B-Cyclodextrine Modified Carbon Paste Electrode as a Selective Sensor for Determination of Piroxicam Using Flow Injection Cyclic Voltammerty

A carbon paste electrode was modified with ?-cyclodextrin to form a selectiveelectrochemical sensor for determination of piroxicam (px). a novel sensitive techniquewhich called fast fourier transform cyclic voltammetry (fft cv) was used formeasurements of redox current of the component. to have a more defined and intense peakcurrent for piroxicam determination, tris-hcl buffer (ph=8.0; 0.05 mol l-1) was used assupporting electrolyte. in this aqueous media, px has been selectively accumulated on thesurface of electrode by cd as a modifier. the drug presented one irreversible oxidationpeaks at about 500 mv on modified carbon paste electrode vs. ag/agcl which produced ahigher current. this property was used for analytical purposes by developing a strippingfftcv method to determine piroxicam. furthermore, signal-to-noise ratio has significantlyincreased by application of discrete fast fourier transform (fft) method, backgroundsubtraction and two-dimensional integration of the electrode response over a selectedpotential range and time window. the effective parameters were optimized. as a result, cdlof 5.0×10-9 mol l-1 and loq of 8.0×10-9 mol l-1 were obtained. the electrode applied fordetermination of px in urine and plasma and formulation samples. the recovery for spikedassay in urine and plasma samples was obtained 101-105% respectively and a goodquantification of piroxicam was achieved in a commercial formulation. the effect of someinterfering substances was investigated and electrode showed a good selectivity to piroxicam.