ABSTRACT
In this research, a new approach based on magnetic electrodes has been developed for the determination of per-fluorooctane sulfonic acid (PSOF). Zinc and Titanium-based Metal-organic framework (MOF) was synthesized and used with polypyrrole as a conductive polymer for preparation of the absorbent to achieve the best performance for electrochemical application. The response of the electrode for determination of the PFOS was affected and optimized by different factors such as buffer solution, pH of the solution, amount of absorbent, extraction time of absorbent, accumulation time, as well as the Square Wave Voltammetry (SWV) instrumental parameters including voltage step, pulse amplitude, frequency and resting time. In the optimum condition, the response of the Zn/Ti/C-MOF-magnetic molecular imprinting polymer/carbon paste electrode (MOFMMIP/CPE) has increased logarithmically by increasing the concentration in the range of 0.002-165 µM by the limit of detection (LOD) of 0.7 nM. The obtained percentage of Recovery (96.00-104.14 %), Bias (-4.00 - 4.14 %) and Relative Standard Deviation (RSD) (1.89-3.74 %) for determination of the PFOS in real and spiked tap water, river water and well water samples demonstrates that the proposed method has an acceptable precision. The comparison between the gained data by the presented method and High-performance liquid chromatography (HPLC) showed that the presented method has high accuracy.
ABSTRACT
BACKGROUND: The combination of estradiol cypionate (ECA) and medroxyprogesterone acetate (MPA) is used to prevent pregnancy in women. The analysis of the ECA and MPA combination reveals a challenge due to the strong overlap of the spectra of these compounds. OBJECTIVE: Spectrophotometry techniques along with chemometrics methods are simple, fast, precise, and low-cost for the simultaneous determination of ECA and MPA in a combined pharmaceutical dosage form. METHODS: Two developed approaches, the least-squares support vector machine (LSSVM) and fuzzy inference system (FIS), along with a spectrophotometric method were proposed to solve such a challenging overlap. RESULTS: Based on the cross-validation method, the regularization parameter (γ) and width of the function (σ) in the LSSVM model were optimized and the root mean square error (RMSE) values were found to be 0.3957 and 0.2839 for ECA and MDA, respectively. The mean recovery values were 99.87 and 99.63% for ECA and MDA, respectively. The FIS coupled with principal component analysis (PCA) showed mean recovery percentages equal to 99.05 and 99.50% for ECA and MDA, respectively. Also, the RMSE of both components was lower than 0.3. CONCLUSION: The analysis results of a real sample (injection suspension) using the proposed methods were compared with HPLC by a one-way analysis of variance (ANOVA) test, and no significant differences were found in the results. HIGHLIGHTS: Intelligent methods were proposed for the simultaneous determination of ECA and MPA. The least-squares support vector machine and fuzzy inference system along with spectrophotometry were used. HPLC as a reference method was performed and compared with chemometrics methods. The benefits of the proposed approaches are that they are rapid, simple, low-cost, and accurate.
Subject(s)
Medroxyprogesterone Acetate , Support Vector Machine , Pregnancy , Female , Humans , Chromatography, High Pressure Liquid , Estradiol , Spectrophotometry , Least-Squares AnalysisABSTRACT
BACKGROUND: Chromatographic methods have been used for the simultaneous determination of salmeterol (SMT) and fluticasone (FLU). The methods take a lot of analysis time, need sample pre-treatment and large amounts of solvents, and are costly. OBJECTIVE: The aim of this paper was to propose a simple, quick, and low-cost method for the determination of SMT and FLU using a time series neural network and multivariate calibration methods, including partial least-squares (PLS) and principal component regression (PCR). METHODS: The simultaneous spectrophotometric determination of SMT and FLU in binary mixtures and anti-asthma spray was performed by applying multivariate calibration methods and an intelligent approach. RESULTS: The coefficient of determination (R2) of the time series neural network was obtained: 1 and 0.9997 for SMT and FLU, respectively. The mean recovery of PLS was found to be 99.29% and 99.84% for SMT and FLU, respectively. Also, the mean recovery related to the PCR method was 102.05% and 103.72% for SMT and FLU, respectively. CONCLUSION: The inhalation spray was assessed using HPLC and the results were compared with chemometrics methods via an analysis of variance (ANOVA) test. HIGHLIGHTS: Intelligent and multivariate calibration methods were proposed. Simultaneous spectrophotometric determination of salmeterol and fluticasone was studied in an anti-asthma spray. HPLC as a reference method was performed and compared with chemometrics methods. Rapid, simple, low-cost, and accurate are the benefits of the proposed approaches.
Subject(s)
Neural Networks, Computer , Fluticasone , Salmeterol Xinafoate , Calibration , Chromatography, High Pressure Liquid , Time Factors , Spectrophotometry/methods , Least-Squares AnalysisABSTRACT
Naproxen sodium (NAP) and Sumatriptan (SUM) are pharmacological migraine therapies that are more efficient when administered in combination. In the present work, an electrochemical sensor was developed for simultaneous and sensitive NAP and SUM detection using MWCNTs decorated with ZnO, NiO and Fe3O4 nanoparticles on glassy carbon electrode (GCE). This report is the first research on simultaneous electrochemical measuring the target drugs based on the literature. The data show that modification of the GCE surface with ZnO/NiO/Fe3O4/MWCNTs nanocomposite remarkably improves the electro-oxidation peaks currents but the peaks potential of NAP and SUM have shifted to the lower potential which demonstrates that electro-oxidation of target drugs have done more easier than GCE at the surface of modified electrode. The nanocomposite was recognized by using Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD). The improved electrode was estimated by various methods, including cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS) techniques. Influencing parameters containing the supporting electrolytes, pH, scan rate, deposition potential, and accumulation time were optimized. The linear detection ranges were from 4.00 nMto 350.00 µM for NAP and from 6.00 nM to 380.00 µM for SUM, with the detection limits of 3.00 nMfor NAP and 2.00 nM for SUM, respectively. The repeatability, linearity, and selectivity of ZnO/NiO/Fe3O4/MWCNTs/GCE were investigated, and the received outcomes divulged the efficiency of the electrode. The consequence of high-performance liquid chromatography (HPLC) and recovery show the method's suitability for the simultaneous determination of NAP and SUM in the biological fluids and pharmaceutical compounds.