DIFFERENTIAL-PULSE ADSORPTIVE STRIPPING VOLTAMMETRY OF CHLORHEXIDINE

Chlorhexidine gluconate was shown to adsorb onto a hanging mercury drop electrode and to be amenable to quantification by adsorptive stripping voltammetry. A sensitivity of 1 x 10(-7) mol dm-3 was easily achieved by simply immersing the electrode in a stirred solution (pH 9.7 ammonia-ammonium acetate buffer) of the drug for a fixed time (60 s), at a suitable potential (0.0 V versus Ag-AgCl), and then stripping cathodically in the differential-pulse mode. The stripping peak potential was -1.53 V. Cyclic voltammetry was used to test the interfacial and redox behaviour. Chlorhexidine gluconate was assayed in mouthrinse and contact lens solution dosage forms.