Development of new potentiometric sensors for the determination of proguanil hydrochloride in serum and urine

Potentiometric electrodes were developed for the rapid determination of proguanil hydrochloride in pure samples, pharmaceutical preparations and spiked serum and urine samples using PVC membrane, screen printed (SPE), coated wired (CWE), carbon paste (CPE) and modified carbon paste (MCPE) electrodes based on the ion-exchanger of proguanil with phosphotungestic acid (Pr-PT) as a chemical modifier. The prepared electrodes showed Nernestian slopes of 59.7, 58.1, 58.5, 58.5 and 57.0 for the PVC, SPE, CWE, CPE and MCPE for the proguanil ions in a wide concentration range of 1.0×10^-6-1.0×10^-2 mol L^-1 at 25 ℃ with detection limits of 7.94×10^-6, 1.0×10^-6, 1.0×10^-6, 7.07×10^-6 and 2.5×10^-6 mol L^-1, respectively. The prepared electrodes exhibited high proguanil selectivity in relation to several inorganic ions and sugars and they could be successfully utilized for its determination in pure solutions, pharmaceutical preparations and serum and urine samples using the direct potentiometry and standard addition methods with very good recovery values.