Log in
RegisterRecovery vs. overall efficiency [Bioanalytics]
Dear Rajasekhar,
OK. Then I would not call this recovery but rather overall efficiency. What you have measured is a combination of the yield of your extraction or protein precipitation method (which is what I would call recovery) and matrix effects.
If you want to evaluate the recovery of your extraction method when using LC/MS methods you should compare the response of extracted samples to the response of blank samples, extracted and then spiked post-extraction. That's an experiment you can combine with matrix effects, where you will compare the response in samples spiked post-extraction to the response in aqueous samples:
- recovery: response in extracted samples / response in samples spiked post extraction
- matrix factor: response in samples spiked post extraction / response in aqueous samples
- overall efficiency: response in extracted samples / response in aqueous samples
The low "recovery" (below 40 %) you had for analyte B with your protein precipitation method is probably due to matrix effects. As mentioned by Helmut protein precipitation is the worst sample preparation method you may think of when using LC/MS methods. Fast, cheap, easy, but terrible.
Regards
Ohlbe
❝ The percent recovery was evaluated by comparing the peak area of extracted
❝ samples and peak area of un-extracted (Aqueous) samples.
OK. Then I would not call this recovery but rather overall efficiency. What you have measured is a combination of the yield of your extraction or protein precipitation method (which is what I would call recovery) and matrix effects.
If you want to evaluate the recovery of your extraction method when using LC/MS methods you should compare the response of extracted samples to the response of blank samples, extracted and then spiked post-extraction. That's an experiment you can combine with matrix effects, where you will compare the response in samples spiked post-extraction to the response in aqueous samples:
- recovery: response in extracted samples / response in samples spiked post extraction
- matrix factor: response in samples spiked post extraction / response in aqueous samples
- overall efficiency: response in extracted samples / response in aqueous samples
The low "recovery" (below 40 %) you had for analyte B with your protein precipitation method is probably due to matrix effects. As mentioned by Helmut protein precipitation is the worst sample preparation method you may think of when using LC/MS methods. Fast, cheap, easy, but terrible.
Regards
Ohlbe
Complete thread:
- IS (polarity switching mode) drajasekhar 2009-12-27 10:43
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- IS (polarity switching mode) Ohlbe 2009-12-28 01:00
- LC-MS/MS method in the ionization Switching modes drajasekhar 2009-12-28 06:32
- Recovery? Ohlbe 2009-12-30 13:51
- Recovery? drajasekhar 2009-12-30 14:45
- Recovery vs. overall efficiencyOhlbe 2009-12-30 17:36
- Recovery vs. overall efficiency drajasekhar 2009-12-30 18:17
- Recovery vs. overall efficiency Ohlbe 2009-12-30 19:16
- Recovery vs. overall efficiency drajasekhar 2009-12-30 19:50
- Recovery vs. overall efficiency Helmut 2009-12-30 19:58
- Recovery vs. overall efficiency drajasekhar 2009-12-30 20:35
- Recovery vs. overall efficiency Helmut 2009-12-30 20:38
- Recovery vs. overall efficiency Ohlbe 2009-12-30 20:43
- Recovery vs. overall efficiency drajasekhar 2009-12-30 20:54
- Recovery vs. overall efficiency drajasekhar 2009-12-30 20:35
- Recovery vs. overall efficiency drajasekhar 2009-12-30 18:17
- Recovery vs. overall efficiencyOhlbe 2009-12-30 17:36
- Recovery? drajasekhar 2009-12-30 14:45
- Recovery? Ohlbe 2009-12-30 13:51
- Matrix Effect drajasekhar 2009-12-28 07:00
- Matrix Effect Helmut 2009-12-28 14:18
- Matrix Effect Ohlbe 2009-12-30 13:53
- LC-MS/MS method in the ionization Switching modes drajasekhar 2009-12-28 06:32
- IS (polarity switching mode) Ohlbe 2009-12-28 01:00
Ing. Helmut Schütz