Those of you who work in analytical laboratories and work extracting analytes from soil samples:

Many procedures involve spiking a soil sample first with various standards, shaking the soil sample, THEN adding a solvent like methanol or acetone to break up the sample matrix and remove moisture. My question is, does it make any difference whether or not you spike first or add the acetone/methanol first? Does either one result in better recoveries? Why? I know one other procedure for PCB/PAH compounds has the soil samples sitting in methanol already, after which it is simply spiked and then shaken to break up the soil. The procedure I'm particularly curious about is used to extract BNA from soil, but these samples are not kept in methanol unlike the PAH/PCB extraction. Why is this?

Really curious about this because everyone in the lab was arguing over whether or not it matters with all kinds of ideas being thrown around.