Dedicated to professor Pier Giorgio Zambonin on the occasion of his 80th birthday.
1Introductionb-blockers,a lso called b-adrenergic antagonists such as: propranolol( Pp), atenolol( At), nadolol (Nd), bisoprolol, etc. are of therapeutic interest in the treatment of various cardiovasculard isorders,a ngina pectoris,c ardiaca rrhythmia, hypertension and associated pathologies,e tc. [1][2][3]. Thep ropranolol, 1-(isopropylamino)-3-(1-naphthyloxy)-2-propanol, is consideredt he prototype drug of b-adrenergic blockers.I ts main medicalu se has changed, in the last years,f rom therapyo fc ardiovascular diseases to therapy of infantile haemangiomas in pediatric patients.I nf act, Pp orally administered, has ac onsistent and rapid therapeutic effect, leadingt oc onsiderable shortening of the naturalc ourse of infantile haemangiomas with good clinical tolerance.I na ddition, this therapeutic drugc ould also be usedi ns ome sports requiringi ntensec oncentration as ad oping agent [4].I nt his respect, the International Olympic Committee has classified the Pp as doping specie and has includedi nalist of forbidden substances.Although these b-blockers are widely used in many therapeutic contexts,h igh plasma concentration of the Pp,N d, At, etc. can cause severe respiratoryp roblems such as asthma, adult respiratory distress syndromea nd heart failure [5].I np articular,a tenolol can be associated with an increasedr isk of diabetesm ellitus and increased risk of stroke [6].T hus,t hese drugs require continuous monitoring in biological fluids and/or pharmaceutical formulations for adjusting the corresponding dose in order to preventh azardouse ffects on health.Substantial amounts of these pharmaceuticals and their metabolitesg et into the wastewater after excretion and finallyi ns urface water due to an incomplete eliminationi n wastewater treatments.I nt his respect, recent ecotoxicological studies show that several aquatic organisms are sensitive to the presence of some b-blockers and/ort heir derivatives [7].Inparticular, the contact of hospital pollutantsw ith aquatic ecosystems leads to as evere risk on biological balance of natural environments.O nt he basis of these considerations,s imple,s ensitive,a ccurate and inexpensivea nalytical methodologies for quantification of thesec ompounds in biological fluids,e nvironmentalc ontextsa nd pharmaceutical formulations is required.Numerous analytical methods proposed for the determination of the common b-blockers in variousc ontexts are mainly based on reverse-phase liquid chromatography generally coupled with spectrophotometric UV-Vis detection,f luorescence or mass spectrometryd evices used as on-line detectors [8][9][10][11][12][13]. Other analyticalm ethodologies basedo nc hemiluminescence measurements [14],d iffuse Abstract:T he electroanalyticalc haracterizationa nd determinationo ft hree selected b-blocker agents,n amely propranolol, atenolol and nadolol usingc yclic voltammetry and differential pulse voltammetry (DPV) in phosphate buffer solution (pH 2.5) plus 22 %a cet...