The LC-MS/MS system consisted of a Thermo Fisher Scientific TSQ
Vantage triple quadropole mass spectrometer connected to a Dionex
Ultima3000UHPLC. The liquid chromatography systemcomprised Ultimate
2000 SRD degasser, Ultimate 3000 RS binary solvent pump system,
column oven and Ultimate 3000 RS autosampler. The softwares
used were Chromeleon Xpress v. 3, TraceFinder Clinical Research v. 2.1
and ThermoTSQ Tune Master v. 2.3.0. Identifications were based on correct
relative retention time (±0.5%) and product ion ratio (±20%).