DI-SPME/LC–MS/MS approach for the determination of multiple drugs and their metabolites across thirteen rabbit biological matrices

The object of this publication was to test the applicability of an existing DI-SPME/LC-MS/MS method for the analysis of samples of thirteen biological materials collected from rabbits (brain, cerebellum, vitreous humour, cardiac muscle, blood, lung, liver, spleen, bile, kidney, urine, bone marrow and thigh muscle) for the presence of diazepam, citalopram, carbamazepine, venlafaxine, morphine, alprazolam and their selected metabolites. For this purpose, full validation was performed for nine matrices. In the case of cerebellum, vitreous humour, bone marrow and bile, the amount of available blank matrices was insufficient, so cerebellum samples were referred to calibration graphs prepared for brain and the others to graphs prepared with saline. Validation studies determined LOD and LOQ (respectively <1.2 ng/mL and <3.5 ng/mL for liquid samples and <4.5 ng/g and <13.5 ng/g for solid samples), precision within and between days (0.1–19.5%), and relative error (|RE|<12.7%) and recovery (within 80.0–110.0% for most analytes). A study of the matrix effect was also carried out and showed its presence in several cases. The suitability of the method was also confirmed by analysing a number of real samples. In addition to analytical aspects, the greenness and practicality of the method were also discussed based on the principles of green analytical chemistry, the blue applicability grade index tool and White Analytical Chemistry concept. • DI-SPME/UPLC-MS/MS method for the analysis of samples of thirteen biological materials. • The animal model used in the study enabled controlled analysis of the presence of the test compounds. • Useful tool that can be used both in routine analyses using blood or urine and alternative matrix. • Pharmaceutical analysis by using real samples.