Automated solid phase preconcentration with fluorescence detection for sildenafil determination

WANG CHIEN CHUN; SOMBRA LORENA; FERNÁNDEZ, LILIANA P.

ANALYTICA CHIMICA ACTA

ELSEVIER SCIENCE BV

Año: 2011

0003-2670

In this work, Amberlite XAD-1180 resin is proposed for on-line surfactant-mediated preconcentration of sildenafil as previous step of its fluorescent detection. Cationic surfactant (hexadecyltrimethylammonium bromide, HTAB) is adsorbed onto the resin in order to activate the column for sildenafil pre-concentration. Sildenafil retention by HTAB-resin occurs at alkaline aqueous medium and is then eluted by ethanol and analyzed by spectrofluorimetry. Drug-surfactant association produces considerable fluorescence enhancement, which increases even more the sensitivity of detection. Thus, sildenafil can be preconcentrated and quantitatively determined, with detection limit of 0.2 ng mL-1. The proposed method was successfully applied to the analysis of bulk drug, human urine, and local herbal medicine. Validation processes were performed by recovering study and statistical analysis with satisfactory results.