A Novel Flow-Injection Potentiometric Detector for Determination of Tamoxifen in Anticancer Drug Formulations

摘要

A flow-injection potentiometric detector was reported for the rapid determination of tamoxifen (TAM), by using a poly(vinyl chloride) (PVC) membrane electrode containing tamoxifen-phosphomolibdate (TAM-PM) ion-pair as electroactive component. The potentiometric quality of the electrode response was optimized. Under the optimized condition (carrier solution: 5.0 × 10~(-7) M TAM, injection volume: 20 μL, flow-rate: 2.0 mL min~(-1), tubing length: 10 cm), the calibration plot for TAM was linear over the concentration range of 1.0 × 10~(-4)-1.0 × 10~(-2) M with a sub-Nernstian slope of 37.7 mV per decade of TAM activity and detection limit of 4.2 × 10~(-5) M. The interference effects of some common alkaline metal, alkaline earth metal, heavy metals, organic and pharmaceutical molecules on electrode response were investigated and selectivity coefficients were calculated. The relative standard deviation of the electrode response for thirteen replicate measurements of 5.0 × 10~(-4) M TAM was 1.81%. The flow-through detector system revealed sampling rates of approximately 90 injections per hour depending on the TAM concentration of the injected sample. The offered potentiometric flow-injection system was applied for the determination of TAM in pharmaceutical preparations and the obtained results were compared with High-Performance Liquid Chromatography (HPLC) results.