Determination Of Ascorbic Acid Research Articles

Electrochemical syntheses and characterization of some polydyes and their application for the simultaneous determination of ascorbic acid and uric acid

Electrochemical syntheses and characterization of some polydyes and their application for the simultaneous determination of ascorbic acid and uric acid

Development of Response Surface Approach for Determination of Paracetamol, Chlorpheniramine Maleate, Caffeine and Ascorbic Acid by Green HPLC Method: A Desirability-Based Optimization.

Design of experiment is an efficient and cost-effective tool to optimize the chromatographic separation of a multicomponent mixture. The central composite design was conducted to develop and optimize a green high performance liquid chromatography (HPLC) method for simultaneous quantitation of a quaternary mixture of paracetamol, chlorpheniramine maleate, caffeine and ascorbic acid in their pharmaceutical dosage form as well as the determination of their dissolution profile. A five-level three-factor model was performed to investigate the effect of mobile phase composition, pH and flow rate on enhanced resolution and short run time. Analysis was performed using a Kinitex EVO C18 column and a mobile phase composed of methanol: 0.02M phosphate buffer pH3.3 (34:66, v/v) at 1.0mL/min using photodiode array detection. Optimum chromatographic separation was achieved in <6min with a desirability of 0.999. Linearity was achieved over a range of 1.00-300.00, 1.00-50.00, 2.00-50.00 and 2.00-100.00μg/mL for paracetamol, chlorpheniramine maleate, caffeine and ascorbic acid, respectively, with a limit of detection (<0.1μg/mL). The greenness profile was evaluated using the analytical eco-scale and Analytical GREEnness Metric Approach with values of 81 and 0.77, respectively.

Chemical composition and antioxidant properties of native Ecuadorian fruits: Rubus glabratus Kunth, Vaccinium floribundum Kunth, and Opuntia soederstromiana

The native berries of South America present promising marketing opportunities owing to their high antioxidant content, notably rich in anthocyanin and phenolic compounds. However, Ecuador's endemic fruits, primarily found in the wild, lack comprehensive data regarding their phytochemical composition and antioxidant capacity, underscoring the need for research in this area. Accordingly, this study evaluated the total phenolic, anthocyanin, flavonoid, resveratrol, ascorbic acid, citric acid, sugars, and antioxidant content of three native Ecuadorian fruits: mora de monte (Rubus glabratus Kunth), mortiño (Vaccinium floribundum Kunth), and tuna de monte (Opuntia soederstromiana). Determination of resveratrol, ascorbic acid, citric acid, and sugars was determined by HPLC analysis, and UPLC analysis was used to determine tentative metabolites with nutraceutical properties. Antioxidant capacity was assessed using cyclic voltammetry and the DPPH method; differential pulse voltammetry was used to evaluate antioxidant power. Analysis of results through UPLC-QTOF mass spectrometry indicated that R. glabratus Kunth and V. floribundum Kunth are important sources of various compounds with potential health-promoting functions in the body. The DPPH results showed the following antioxidant capacities for the three fruits: R. glabratus Kunth >O. soederstromiana >V. floribundum Kunth; this trend was consistent with the antioxidant capacity results determined using the electrochemical methods.

Ultrasonic-assisted extraction and UHPLC determination of ascorbic acid, polyphenols, and half-maximum effective concentration in Citrus medica and Ziziphus spina-christi fruits using multivariate experimental design

This study aimed to determine the concentrations of ascorbic acid and polyphenols in fruits and peels of Citrus medica and Ziziphus spina-christi grown in Ethiopia. Conditions of ultrasound-assisted extraction (UAE) and ultra-high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) were optimized, using a multivariate experimental design. The optimum conditions of UAE were 15 min extraction time at 35 ℃, with 75 % aqueous methanol as solvent, and a fruit powder-to-solvent ratio (m/v) of 1:15. Among the different drying conditions investigated, freeze-drying was found to be appropriate for analyzing ascorbic acid, polyphenols, and antioxidant potential. The overall ranges, across the fruits and peels, of ascorbic acid, total polyphenols, and antioxidant potentials (EC50) obtained were 8.7 ± 1.4–91.2 ± 2.6 mg/100 g, 253.0 ± 6.3–764.1 ± 25.8 mg GAE/100 g and 2.4 ± 0.1–26.1 ± 2.9 mg/mL, respectively. This indicates that the fruits and peels of the studied plants are advantageous as sources of ascorbic acid and polyphenols.

