LC-MS/MS Estimation of Propranolol level in Exhaled Breath Condensate

Background: Exhaled breath condensate (EBC) could be used as a non-invasive and alternative specimen to urine and blood for monitoring propranolol levels. A simple, sensitive and selective liquid chromatography–tandem mass spectrometry (LC–MS/MS) method is employed for the determination of propranolol in EBC samples. Methods: Samples directly injected to a C18 analytical column and isocratically separated using a mobile phase composed of methanol + acetic acid (99:1 v/v). Detection was performed by positive electrospray ionization in multiple reaction monitoring and selected ion recording modes. Results: The chromatographic separation was obtained within 6.0 min and was linear over the concentration range of 5.6–224.0 ng/mL (R2 = 0.999). The accuracy and precision of the method were within 15% according to FDA guideline. The found concentrations of propranolol in EBC of two patients receiving 80 mg/day were 30 and 40 ng/mL. Conclusion: Developed method was applied to determine propranolol levels in three patients receiving propranolol in their medication. The obtained propranolol levels in EBC could be used to develop simpler, cheaper and more feasible analytical methods to be used in routine analysis of propranolol in biomedical analytical laboratories.