Determination of naphazoline hydrochloride in biological and pharmaceutical samples by a quantum dot‐assisted chemiluminescence system using response‐surface methodology

Abstract

A simple and highly sensitive chemiluminescence (CL) method is reported for the determination of naphazoline hydrochloride (NH). It was found that the weak CL from the reaction of luminol and KIO4 in an alkaline medium could be highly amplified by cysteine-capped cadmium telluride quantum dots (QDs) and the enhanced CL was effectively quenched by NH and this finding was utilized as a basis for the determination of NH. The QDs were synthesized in aqueous medium and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-vis and photoluminescence spectroscopy. A possible mechanism was proposed for the CL system based on radical identification experiments, along with CL spectrum of the system. The experimental parameters were optimized by the reliable response surface methodology (RSM). Under the optimized experimental conditions, the proposed method allowed the determination of NH over the range of 5.0 × 10(-10) -2.0 × 10(-7) mol/L (r(2) = 0.9993, n = 10). The precision (RSD%) of the method, obtained from five replicate determinations of 2.0 and 150 nmol/L NH, was found to be 1.0% and 1.3%, respectively. The method was successfully applied to the determination of NH in pharmaceutical formulations and human urine and serum samples with results corroborated with the aid of those obtained from a standard method.

A Novel Fluorimetric Method for Determination of Pseudoephedrine Hydrochloride in Pharmaceutical Formulations and Blood Serum

“…Serum samples were prepared according to a reported procedure [19]. In brief, a 1.00 mL aliquot of serum was transferred into a centrifuge vessel and 2.00 mL of 0.1 M Ba(OH) 2 and 2.00 mL of 0.1 M ZnSO 4 were added to precipitate the proteins.…”

“…The response surface methodology is a clever combination of techniques that take root in mathematics and statistics used for solving various optimization problems. It helps researchers find the global optimum conditions of the system rather than any likely local optima [19][20][21]. The present study takes advantage of central composite design (CCD), a widely used version of RSM [19,20], for optimizing the analysis conditions in terms of achieving the largest possible ∆F values.…”

“…It helps researchers find the global optimum conditions of the system rather than any likely local optima [19][20][21]. The present study takes advantage of central composite design (CCD), a widely used version of RSM [19,20], for optimizing the analysis conditions in terms of achieving the largest possible ∆F values. Constructing a table of design and statistical analyses of the obtained results was done by Minitab ® 15 software.…”

“…The total number of design experiments was 19 (for n = 3). Prior to any mathematical analyses, the variables X i were transformed into coded ones, x i , according to equation (3) [19]:…”

“…The proposed method can be used independently or in conjunction with various chromatographic or CE methods as their detection system. The method was optimized by the response-surface method (RSM), which is a powerful multivariable analysis tool that can provide us with a global optimum condition of the system and can reveal any possible interactions between the investigated experimental factors [19][20][21].…”