Determination Of Hydroxylamine Research Articles

Two Steps Non-Enzymatic Synthesis of Molnupiravir, which is Free from Mutagenic Impurity and Analytical Method Development for Estimation of Genotoxic Impurity (Hydroxylamine Hydrochloride Content) by using RP-HPLC Technique

Genotoxic impurity free Molnupiravir was synthesised by a novel and an elegant non-enzymatic method, which is simple operationally and ecologically. The genotoxic raw material, Hydroxylamine, was used in the initial stages of synthesis to get the mutagenic impurity free Molnupiravir. A new and sensitive HPLC method was developed and validated for the determination of hydroxylamine in Molnupiravir drug substance according to ICH guidelines. The HPLC method was developed and optimized on Zorbax SB C18 150×4.6mm, 3.5µm column with oven temperature maintained at 40°C. 1.0 mL of Orthophosphoric acid in 1000 mL water was selected as mobile phase in isocratic reverse phase mode. Chromatographic parameters are flow rate: 0.8 ml/min, wavelength detection: 252 nm, injection volume: 10µl and run time: 20 min. Based on the validation data; the method was found to be specific, sensitive, accurate and precise. This method can be used as a good quality control tool for quantification of hydroxylamine at the low level. The experimental data was deliberated in detail in this research paper.

Sensitive Electrochemical Sensor Modified by Hydroquinone Derivative and Magnesium Oxide Nanoparticles for Simultaneous Determination of Hydroxylamine and Phenol

Sensitive Electrochemical Sensor Modified by Hydroquinone Derivative and Magnesium Oxide Nanoparticles for Simultaneous Determination of Hydroxylamine and Phenol

Sensitive Amperometric Detection of Hydroxylamine at Electropolymerized Curcumin Film Coated Pencil Graphite Electrode

AbstractIn this study, a sensitive electrochemical method was developed for the determination of hydroxylamine (H−A) using a curcumin‐modified pencil graphite electrode prepared with the electropolymerization of curcumin (PolyCurc‐PGE). The PolyCurc‐PGE showed a remarkable electrocatalytic response for H−A oxidation compared with bare PGE. Amperometric and cyclic voltammetric measurements were performed based on the electrocatalytic oxidation of H−A at PolyCurc‐PGE. Some parameters, such as monomer concentration, pH, and cycle number during electropolymerization, were optimized to obtain the best electrochemical response of the modified electrode towards H−A. Results show that the PolyCurc‐PGE gives a linear response towards H−A oxidation in the range from 0.50 μM to 500 μM (R2=0.9984). In addition, the sensitivity and detection limit (LOD) of PolyCurc‐PGE were found to be 5432 μA mM−1 cm2 and 0.15 μM H−A, respectively. The developed amperometric method was successfully applied to determine H−A in pharmaceutical and water samples, and acceptable results were obtained with high accuracy and precision.

A simple, rapid and sensitive analytical method for the determination of hydroxylamine in water samples using modified glassy carbon electrode

A simple, rapid and sensitive analytical method for the determination of hydroxylamine in water samples using modified glassy carbon electrode

Electroanalytical overview: the sensing of hydroxylamine.

One of the principal raw ingredients used in the manufacturing of pharmaceuticals, nuclear fuel, and semiconductors is hydroxylamine, a mutagenic and carcinogenic substance, ranking high on the list of environmental contaminants. Electrochemical methods for monitoring hydroxylamine have the advantage of being portable, quick, affordable, simple, sensitive, and selective enough to maintain adequate constraints in contrast with conventional yet laboratory based quantification methods. This review outlines the most recent advancements in electroanalysis directed toward the sensing of hydroxylamine. Potential future advancements in this field are also offered, along with a discussion of method validation and the use of such devices in real samples for the determination of hydroxylamine.