Electrochemical determination of ascorbic acid using palladium supported on N-doped graphene quantum dot modified electrode

To precise screening concentration of ascorbic acid (AA), a novel electrochemical sensor was prepared using palladium nanoparticles decorated on nitrogen-doped graphene quantum dot modified glassy carbon electrode (PdNPs@N-GQD/GCE). For this purpose, nitrogen doped GQD nanoparticles (N-GQD) were synthesized from a citric acid condensation reaction in the presence of ethylenediamine and subsequently modified by palladium nanoparticles (PdNPs). The electrochemical behavior of AA was investigated, in which the oxidation peak appeared at 0 V related to the AA oxidation. Considering the synergistic effect of Pd nanoparticles as an active electrocatalyst, and N-GQD as an electron transfer accelerator and electrocatalytic activity improving agent, PdNPs@N-GQD hybrid materials showed excellent activity in the direct oxidation of AA. In the optimal conditions, the voltammetric response was linear in the range from 30 to 700 nM and the detection limit was calculated to be 23 nM. The validity and the efficiency of the proposed sensor were successfully tested and confirmed by measuring AA in real samples of chewing tablets, and fruit juice.

Determination of ascorbic acid in bulk and vitamin-C tablets using manganese (III) in aqueous acidic perchlorate media

Determination of ascorbic acid in bulk and vitamin-C tablets using manganese (III) in aqueous acidic perchlorate media

Electrochemical Sensing of Vitamin C Using Graphene/Poly-Thionine Composite Film Modified Electrode

Background: Gastric irritation and kidney problems occur due to excess ascorbic acid content, whereas the lack of ascorbic acid in the human body leads to poor wound healing, muscle degeneration, and anemia. Objectives: Herein, we report the development of an electrochemical sensor for the detection of ascorbic acid using poly-thionine/ graphene (P-Th/Gr) modified glassy carbon electrode (GCE) in 0.1 M phosphate buffer solution (PBS) (pH 7.4). Electrostatically fused graphene affixed with poly-thionine was successfully illustrated for effective voltammetric sensing of ascorbic acid. Methodology: FE-SEM indicated the blended edge of a 2D graphene sheet with a deposited thin layer of polymer, which confirmed the formation of a poly-thionine/graphene composite. The cyclic voltammetry (CV) technique was utilized for the electrochemical assay of ascorbic acid (AsA, Vitamin C). Results: With the increased concentrations of AsA, the oxidation peak current of ascorbic acid increased at 0.0 V, and the overpotential showed a decrease compared to bare GCE. The effect of scan rate on cyclic voltammograms was recorded with 500 μM of ascorbic acid from 10 mV/s to 250 mV/s, which indicated that AsA oxidation is a diffusion-controlled process on poly-thionine/ graphene-modified electrode. Conclusion: It was concluded that a poly-thionine/graphene composite-based sensor could be useful for the determination of ascorbic acid in various biological samples.

Determination of ascorbic acid in biological samples using an electrochemical sensor modified with Au-Cu2O/MWCNTs nanocomposite

In this study, we developed a novel electrochemical sensor for measuring ascorbic acid (AA) or vitamin C (C6H8O6) in urine samples. The sensor was designed using a glassy carbon electrode that was modified with a nanocomposite of Au-Cu2O and MWCNTs. We investigated the characteristics of the nanocomposite using FE-SEM, TEM, XRD, and EDS. Cyclic voltammetry (CV) was used to determine the electrochemical behavior of the modified electrode and how AA is electrooxidized. Based on the electrochemical experiments, the sensor can detect trace levels of AA through voltammetry at a working potential of 0.5 vs. Ag/AgCl. We studied and modified several experimental parameters such as the supporting electrolyte, accumulation potential, solution pH, accumulation time, and amount of modifier to optimize the performance of the sensor. Furthermore, the proposed electrode exhibited a wide linear dynamic range of 1–200 μM, with a low detection limit (S/N = 3) of 0.3 μM. The use of MWCNT semiconductors and Au nanoparticles in electrode modification likely contributed to these favorable results. The outstanding properties of the nanocomposite include a large surface area, exceptional electrical conductivity, and strong electrocatalytic activity.

