The use of beta-blockers to enhance performance in some sports is forbidden. Based on this regulation, there is a demand for dynamic analytical procedures for analyzing these compounds quickly and without manual sample preparation. Therefore, the use of a molecularly imprinted polymer (MIP) in a multidimensional liquid chromatographic system coupled to a mass spectrometer provides a good alternative for improving the selectivity and practicality of the beta-blocker analyses, as described in this paper. A water-compatible MIP for oxprenolol was synthesized by the precipitation method, using methacrylic acid as a functional monomer and 2-hydroxyethyl methacrylate and glycerol dimethacrylate as hydrophilic monomers. A column filled with MIP was coupled to an LC-MS/MS instrument under the multidimensional configuration, with 10.0 mmol L⁻¹ ammonium formate buffer (pH 5.0) as the loading and reconditioning mobile phase and a 0.01% formic acid aqueous solution–methanol (30 : 70 v : v) as the elution mobile phase. The system was used for on-line extraction and quantization of oxprenolol (from 1.0 to 75.0 μg L⁻¹), atenolol, propranolol, nadolol, pindolol, labetalol and metoprolol (all from 3.0 to 50 μg L⁻¹) simultaneously, from urine samples. The correlation coefficient was higher than 0.99 for all the analytes. Suitable precision and accuracy were obtained.

In this article, we proposed a new restricted access molecularly imprinted polymer coated with bovine serum albumin (RAMIP-BSA) to be used in a multidimensional chromatographic system applied for the analysis of six selective serotonin reuptake inhibitors (SSRIs) directly from untreated human plasma samples. Fluoxetine, methacrylic acid and ethylene glycol dimethacrylate were used as the template, functional monomer and cross-linker, respectively. The imprinted polymer was covered with a bovine serum albumin (BSA) layer via the interconnections between the amine groups of the BSA using glutaraldehyde as a cross-linker. The obtained RAMIP-BSA was able to extract the SSRIs directly from the human plasma, while ∼100% of the proteins were excluded from the sample. Selectivity coefficients were calculated for fluoxetine (template) in comparison with venlafaxine, duloxetine, citalopram, fluvoxamine, paroxetine and sertraline, and the values were >1 in all cases, attesting to the presence of binding sites in the imprinted polymer. The method presented analytical ranges from 20 to 500 µg/L and correlation coefficients >0.99 for all of the SSRIs (fluoxetine, venlafaxine, duloxetine, citalopram, fluvoxamine and sertraline). Precision and accuracy presented variation coefficients and relative errors 85%. The proposed method was able to analyze three samples per hour, and each column was used at least 50 times without any significant changes in its performance.