title: Simultaneous assay of sildenafil and desmethylsildenafil in human plasma using liquid chromatography-tandem mass spectrometry on silica column with aqueous-organic mobile phase.
abstract: A liquid chromatography-tandem mass spectrometry method was developed for the analysis of sildenafil (SIL) and its metabolite desmethylsildenafil (DMS) in human plasma. Samples were accurately transferred to 96-well plates using a liquid handler (Multiprobe II). Solid-phase extraction was carried out on a 96-channel programmable liquid handling workstation (Quadra 96) using a C8 and cation-exchange mixed-mode sorbent. The extract was injected onto a silica column with an aqueous-organic mobile phase, a combination that was novel for improving the method sensitivity. The low limit of quantitation was 1.0 ng/ml for both SIL and DMS. The method was validated to meet the criteria of current industrial guidance for quantitative bioanalytical methods.
authors.affiliation: Covance Laboratories Inc., Madison, WI 53704, USA.
authors.forename: Angela
authors.initials: A
authors.lastname: Eerkes
authors.forename: Tom
authors.initials: T
authors.lastname: Addison
authors.forename: Weng
authors.initials: W
authors.lastname: Naidong
mesh_terms: D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D010879:Piperazines / Q000097:blood*; D011687:Purines; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000097:blood*
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate