal standard used was deuterated.
Makes no difference. You are looking at peak areas, not peak area ratios.
» Kindly confirm recoveries markedly higher than 100% for LQC, MQC2 and MQC1 are acceptable as per USFDA guidelines??
Did you see any limit for absolute recovery in either direction in the FDA guidance ?
» Also specify reason for higher recoveries.
Multiple. The most probable: analytical variability (your results are well within the 15 % acceptance limits for precision and accuracy). Other possibilities include ion enhancement, sample preparation, calculation errors...
» The % recovery was determined by comparing the mean peak area of 6 replicates of extracted quality control samples at High, Middle and Low concentrations against respective mean peak area of 6 replicates of un-extracted quality control samples at High, Middle and Low concentrations.
Meaning that what you observe is a mix of extraction recovery and matrix effect. If you want to see the true extraction recovery you have to compare to samples spiked post-extraction. You can combine with matrix effects experiments.
» Internal standard used was deuterated.
Makes no difference. You are looking at peak areas, not peak area ratios.
» Kindly confirm recoveries markedly higher than 100% for LQC, MQC2 and MQC1 are acceptable as per USFDA guidelines??
Did you see any limit for absolute recovery in either direction in the FDA guidance ?
» Also specify reason for higher recoveries.
Multiple. The most probable: analytical variability (your results are well within the 15 % acceptance limits for precision and accuracy). Other possibilities include ion enhancement, sample preparation, calculation errors...
—
Regards
Ohlbe
Regards
Ohlbe
Complete thread:
- recoveries more than 100% deepakpangavhane 2018-09-03 08:28 [Bioanalytics]
- recoveries more than 100%Ohlbe 2018-09-03 19:21
- recoveries more than 100% Ladi 2018-09-04 03:51
- recoveries more than 100% Kintan Patel 2018-11-29 11:48
- Origin of figures ? Ohlbe 2018-11-30 18:23
- Origin of figures ? Kintan Patel 2018-12-05 10:04
- Origin of figures ? Ohlbe 2018-12-05 10:30
- Origin of figures ? Kintan Patel 2018-12-05 10:04
- Origin of figures ? Ohlbe 2018-11-30 18:23
- recoveries more than 100% Kintan Patel 2018-11-29 11:48