Polyaniline based Highly Selective Electrochemical Sensor for Ascorbic Acid Determination: Performance Studies towards Real Sample Analysis

The electrocatalytic behavior of polianiline (PAni) towards the electro-oxidation of L- ascorbic acid (L-AA) was studied by using cyclic voltammetry. PAni synthesized by oxidative polymerization method, and characterized by using high resolution-transmission electron microscopy (HR-TEM), scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM-EDAX) confirms large globular structures, X-ray diffraction (XRD) analysis revealed that PAni with amorphous nature, whereas Fourier-transform infrared spectroscopy (FTIR) of PAni shows C-N stretching, X-ray photoelectron spectra (XPS) attributes the peaks C1s, N1s and O1s. UV-visible spectra revealed PAni is conducting and its Brunauer–Emmett–Teller (BET) surface area is 343.67 m2/g demonstrates it has high surface area and good adsorption ability. The PAni electrocatalyst showed an excellent selectivity towards L-AA in presence of different inorganic and biological expedients under similar conditions. A limit of detection (LOD) and limit of quantification (LOQ) were calculated found to be 5.1 µM and 17.2 µM respectively. Furthermore, the electrocatalyst activity towards L-AA were also validated for real sample analysis like lemon juice and vitamin-C tablet by quantifying the L-AA. The exceptionally higher conductivity and good electrocatalytic performance of PAni make it a promising material for sustainable energy generation and environmental protection without relying on metals or harmful chemicals.

Physiochemical study of some perennial fruits and vegetables available in local market of Bangladesh

Fruits and vegetables are generally valued for their rich content of vitamins and minerals. The chemical composition such as moisture, ash and total vitamin C content of five vegetables (potato, pumpkin, carrot, green papaya, bitter gourd) and five fruits (mango, lemon, cucumber, pineapple, tomato) were examined methodically in this investigation. The investigation is performed by gravimetric and thermo-gravimetric methods which occurred by using oven, muffle furnace and titrating instrumentation. The result indicated that moisture content varied from 75.33% to 95.80%, ash content varied from 0.19% to 1.21% and vitamin C content varied from 9.1 mg/ml to 55.66 mg/ml in the selected samples. These outcomes conclusively hint that moisture content is highly presented in tomato, ash content is high in mango and vitamin C is high in lemon. Moisture content is used for the quality factor of some products like jams and jelly sugar crystallization and food packaging. Ash content measures the minerals in the food and minerals are very essential elements for the body. Vitamin C is the master of extraction and determination of ascorbic acid in food products and it’s a complete deficiency that results in scurvy.

Dynamically regulating transient chemiluminescence of illuminated carbon nitride for simultaneous determination of ascorbic acid and dopamine

Developing a new strategy for a chemiluminescence (CL) sensor array to identify multiple biomarkers for psychiatric disorders simultaneously is a highly challenging task. This study designed a novel and straightforward strategy for simultaneous ascorbic acid (AA) and dopamine (DA) determination based on the interesting transient CL (TCL) kinetic curve tunability phenomenon on efficient graphite carbon nitride (CN) nanosheets. Advanced photoinduction strategies were introduced to synthesize light-illuminated CN nanosheets (L-CNNSs) as sensing materials with more negative reduction potential, excellent electron-hole separation, charge transfer capabilities, and high CL activity. Notably, using L-CNNSs as a sensing material could induce strong CL of alkaline lucigenin. This newly developed CL sensor exhibited high activity, excellent selectivity, and characteristic transient response toward AA and DA. Based on this finding, we developed a direct CL sensing platform for DA and AA discrimination in the urine of patients with mental disorders. Through many experiments, we attributed the CL recognition mechanism of the L-CNNSs/lucigenin system for DA and AA to the dynamic regulation of superoxide anions (O2·−) generation in the L-CNNSs solution. The different O2·− generation rates from L-CNNSs/lucigenin/AA and L-CNNSs/lucigenin/DA were regulated to obtain ‘flash-type’ and ‘sustained-type’ TCL curves, respectively, achieving simultaneous AA and DA discrimination and detection. This study provides insights for the simultaneous identification of multiple components based on CL sensors and offers new possibilities for practical analysis of sensor arrays.

