title: Polyvinyl chloride matrix membrane electrodes for manual and flow injection analysis of chloroquine in pharmaceutical preparations.
abstract: Two types of polyvinyl chloride (PVC) matrix membrane electrodes responsive to the antimalarial drug chloroquine have been constructed, electrochemically evaluated, compared and used in pharmaceutical analysis. Type 1 is the classic PVC model with chloroquine-tetraphenylborate (TPB) sensor; Type 2 is a coated silver disk without internal filling solution. Both electrode types exhibited rapid linear potentiometric response to the logarithmic concentration of diprotonated chloroquine cation in the 10(-1) - 10(-6)M range with calibration slopes 28-30 mV/concentration decade over the pH range 1.8-6.2. These electrodes were sensitive enough to permit determination of chloroquine phosphate at concentrations as low as 5 microgram/mL with good accuracy and precision. Determination of chloroquine in various pharmaceutical preparations using direct potentiometry and potentiometric titration with NaTPB gave an average recovery of 98.8% of the nominal values (SD 0.5%). The Type 2 electrode was also assessed in a flow-through sandwich cell for flow injection analysis. Results were compared with data obtained by the U.S. Pharmacopeia method.
authors.affiliation: Ain Shams University, Department of Chemistry, Cairo, Egypt.
authors.forename: S S
authors.initials: SS
authors.lastname: Hassan
authors.forename: M A
authors.initials: MA
authors.lastname: Ahmed
mesh_terms: D002738:Chloroquine / Q000032:analysis*; D004566:Electrodes; D008832:Microchemistry; D011143:Polyvinyl Chloride; D011199:Potentiometry / Q000706:statistics & numerical data
chemical_list: D002738:Chloroquine; D011143:Polyvinyl Chloride