Simultaneous determination of blockers and agonists by on-fiber derivatization in self-made solid-phase microextraction coating fiber.

An environmentally friendly and sensitive method for determination of blockers and agonists was described in this paper. The method is based on a homemade sol-gel solid-phase microextraction (SPME) coating with simultaneous on-fiber derivatization and subsequent gas chromatography mass spectrometry (GC/MS) analysis. The influences of the main factors on the type and thickness of the homemade fiber coatings, conditions of the derivatization, extraction and desorption of SPME were investigated in detail. The proposed procedure showed limits of detection lower than 0.2 ng mL(-1). The linearity was in the 0.5-150 ng mL(-1) for clenbuterol and 1.0-100 ng mL(-1) for metoprolol and propranolol. The variation in measurements (repeatability) was below 8.7% (n=6) and the degree of difference between (reproducibility) was below 11.4% (n=3). In the application, spiked human saliva samples and real human saliva samples were analyzed, it was found that saliva would affect the detection of propranolol when it was a very low content. The established method can be feasible in practical application and helpful for agonists and blockers preliminary screening during the competition.