Ultrasensitive and automated 1 pg/ml fluticasone propionate assay in human plasma using LC-MS/MS.

Background: To develop and validate an ultrasensitive bioanalytical assay for quantitation of fluticasone propionate in human plasma, aliquots of 0.6 ml of K(3)EDTA human plasma were treated with zinc sulfate solution and loaded onto a preconditioned SPE plate. The sample solutions were washed, eluted, dried and reconstituted.