WEF Discussion Forums
Laboratory Management and Technical Issues
Matrix spike recovery calculations
Here's a quote from the EPA Inorganics CLP Statement of Work. It's in Section 12.6.7 of Exhibit C:
"When the sample concentration is less than the Method Detection Limit (MDL)...use zero...for purposes of calculating percent recovery."
There may be other references, but this particular one happened to be on my desk.
City of Portland, OR