Oxidation Of Naproxen Research Articles

An effective, novel, and cheap carbon paste electrode for naproxen estimation

AbstractHerein, a carbon paste electrode (CPE) modified with poly(reduced-o-nitrobenzoic acid [r-o-NBA]) supported in graphene quantum dots (GQDs) was fabricated for the first time. The fabricated electrode’s surface morphology and composition were characterised by scanning electron microscope and transmission electron microscope. The poly(r-o-NBA)/GQDs/CPE showed high electrocatalytic activity towards the oxidation of naproxen (NPX) using cyclic and differential pulse voltammetric methods. The effect of scan rate on the oxidation peak of NPX suggests that the electrode process was typically diffusion-controlled. In addition, the effect of pH reflects the participation of protons in the oxidation process of NPX. The peak current is linearly proportional to the concentration of NPX ranging from 1.0 to 100.0 µM, with the correlation coefficient (R2), sensitivity, limit of detection (3σ), and limit of quantification (10σ) being 0.9995, 0.419 µA·µM−1·cm−2, 0.672, and 2.241 µM, respectively. Using chronoamperometry, the diffusion coefficient of NPX at the poly(r-o-NBA)/GQDs/CPE was estimated to be 5.36 × 10−6 cm2·s−1. The proposed electrode has good reproducibility, stability, and high selectivity for NPX oxidation. The obtained recovery range (96.7–102.0%) means that the proposed sensor performed satisfactorily when applied for the detection of NPX in its pharmaceutical formulations.

3D-printed carbon black/polylactic acid electrochemical sensor combined with batch injection analysis: A cost-effective and portable tool for naproxen sensing

Additive manufacturing has emerged as an innovative technology for the large-scale development of low-cost and disposable electrochemical devices. Hence, in this paper, we highlight the use of a 3D-printed electrode using carbon black integrated polylactic acid (CB/PLA) conductive filament for electrochemical detection of naproxen (NPX), a highly consumed non-steroidal anti-inflammatory drug used in the treatment of rheumatoid arthritis, osteoarthritis, nonrheumatic inflammation, and migraine. Two designs of electrodes were fabricated using an extrusion-based 3D printer and a 3D pen (cylindrical and planar shapes) and both required only simple electrochemical surface treatment to improve their electrochemical activity towards the oxidation of NPX. The planar-shape sensor was incorporated into a 3D-printed Batch-injection analysis (BIA) cell to carry out amperometric detection (+1.3 V vs. Ag|AgCl|KCl(sat)) which provided sensing features comparable to more sophisticated sensors reported in the literature for NPX detection. Characteristics such as linear range (2 to 50 µmol L-1), limit of detection (0.9 µmol L-1), precision (RSD less than 6.7%, n = 20), high analytical frequency (105 injections h−1), and selectivity in relation to other electroactive species were achieved. Moreover, the method was applied in pharmaceutical, urine, and water samples and recovery values in the range of 88 to 105%, attesting to the accuracy and absence of matrix interference. For urine analysis, the selective detection of NPX was attained by using sequential amperometric detection to overcome the interference of electroactive species in the sample matrix. Thus, due to the great performance, the 3D-printed CB/PLA electrode proves to be an affordable and reliable platform for clinical, pharmaceutical and environmental purposes.

Using Bismuth Vanadate/Copper Oxide Nanocomposite as Photoelectrochemical Sensor for Naproxen Determination in Sewage

AbstractConventional sewage treatment plants are not usually designed to remove emerging contaminants, and this shortcoming leads to the discharge of pharmaceuticals, among other emerging pollutants, into the environment. The present work reports the development of BiVO4/CuO‐based photoelectrochemical sensor for the determination of naproxen in sewage samples. Morphological characterizations were carried out by X‐ray diffraction and Scanning electron microscopy. The band gap energy of the nanocomposite material was calculated by Tauc plots using the data obtained from diffuse reflectance spectroscopy analysis. The sensor presented analytical signal during the photocurrent generation simultaneously with the oxidation of naproxen on the working electrode. The sensor responses were found to be proportional to the increase in naproxen concentration in the linear range of 5 nmol L−1 to 480 nmol L−1, R2=0.996, with a limit of detection of 5 nmol L−1. The presence of naproxen in sewage samples was successfully determined with recovery percentages above 95 %.

Nanomaterial-Based Carbon Paste Electrodes for Voltammetric Determination of Naproxen in Presence of Its Degradation Products.