Sensitive determination of hydroxylamine by using modified electrode by La2O3–Co3O4 nanocomposite and ionic liquid

In the present work, an efficient, fast and sensitive method for the determination of hydroxylamine (HyA) has been developed based on carbon paste electrode (CPE) modified with La2O3/Co3O4 nanocomposite and ionic liquid (LaCo/IL/CPE). The developed method was assessed using cyclic voltammetry, chronoamperometry and differential pulse voltammetry (DPV) methods. The LaCo/IL/CPE sensor showed good response ability and good electrocatalytic activity for HyA. The results showed that, electrochemical oxidation signal of HyA at the surface of LaCo/IL/CPE was 4.8 times the signal at the surface of LaCo/CPE. Also, potential of peak (Ep) of HyA at the surface of LaCo/IL/CPE was 700 mV while at the bare CPE, HyA was not oxidized until the potential reached +1200 mV. The obtained results showed that the oxidation process of HyA at the LaCo/IL/CPE was controlled by diffusion and the average diffusion coefficient for HyA, 2.8 × 10−6 cm2/s was obtained. The experimental conditions such as pH of solution, scan rate and instrumental parameters for DPV were assessed and optimized for electrochemical determination of HyA. Under optimum conditions, a linear response for HyA in the concentration range 0.06–240.0 μM was found, with a detection limit of 3.0 nM. In the final, HyA in different water samples was detected by the standard addition procedure.

Electrochemical sensor for determination of hydroxylamine using functionalized Fe3O4 nanoparticles and graphene oxide modified screen-printed electrode

A simple strategy for determination of hydroxylamine based on Fe3O4 nanoparticles function­nalized by [2-(4-((3-(trimethoxysilyl)propylthio)methyl)1-H1,2,3-triazol-1-yl)acetic­acid] (FNPs) and graphene oxide (GO) modified screen-printed electrode (SPE), denoted as (Fe3O4 FNPs/GO/SPE), is reported. The electrochemical behavior of hydroxylamine was investigated at Fe3O4FNPs/GO/SPE by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chro­noamperometry (CHA) techniques in phosphate buffer solution (pH 7.0). Fe3O4 FNPs/GO/SPE as a novel electrochemical sensor exhibited catalytic activity toward the oxidation of hydroxyl­ami­ne. The potential of hydroxylamine oxidation was shifted to more negative potentials, and its oxidation peak current increased on the modified electrode, also indicating that under these conditions, the electrochemical process is irreversible. The electrocatalytic current of hydroxyl­amine showed a good relationship in the concentration range of 0.05–700.0 μM, with a detection limit of 10.0 nM. The proposed electrode was applied for the determination of hydroxyl­amine in water samples, too.

Determination of hydroxylamine genotoxic impurity by derivatization in penicillamine drug substance by GCHS-MS

The aim of the present research is to develop and validate highly sensitive and selective method for the quantitate determination of hydroxylamine by derivatization with acetone in presence of pyridine as a base in penicillamine drug substance by using hyphenated technique. Hydroxylamine was determined by GCHS-MS method using Gs BP-624, 30 mts × 0.32 mm × 1.8 µm column. Temperature program was set by maintaining 60 °C for 3 min, and then increased by 40 °C per minute to 200 °C and hold for 11.5 min. Methanol and acetonitrile was used as diluents. Injector temperature was 250 °C. Split ratio is 1:5. Head space oven, sample line and transfer line temperatures are 100 °C, 150 °C and 170 °C respectively. Validation of the method was performed as per standard guideline “International Conference on Harmonization” (ICH) guideline Q2(R1). This developed GCHS-MS method is able to quantitate 0.1 ppm of hydroxylamine. Under these GCHS-MS conditions hydroxylamine was quantified by selective reaction monitoring m/z of 73 as its acetone oxime derivative at ppm level. The developed GCHS-MS method was validated and resulting to show the developed method is specific, sensitive, linear, accurate and precise. Hence the GCHS-MS method is well suited for the quantification of hydroxylamine genotoxic impurity as its acetone oxime derivative in penicillamine drug substance.

Electrochemical determination of hydroxylamine through MOWS2 nano-composite modified electrode

ABSTRACT Hydro-thermal synthesised MOWS2 nano-composite has been specified and employed to the modify a screen-printed electrode (SPE) in electro-catalytic voltammetric detection of hydroxylamine. Sensor of MOWS2 nano-composite has been followed by acceptable function to detect hydroxylamine with a linear range within 0.7–400.0 µM, and a limit of detection (LOD) of 0.2 µM. Results indicated that MOWS2 nano-composite enjoy high potentials to be used in electrochemical sensing. Moreover, this modified electrode has the benefits of a significant linear association, higher sensitivity and small determination limit, acceptable anti-interference capability and very high stability, resulting in widespread uses in detecting real samples.

