[ekugrad10]

I am new to the analytical world and am trying to validate an LC/MS. 
I need to test for recovery and know what I need to do, but how to get there is confusing to me.
I need to compare straight extracted calibrators to blank extracted calibrators that have a spike added (straight calibrators). 
My issue is I don't know how much spike to add to the blank extracted calibrators.
I start with 200 uL of calibrator and add 200 ul internal standard.  Sample is extracted in 1.5ml of heptane and reconstitute the sample in 200 ul of 50:50 Methanol to water.  Would I add 20 ul of spike to 180 ul of blank extracted calibrators?

[JGK]

No,

You need to find out the amount of calibrant in the 200 µL and the amount of IS in 200 µL of th IS solution.

You then need to add an equivalent amount to a 200 µL.

However, the experiment you are describing is not a "Recovery" test, it is is more accurately described as a "Matrix Effect" test.

A recovery test would compare extracted calibrators against a set of calibration solutions. Matrix effect measured the effect the marix has on the response of the analyte and IS peaks.

I would suggest that you look at the folowing documenthttp://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm070107.pdf it will give you an insight into some validation practices.