LAUSR

Abstract Variations in endogenous levels of catecholamines may be caused by changes in the organism, which are associated with the development of certain diseases by exogenous sources that are related to the intentional administration of some catecholamine. This study presents the development, validation and application of an analytical method to detect and to analyze the catecholamines and its metabolites simultaneously. The sample extraction consisted basically in hydrolysis and solid-phase extraction using a weak cation exchange functionalized polymeric sorbent cartridges. The catecholamines analysis was performed on orbitrap high resolution mass spectrometry HRMS-orbitrap equipped with electrospray. Modifications in different electrospray variables (S-lens, sheath gas flow and capillary temperature) were performed following the Doehlert experimental design (DOI). The validation parameters evaluated were repeatability, intermediate precision, matrix interference, limit of quantification, linearity, carryover and robustness. The most favorable conditions found according to the DOI for all analytes were S-lens fixed at 80 rf, sheath gas flow at 20 au and capillary temperature at 300 °C. The repeatability obtained from 100%, intermediate precision was 70%, matrix interference was observed, limit of quantification of the 5 ng·mL−1, linearity was 80%, robustness was 80% and carryover was not observed. DOI showed the most favorable conditions for the analysis of all the target compounds, contributing to the establishment of the method parameters. When applied in real samples, the method proved to be rapid, sensitive and selective even in the presence of urine interferents.