Bioequivalence and Bioavailability Forum

Hey guys.

Glad to found this forum! I have a seemingly silly question. We are discussing after yrs of the practice which order in spiking blank plasma is the best.

My way - spiking of the matrix: into the eppendorf tube is pipetted a volume of blank matrix, then is spiked by solution with analyte.
(This is imho better and safer approach, we need not worry about sorptions or evaporation of the solvent)

Way of my older colleague - spiking of empty tube: into the eppendorf tube is pipetted a volume of solution with analyte, then a volume of blank matrix.
(I guess this approach has a flaws mentioned above, and it's just seems to me illogical. It could be useful if the solvent has a high content of an organic matter to ensure an immediate homogenization without precipitation, but no one of us is developing methods like that if possible, right?)

I'll be glad if there will appear some clear answer.
Thanks in advance.