Hello,

I have a question about LOD and recovery during Benzo[a]Pyrene determination in drinking water.
I'm going to calculate LOD according to lowest spike concentration of analyte in water (matrix) free from analyte (ultrapure water).
Average Recovery at this level is 82% (8 replicates) caused by extraction.
In order to calculate LOD I repeat the analysis for 10 replicates at this level and calculated the standard deviation. The LOD is 3.3 * SD.
Is it necessary to correct the values ​​obtained with the average recovery and then calculate the LOD with these new values?

For example:
Spike: 0.0060 ppb
Concentrations obtained without considering average recovery: 0.0048 - 0.0052 - 0.0044 ......
Is it necessary to correct these last values ​​for the average recovery and calculate standard deviation of the obtained results (and then LOD), or can standard deviation be calculated without considering the average recovery?

Thank you all for the help and excuse the bad English.

Greetings,

WK.