Electrochemical nanosensor based on Ag-doped TiO2 nanotubes for detecting ascorbic acid

This work describes the development of an electrochemical nanosensor for the quantitative determination of ascorbic acid (AA). The transducer and receptor system of the nanosensor is based on a silver-doped titanium oxide nanotube (Ag-TiO2NTs) electrode synthesized by a one-step electrochemical anodization method followed by an annealing treatment. The synthesis was carried out at a constant potential of 30 V for 45 min in an organic electrolyte in the presence of F- ions and the dopant. The obtained structure was then subjected to morphological and compositional analysis. In addition, its analytical response to ascorbic acid was evaluated. The analytical techniques employed included scanning electron microscopy (SEM), X-ray diffraction (DRX), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The results demonstrate the growth of a highly ordered nanotube array with average dimensions of 80 nm, 19 nm and 1660 nm for diameter, wall thickness and length, respectively, and suggest a major composition of silver-doped titanium oxide. The synthesized Ag-TiO2NTs successfully recorded electroanalytical activity for ascorbic acid, with a non-reversible, diffusion-controlled, and mostly capacitive electrochemical profile. It showed low resistance to change transfer and registered a sensitivity of 216.24μA/(mM∙cm2) and a detection limit of 11.1 μM in a linear range of 840–4000 μΜ. The sensor demonstrated repeatability and reproducibility with RSD values of 5.5% and 2.8%, respectively. In addition, it showed selectivity for AA in the presence of glucose at AA/GLU values (1:1, 1:10 and 1:100).

Biotemplated fabrication of N/O co-doped porous carbon confined spinel NiFe2O4 heterostructured mimetics for triple-mode sensing of antioxidants and ameliorating packaging properties

In this work, shrimp shell-derived magnetic NiFe2O4/N, O co-doped porous carbon nanozyme with superior oxidase (OXD)-like activity was prepared and used for colorimetric/photothermal/smartphone dual-signal triple-mode detection of antioxidants in fruits and beverages. The magnetic NiFe2O4/N, O co-doped porous carbon (MNPC) material was triumphantly fabricated using a combined in-situ surface chelation and pyrolysis method. The resultant MNPC composite exhibits a superior OXD-like activity, which can effectively oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) for yielding colorimetric/temperature dual-signal (CTDS) in absence of H2O2. This CTDS output sensor was successfully used for the determination of ascorbic acid and tannic acid. The proposed CTDS sensor with good specificity and high sensitivity can satisfy different on-site analysis requirements. Interestingly, the MNPC as a sustainable filler was further used for improving packaging properties of polyvinyl alcohol film. In short, this work offers a large-scale and cheap method to fabricate magnetic carbon-based nanozyme for monitoring antioxidants and ameliorating packaging properties.

Facile in-situ synthesis of Ti3C2Tx/TiO2 nanowires toward simultaneous determination of ascorbic acid, dopamine and uric acid

The development of electrochemical sensors with high sensitivity for the simultaneous detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA) is urgently desirable in clinical medicine. However, the challenge lies in achieving simultaneous detection due to their closely oxidation potentials. In this work, we present the synthesis of a composite material comprised of in-situ grown TiO2 nanowires (NWs) on a Ti3C2Tx substrate (Ti3C2Tx/TiO2 NWs) through a facile alkali process. By modifying a glassy carbon electrode (GCE) with Ti3C2Tx/TiO2 NWs (Ti3C2Tx/TiO2 NWs/GCE), it showed excellent electrocatalytic activity for the simultaneous detection of AA/DA/UA by regulating the surface functional groups of Ti3C2Tx. Remarkably, the Ti3C2Tx/TiO2 NWs/GCE enabled simultaneous detection of AA in the range of 300–1800 μM, DA in the range of 2–33 μM, and UA in the range of 2–33 μM. The limits of detection (LODs) for AA, DA, and UA were estimated as 6.61 μM, 0.093 μM, and 0.038 μM, respectively. The proposed Ti3C2Tx/TiO2 NWs/GCE demonstrated good stability, high selectivity, reliable reproducibility and satisfactory recovery results in real samples, making it a promising electrochemical sensor for the detection of AA, DA, and UA. This work offers a new perspective for human health monitoring, paving the way for advancements in this field.

