Flow-batch analysis method for the determination of trace levels of clenbuterol in urine samples using MIPs and Griess reaction

CAROLINA C. ACEBAL; ADRIANA G. LISTA; PETR SOLICH; IVANA SRÁMKOVÁ; NATALIA GONZALEZ; MARCOS GRUNHUT; BURKHARD HORSTKOTTE; BEATRIZ S. FERNÁNDEZ BAND; HANA SKLENÁROVÁ

Palma de Mallorca

Conferencia; 20th International Conference on Flow Injection Analysis and Related Techniques (20th ICFIA); 2016

Clenbuterol (CLE) is a well-known beta-agonist which is being used in animal husbandry and sports for growth promoting purposes. The aim of this work was to develop a flow-batch analysis (FBA) method for the determination of trace levels of CLE in urine samples. To achieve preconcentration of the analyte, a ommercialmolecularly imprinted polymer (MIP, Supelco) was used to fill a short SPE column. A colorimetric determination based on the Griess reaction was employed to quantify the analyte. Briefly, the FBA system consists of 5 channels methanol, water, buffer pH 6.7, sample, acetonitrile 70%) connected to theMIP-SPE column. Besides, two additional channels for the reagents (NaNO2 + HCl and NED) were connected directly to the flow-batch chamber (FBC) where the eluate merged with the reagents and the spectrophotometric detection at 500 nm was performed. The physical and chemical variables of the MIPSPE-FBA system were studied: Volume of sample (5.0 mL), volume of the eluent (500 µL), flow rates ofloading and eluting steps (0.6 mL min-1), volumes and concentrations of Griess reagents (125µL NaNO2 0.64 mM; 300µL HCl 4.6 M; 250 µL NED 0.68 mM). The calibration curve was constructed over the range of 75 to 500 µg mL-1 (n=5). The method was applied to the CLE determination in human urine samples.AcknowledgementsThe authors acknowledge financial support of bilateral cooperation project, MINCyT-MEYS No. ARC/13/09(7AMB14AR029).