An innovative sensor for hydroxylamine determination: Using molybdenum hybrid zeolitic imidazolate framework–conducting polymer composite as electrocatalyst

A novel composite material, hybrid zeolitic imidazolate framework (HZIF)–conducting poly(3,4-ethylenedioxythiophene) (PEDOT) has been fabricated on carbon cloth electrode (CCE) by microwave-assisted crystallization, followed by drop-coating and vapor deposition procedures. Specifically, the HZIF inserted by molybdenum (HZIF-Mo) is entitled to intrinsic catalytic activity towards amine molecules, which is firstly integrated with the conductive and catalytic PEDOT as an enhanced electrochemical sensor for hydroxylamine. Detection is performed by amperometric method, and the composite sensor (HZIF-Mo/PEDOT/CCE) shows a low detection limit of 0.04 μM (S/N = 3) in the linear range of 0.1–692.2 μM, along with superior anti-interference ability, reproducibility (RSD = 4.43%) and outstanding performance in real samples. As noticed, the hydroxylamine catalytic process combines the advantages of the alkaline-stable HZIF-Mo containing ample catalytic sites and high surface area and the mesoporous PEDOT reining in outstanding conductivity and redox capability, thereby imparting amplified electrochemical signals. This work undertakes an opening to expand MOF-based composites for versatile sensing applications.

Electrochemical determination of hydroxylamine in water samples using modified screen-printed electrode with TiO2/GO

ABSTRACT The electrochemical behaviour of hydroxylamine at a modified screen-printed electrode with TiO2/graphene oxide (GO/TiO2/SPE) was investigated by cyclic and differential pulse voltammetry. EDS, SEM and XRD methods were implemented to characterise the nanocomposite. The hydroxylamine diffusion coefficient (D) was predicted via chronoamperometry. Moreover, the detection limit, current sensitivity and linear range for hydroxylamine were assessed via differential pulse voltammetry (DPV). The linear range and detection limit were 0.1–300 and 0.065 µM, respectively. Additionally, the sensor exhibited exceptional stability, reproducibility, selectivity and sensitivity traits. The recommended electrode was implemented to determine hydroxylamine within water specimens entailing satisfactory results.

A novel electrochemical sensor based on 2D CuTCPP nanosheets and platelet ordered mesoporous carbon composites for hydroxylamine and chlorogenic acid

In this work, porphyrin-based 2D MOF CuTCPP/platelet ordered mesoporous carbon (pOMC) composites were successfully synthesized by conventional solvothermal reaction. The introduction of pOMC increases conductivity of CuTCPP/pOMC composites, weakens accumulation of the CuTCPP layers, and exposes active sites of CuTCPP. CuTCPP/pOMC composites show high electro-catalytic activity to the oxidation of hydroxylamine and the redox of chlorogenic acid. An electrochemical sensor based on CuTCPP/pOMC was constructed for quantitative determination of hydroxylamine and chlorogenic acid, and relevant mechanisms were discussed. Under optimized conditions, the fabricated sensor displays two wide linear responses in the ranges of 5.8–733.8 μM and 733.8–2933.8 μM for hydroxylamine, with a rapid response time about 1 s. For chlorogenic acid, the sensor presents linear responses in the ranges of 0.1–2 μM and 2–15 μM, with a high sensitivity of 10.18 μA/μM. The sensor was used to detect hydroxylamine and chlorogenic acid in real samples, and satisfactory results were obtained. The synthesis of CuTCPP/pOMC composites provides new strategy for designing electrochemical sensors based on 2D MOFs.

CuCo2O4 nanobricks as electrode for enhanced electrochemical determination of hydroxylamine

In this scientific work, a precipitation method is followed for the synthesis of copper oxide (CuO), cobalt oxide (Co3O4) and copper cobaltite (CuCo2O4) and the viability of using these materials as electrode modifiers has been studied. A sensitive electrochemical sensor for the determination of hydroxylamine has been introduced. The morphology and physical properties of the as synthesized materials were characterized with several characterization tools. It is found that the morphology and size of CuO, Co3O4 and CuCo2O4 are nanoflakes (300–350 nm), nanoplatelet (75–100 nm) and nanobricks (20–45 nm), respectively. In addition, CuO, Co3O4 and CuCo2O4 oxidize hydroxylamine at 0.57 V, 0.53 V and 0.44 V, respectively. Electrocatalytic oxidation current of hydroxylamine was proportional to the concentration of hydroxylamine in the range 0.075 to 8.25 mM. Also, under optimized condition, limit of detection and sensitivity in the DPV measurement are 0.65 μM ± 0.05 μM and 13.1 μA cm−2 mM−1, respectively. Hence, the proposed sensor is highly sensitive, selective, simple, precise and stable for hydroxylamine detection in the real water samples.

