Supercritical fluid chromatography-tandem mass spectrometry for the enantioselective determination of propranolol and pindolol in mouse blood by serial sampling.

Packed-column supercritical fluid chromatography (pSFC) coupled to an atmospheric pressure chemical ionization (APCI) source and a tandem mass spectrometer (MS/MS) with minimum sample pretreatment was explored for the rapid and enantioselective determination of (R,S)-propranolol in mouse blood. Serial bleeding of mice is advantageous for the reduction of animal usage, dosing errors, and animal-to-animal variation. The effects of the eluent flow rate and composition as well as the nebulizer temperatures on the ionization efficiency of racemic propranolol and pindolol as model compounds in the positive ion mode under pSFC conditions were studied. The fundamental parameters on the proposed hyphenated system such as matrix ionization suppression and chromatographic performances were investigated in improving sensitivity and enantiomeric separation for the detection of the analytes. The proposed chiral pSFC-APCI/MS/MS approach requiring approximately 3 min/sample for the determination of (R,S)-propranolol at a low nanogram per milliliter region was partially validated with respect to specificity, linearity, reproducibility, and accuracy and was applied to support a pharmacokinetic study.