The present work describes a novel, simple, and fast electroanalytical methodology for naproxen (NAP) determination in pharmaceutical formulations and biological fluids in the presence of its degradation products. Carbon paste electrodes (CPEs) modified with different carbon nanomaterials, namely, glassy carbon powder (GCE), multiwall carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), graphene nanosheets (Gr), and graphene oxides (GO) were tested. Comprehensive studies were performed on the electrode matrix composition including the nature of the pasting liquids, pH, carbon nanomaterials, and mode of electrode modification. Two anodic oxidation peaks were recorded at 0.890 and 1.18 V in 1 × 10−1 mol·L−1 phosphate buffer solution at pH 6. Oxidation of naproxen (NAP) is an irreversible diffusion-controlled process. Calibration plots were rectilinear in the concentration ranging from 0.067 to 1.0 µg·mL−1 with correlation coefficient 0.9979. Photodegradation of NAP resulted in disappearance of the oxidation peak at 1.18 V, allowing simultaneous determination of NAP in presence of its degradation product. The achieved high sensitivity and selectivity suggest the application of the proposed protocol for naproxen determination in pharmaceutical preparations and human blood plasma.

Sensitive voltammetric method for the determination of naproxen at the surface of carbon nanofiber/gold/polyaniline nanocomposite modified carbon ionic liquid electrode

The voltammetric determination of naproxen was carried out at the surface of 1 butyl-3-methylimidazolium hexafluorophosphate (Bmim[PF6]) carbon paste electrode (CPE) modified by carbon nano fiber (CNF)/gold nanoparticles (Au)/polyaniline (PANI). Bmim[PF6] containing a butyl-3-methylimidazolium and hexafluorophosphate anion has an ionic structure and can be utilized as an electrode modifier. It was purchased and casted on to the surface of a CNF/Au/PANI/CPE. Also, CNF/Au/PANI nanocomposite was prepared, characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) techniques and applied for CPE modification. The oxidation of naproxen was reported using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) and was performed in a blank phosphate buffer solution. Under the optimized conditions, the proposed method shows good linearity over the range from 0.050 to 20.0 nM and the detection limit is as low as 0.016 nM. The modified electrode exhibits good selectivity toward naproxen in the presence of some inorganic cations. The rendered method was successfully applied to naproxen determination in urine and pharmaceutical samples.

Kinetic and mechanistic aspects of hydroxyl radical‒mediated degradation of naproxen and reaction intermediates

Hydroxyl radical (•OH) based advanced oxidation technologies (AOTs) are effective for removing non‒steroidal anti−inflammatory drugs (NSAIDs) during water treatment. In this study, we systematically investigated the degradation kinetics of naproxen (NAP), a representative NSAID, with a combination of experimental and theoretical approaches. The second−order rate constant (k) of •OH oxidation of NAP was measured to be (4.32 ± 0.04) × 109 M−1 s−1, which was in a reasonable agreement with transition state theory calculated k value (1.08 × 109 M−1 s−1) at SMD/M05–2X/6–311++G**//M05–2X/6–31+G** level of theory. The calculated result revealed that the dominant reaction intermediate is 2‒(5‒hydroxy‒6‒methoxynaphthalen‒2‒yl)propanoic acid (HMNPA) formed via radical adduct formation pathway, in which •OH addition onto the ortho site of the methoxy−substituted benzene ring is the most favorable pathway for the NAP oxidation. We further investigated the subsequent •OH oxidation of HMNPA via a kinetic modelling technique. The k value of the reaction of HMNPA and •OH was determined to be 2.22 × 109 M−1 s−1, exhibiting a similar reactivity to the parent NAP. This is the first study on the kinetic and mechanistic aspects of NAP and its reaction intermediates. The current results are valuable in future study evaluating and extending the application of •OH based AOTs to degrade NAP and other NSAIDs of concern in water treatment plants.

Lipid Peroxidation and Cherniluminescence during Naproxen Metabolism in Rat Liver Microsomes

1. Rat liver microsomal suspension containing NADPH and MgCl2 was incubated at 37 degrees C with naproxen, a non-steroidal anti-inflammatory drug. Thiobarbituric acid reactive substances (TBA-RS), high molecular weight protein aggregates and fluorescent substances were formed in the microsomal suspension. 2. Chemiluminescence was produced from the microsomal suspension. This chemiluminescence production was well correlated to the TBA-RS formation, indicating that the chemiluminescence production was closely associated with the lipid peroxidation. 3. The addition of SKF-525A to the microsomal suspension inhibited the production of TBA-RS, chemiluminescence and 6-demethylnaproxen (6-DMN), the oxidative product of naproxen. Further, the antioxidant, alpha-tocopherol and singlet oxygen quenchers like histidine, dimethylfuran and 1,4-diazabicyclo[2,2,2]octane strikingly inhibited the productions of chemiluminescence and TBA-RS. 4. Neither naproxen nor 6-DMN caused lipid peroxidation in the absence of NADPH. Thus, lipid peroxidation and chemiluminescence during the oxidation of naproxen in liver microsomes was suggested to be provoked by reactive oxygen species and an origin of chemiluminescence was shown to be singlet oxygen.