Construction and performance characterization of screen printed and carbon paste ion selective electrodes for potentiometric determination of naphazoline hydrochloride in pharmaceutical preparations

Abstract

This paper describes the development of screen-printed (SPE) and carbon paste (CPE) sensors for the rapid and sensitive quantification of naphazoline hydrochloride (NPZ) in pharmaceutical formulations. This work compares the electroactivity of conventional carbon paste and screen-printed carbon paste electrodes towards potentiometric titration of NPZ. The repeatability and accuracy of measurements performed in the analysis of these pharmaceutical matrices using new screen printed sensors were evaluated. The influence of the electrode composition, conditioning time of the electrode and pH of the test solution, on the electrode performance were investigated. The drug electrode showed Nernstain responses in the concentration range from 1 × 10(-6) to 1 × 10(-2) mol L(-1) with slopes of 57.5 ± 1.3 and 55.9 ± 1.6 mV per decade for SPE and CPE, respectively, and was found to be very precise and usable within the pH range 3-8. These sensors exhibited a fast response time (about 3 s for both SPE and CPE, respectively), a low detection limit (3.5 × 10(-6) and 1.5 × 10(-6) M for SPE and CPE, respectively), a long lifetime (3 and 2 months for SPE and CPE, respectively) and good stability. The selectivity of the electrode toward a large number of inorganic cations, sugars and amino acids was tested. It was applied to potentiometric determination of NPZ in pure state and pharmaceutical preparation under batch conditions. The percentage recovery values for the assay of NPZ in tablets (relative standard deviations ≤0.3% for n = 4) were compared well with those obtained by the official method.

Evidence on the 2-nitrophenyl octyl ether (NPOE) facilitating Copper(II) transport through polymer inclusion membranes

“…The perpendicular dotted line was used as marked line to illustrate the peak shifts of -CHCl-group. Compared with the individual PVC membrane, the binding energy of -CHCl-groups increases by 0.3 eV for the PIMs consisting of 70 wt% PVC and 30 wt% LIX 84I, indicating that electron density of carbon atom in -CHCl groups is weakened [37][38][39]. Namely, the molecular interactions between PVC and LIX 84I, such as hydrogen bonding and Van der Waals forces, are established.…”

Lanthanum(III) potentiometric sensors based on ethyl benzoyl acetate

“…SPEs were printed in arrays of six couples consisting of the working electrodes (each 5x 35 mm) following the procedures previously described [20][21][22][23][24][25][26]. A polyvinyl chloride flexible sheet (0.2 mm) was used as a substrate which was not affected by the curing temperature or the ink solvent and easily cut by scissors.…”

Electroanalytical determination of sildenafil in Viagra tablets using screen-printed and conventional carbon paste electrodes

“…The wire was polished, carefully cleaned in strong ammonia solution, rinsed, carefully dipped in 50% nitric acid for 1 min, rinsed with distilled water but do not dry. The wire was cathodized [26] against a sliver anode at 5 mA/cm 2 in 0.1 mol L À1 HCl for 30 s, the bubble was allowed to disperse from the wire and the electrode was washed and left to dry. The electrode was immersed in the cocktail consisting of (240 mg o-NPOE + 240 mg PVC + 6 mL THF) 20 times and after each the solvent evaporated using air gun.…”

“…The screen printed carbon paste electrodes are fabricated as previously reported by the research group [26]. In order to assess the validity of the prepared electrodes, the potentiometric titration methods are applied for the determination of SILC in pharmaceutical preparation using SPE and CPE plasticized with DBP, TCP and o-NPOE.…”