Zorbax 80sb 5 μm c18 phase

Dexfenfluramine and pergolide concentrations in rabbit serum were determined by liquid chromatography coupled with mass spectrometry (LC–Chip–MS/MS). Briefly, the chromatographic separation was achieved on a 1200 series LC-chip system (Agilent Technologies, Germany) using an Ultra High Capacity chip including a 500 nL trapping column and a 150 mm × 75 μm analytical column, both packed with a Zorbax 80SB 5 μm C₁₈ phase (Agilent Technologies). The mobile phase was composed of H₂O/FA (100:0.1, v/v) (A) and ACN/H₂O/FA (90:10:0.1, v/v/v) (B) and used in gradient elution mode (from 15% to 69% B in 5 min). Mass spectrometric detection was performed using a 6340 Ion Trap equipped with a nanoelectrospray ionization source operating in positive mode (Agilent Technologies, Waldbronn) (transitions followed for dexfenfluramine: 232.0 −> 158.8; 186.8 m/z and for pergolide: 315.2 −> 207.9; 267.0 m/z). Finally, an Oasis µElution MCX 96-well plate (Waters, UK) was used to prepare the samples for the analysis. Fifty microliters of plasma was needed per experiment and all conditions were performed in duplicate and back-calculated using a calibration curve.

Drug concentrations were determined from serum using liquid chromatography coupled with mass spectrometry (LC-Chip-MS/MS) that was used as previously described [22 (link), 33 , 34 (link)]. Briefly, the chromatographic separation was achieved on a 1200 series LC-chip system (Agilent Technologies, Germany) using an ultrahigh capacity chip including a 500 nL trapping column and a 150 mm × 75 μm analytical column, both packed with a Zorbax 80SB 5 μm C18 phase (Agilent Technologies). The mobile phase was composed of H₂O/FA (100 : 0.1, v/v) (A) and ACN/H₂O/FA (90 : 10 : 0.1, v/v/v) (B) and used in gradient elution mode. Mass spectrometric detection was performed using a 6340 ion trap equipped with a nanoelectrospray ionization source operating in positive mode (Agilent Technologies, Waldbronn). Finally, an Oasis μElution MCX 96-well plate (Waters, UK) was used to prepare the samples for the analysis. All conditions were performed in duplicate and back-calculated using a calibration curve. Fluoxetine and norfluoxetine levels were averaged across days to provide one morning and one afternoon value.