Zirconium oxide-porous carbon derived from metal-organic frameworks as a new sensing platform: application to simultaneous voltammetric determination of ascorbic acid, dopamine and uric acid

Zirconium oxide-porous carbon derived from metal-organic frameworks as a new sensing platform: application to simultaneous voltammetric determination of ascorbic acid, dopamine and uric acid

Spectrum-resolved photoelectrochemical molecularly imprinted sensors for simultaneous determination of ascorbic acid and uric acid in a differential mode

Herein, a spectrum-resolved differential strategy was proposed to enhance further the selectivity of photoelectrochemical (PEC) sensors, demonstrated by the simultaneous determinations of ascorbic acid (AA) and uric acid (UA). Molecularly imprinted polymer (MIP) membranes for AA (MIPAA) and UA (MIPUA) were fabricated on the surface of TiO2 nanotubes via electropolymerization, using pyrrole as functional monomer, AA and UA as templates, respectively. It was shown that the increase in absorbance from AA or UA within the MIP membranes resulted in an intense decrease in the photocurrent of the PEC sensors. In the spectrum-resolved differential mode, ΔRIAA= (IAA/IAA0−IUA/IUA0)310 and ΔRIUA= (IUA0/IUA −IAA0/IAA)275 were used in the simultaneous determinations of AA and UA, respectively. Where IAA, IAA0, IUA and IUA0 are the photocurrents of MIPAA and MIPUA in sample and blank, the subscripts of 275 and 310 stand for the excitation wavelength (nm), respectively. The interference levels in the differential mode were reduced by one order of magnitude compared with the normal MIP mode. The spectrum-resolved differential PEC MIP sensors were used in the simultaneous determination of AA and UA in serum and urine samples, with the detection limits of 0.019 and 0.036 μM, respectively.

A Simple Flow Injection System for Amperometric Detection of Ascorbic Acid Using Carbon Paste/Copper Schiff Base Composite Electrode

AbstractIn this paper, a simple, sensitive, and precise flow injection system was optimized and applied to ascorbic acid determination with a carbon paste electrode modified with the Schiff base copper complex. The modified sensor showed increased sensitivity toward ascorbic acid oxidation with a decrease of oxidation potential by 200 mV. Under optimized flow parameters, working potential, gasket thickness, sample and reaction coil volumes, and flow rate, the developed flow system gave a linear response from 5 to 75 μmol/L of ascorbic acid. The calculated limit of detection was 4.5 μmol/L, calculated as 3σ/s which corresponds to the absolute value of 40 ng for the 50 μL sample coil. The precision for six consecutive injections of 5 and 75 μmol/L ascorbic acid solutions was determined as a relative standard deviation of 5.8 % and 1.5 %, respectively. The flow injection system enabled up to 120 analyses per hour. An optimized flow system was applied to the determination of ascorbic acid in dietary supplements, after simple preparation.

Development of an efficient electrochemical sensor based on MoS2 nanosheets and ionic liquid modified carbon paste electrode for determination of ascorbic acid in the presence of vitamin B6

Development of an efficient electrochemical sensor based on MoS2 nanosheets and ionic liquid modified carbon paste electrode for determination of ascorbic acid in the presence of vitamin B6

Azalea Petal-Derived Porous Carbon–Thionine Based Ratiometric Electrochemical Sensor for the Simultaneous Determination of Ascorbic Acid and Uric Acid

Azalea Petal-Derived Porous Carbon–Thionine Based Ratiometric Electrochemical Sensor for the Simultaneous Determination of Ascorbic Acid and Uric Acid

Colorimetric detection of α-glucosidase activity using Ni-CeO2 nanorods and its application to potential natural inhibitor screening

In this work, we established an exceptionally facile method for the preparation of Ni-CeO2 nanorods in a kind of deep eutectic solvents (DESs) composed of L-proline and Ce(NO3)3·6H2O. First, Ni-CeO2 nanorods were successfully prepared by adding Ni(NO3)3·6H2O to DESs. Then, we found that Ni-CeO2 nanorods prepared in DESs have more prominent oxidase-like activity than pure CeO2. The outstanding catalytic activity of Ni-CeO2 could be ascribed to its high Ce3+/Ce4+ ratio. As a proof-of-concept application, the Ni-CeO2 nanorods were successfully acted as a colorimetric platform for the sensitive determination of ascorbic acid and α-glucosidase activity, which displays excellent analytical performance. Moreover, this sensing platform was applied for screening natural α-glucosidase inhibitors, such as terpenoids from natural products. The results indicated that ursolic acid and oleanolic acid had good inhibitory rates. This strategy not only provides a new way to construct more kinds of nanomaterials from DESs, but also offers a facile and effective tool to screen the α-glucosidase natural inhibitors as potential anti-diabetic drugs.