Screen-Printed Electrode Modified with La3+-Doped Co3O4 Nanocubes for Electrochemical Determination of Hydroxylamine

This study represents an electrochemical sensor to determine the hydroxylamine through voltammetry methods based on a screen printed electrode (SPE) modified with La3+-doped Co3O4 nanocubes. The La3+-doped Co3O4 nano-composite was prepared through an easy chemical reduction technique. The modified SPE presented good electrocatalytic performance toward hydroxylamine oxidation. The limit of detection (LOD) (S/N = 3) and sensitivity were obtained 0.08 μM and 0.037 μA/μM, respectively. The sensor was used for detecting hydroxylamine in (spiked) water samples.

A High-Performance Liquid Chromatography Method for Determination of Genotoxic Impurity Hydroxylamine in Drug Substances.

Hydroxylamine (NH2OH) is widely used in pharmaceutical intermediates and final drug substances synthesis. Since hydroxylamine is a well-known genotoxic impurity compound that needs to be controlled down to ppm level in pharmaceutical compounds. It is very difficult to detect using conventional analytical techniques due to its physical-chemical properties like the lack of chromophore, low molecular weight, the absence of carbon atom and high polarity. In addition to that, the analysis of the pharmaceutical samples encounters considerable obstruction from matrix components that greatly overshadow the response of hydroxylamine. This report describes a simple, selective and sensitive high-performance liquid chromatography (HPLC)-UV derivatization method for the determination of hydroxylamine in drug substances. The HPLC method was detected up to 0.01 ppm of hydroxylamine with S/N > 3.0 and quantified up to 0.03 ppm of hydroxylamine with S/N ratio > 10.0. This validated method can be applied as a generic method to detect the hydroxylamine for pharmaceutical process control and drug substance release.

Tubular-structured polypyrrole electrodes decorated with gold nanoparticles for electrochemical sensing

The electrosynthesis and characterisation of polypyrrole(PPy) films with a micro-tubular structure decorated with gold nanoparticles is described. The PPy films were characterised by means of voltammetric and electrochemical impedance spectroscopy measurements. The tubular structure of the PPy films were obtained under potentiostatic conditions in freshly prepared sodium salicylate solutions. Voltammetric response of the PPy films shows that its behavior turns more reversible as the electropolymerization charge of the film increases. SEM images show the appearance of the tubular structure for an electrodeposition time higher than 2 min. The tubular-structured PPy film showed an rms of ca. 600 nm as determined from AFM imaging. These PPy films were subsequently decorated with gold nanoparticles obtained by a double step potentiostatic electrodeposition routine that allowed fine control of deposit characteristics. Analysis of deposits was performed by means of SEM and AFM nanoscopy. Statistical analysis of particles size distribution show that the maximum value appeared for 60 nm, but a significant amount of particles between 100–200 nm were also observed. The sensing capability of these composite electrodes was tested for the determination of hydroxylamine, nitrite and their mixture in solutions of different pH. Results showed a successful route of synthesis of a nanocomposite electrode with promising applications in electrochemical sensing.

Spectrophotometric determination of hydroxylamine in biological wastewater treatment processes

Hydroxylamine, a very important intermediate in nitrification, has a direct relationship with the production of nitrous oxide in biological wastewater treatment processes. The spectrophotometric method taking ferric ammonium sulfate and 1, 10-phenanthroline as the oxidant and the chromogenic agent, respectively, was used to determine the concentration of hydroxylamine in biological wastewater treatment processes. The impacts of nitrite, nitrate, orthophosphate, calcium ion and trace elements on the method were examined. The results indicated that the spectrophotometric method can be used for the determination of hydroxylamine in biological wastewater treatment processes. The correlation was significant in the range of 0.02–1.00 mg N/L (y = 1.5078x − 0.0132, R 2 = 0.9991), and the range varied to 0.05–1.00 mg N/L when nitrite and orthophosphate presented. Nitrate, calcium ion and trace elements did not interfere with the determination of hydroxylamine nitrogen. When the concentrations of nitrite nitrogen in the samples were lower than 15.00 mg/L, nitrite had a minor interference on the method. The impacts of orthophosphate on the method were complex. When the concentrations of hydroxylamine nitrogen were higher than 0.10 mg/L, the interference of orthophosphate on the method can be ignored. However, when the concentrations of hydroxylamine nitrogen in the samples were lower than 0.10 mg/L, orthophosphate had significant impacts on the determination, and a numerical method proposed can eliminate the interference of orthophosphate. The spectrophotometric method can determine the concentration of hydroxylamine in biological wastewater treatment processes quickly and conveniently and was helpful to understand the function of NH2OH in N2O production in biological wastewater treatment processes.

