PVC supported liquid membrane and carbon paste potentiometric sensors incorporating an Mn(III)-porphyrin
complex as a neutral host molecule were developed for the determination of paracetamol. The measurements were
carried out in solution at pH 5.5. Under such conditions paracetamol exists as a neutral molecule. The mechanism of
molecular recognition between the Mn(III)-porphyrin and paracetamol, leading to potentiometric signal generation,
is discussed.The sensitivity and selectivity toward paracetamol of carbon paste and polymeric liquid membrane electrodes
incorporating an Mn(III)-porphyrin host were compared. The applicability of these sensors to the direct
determination of paracetamol was checked by performing a recovery test in human plasma.