Preparation of cobalt-RuO2 nanocomposite modified electrode for highly sensitive and selective determination of hydroxylamine

Herein, we report the facile synthesis of cobalt and cobalt-RuO2 nanocomposite modified electrode using electrodeposition method and utilized as an electro catalyst for electro oxidation of hydroxylamine. The surface morphology and the chemical composition of cobalt and cobalt-RuO2 nanocomposite were examined using FESEM, TEM, EDAX and XPS analysis. FESEM images inferred that the cobalt Nano flakes are uniformly deposited on the mild steel substrate in which the ruthenium oxide nanoparticles are randomly incorporated. EDAX analysis also confirmed the presence of cobalt, ruthenium and oxides in the electrodeposits. The predominant orientation and the crystal structure were obtained from XRD patterns. The crystal growth is preferably in (100) plane corresponding to hexagonal closed packed structure of cobalt and the reflections of RuO2 particles are at 2θ=28.00. The electro oxidation of hydroxylamine at pure cobalt and cobalt-RuO2 nanocomposite electrode was investigated with cyclic voltammetry (CV). The onset potential of hydroxylamine oxidation on cobalt-RuO2 electrode starts at −0.09V which is comparatively lower than pure cobalt. In addition to that, upon increasing the hydroxylamine concentration, the anodic oxidation peak gets increased with the decrease in the catholic reduction peak suggesting that the proposed material had a good electro catalytic activity for the electro oxidation of hydroxylamine.

Determination of hydroxylamine using a carbon paste electrode modified with graphene oxide nano sheets

A carbon paste electrode that was chemically modified with 3-(4'-amino-3'-hydroxy-biphenyl-4-yl)-acrylic acid (3,4-AA) was used as a selective electrochemical sensor for the detection of hydroxylamine. Cyclic voltammetry (CV), choronoamperometry (CHA) and square wave voltammetry (SWV) were used to investigate oxidation of hydroxylamine in aqueous solution. Under optimized concentration the electrocatalytic oxidation current peak for hydroxylamine increased linearly with concentration in the range of 0.025–10.0 μM. The detection limits for hydroxylamine was 0.012 μM. Finally, the modified electrode was applied to detection hydroxylamine in water samples.

An electrochemical nanosensor for simultaneous determination of hydroxylamine and nitrite using oxadiazole self-assembled on silver nanoparticle-modified glassy carbon electrode

Environmental pollutions are causing serious health problems for human, and their quantification is still a big challenge. For determination of hydroxylamine and nitrite as two important environmental pollutants, a novel and highly sensitive electrochemical nanosensor has been developed for the simultaneous determination of hydroxylamine and nitrite in the presence of nine interference moieties using oxadiazole self-assembled on silver nanoparticle-modified glassy carbon electrode (OAgNPs-GCE). The charge transfer coefficient, α, and the charge transfer rate constant, k s, of oxadiazole adsorbed on AgNPs were calculated. The OAgNPs-GCE displayed excellent electrochemical catalytic activities toward the oxidation of hydroxylamine. The detection limit of 0.10 μM and two linear calibration ranges of 0.45–69.4 and 69.4–833.3 μM are obtained for hydroxylamine determination at OAgNPs-GCE surface using a differential pulse voltammetric method. The investigated method showed good stability, reproducibility, and repeatability and high recovery in real samples. Moreover, this modified electrode is found quite effective in simultaneous determination of hydroxylamine and nitrite in the presence of nine moieties. OAgNPs-GCE has been applied to the determination of hydroxylamine and nitrite at water samples with acceptable results.