Analytical Method For Determination Research Articles

CoWO4/Reduced Graphene Oxide Nanocomposite-Modified Screen-Printed Carbon Electrode for Enhanced Voltammetric Determination of 2,4-Dichlorophenol in Water Samples

Water pollution with phenolic compounds is a serious environmental issue that can pose a major threat to the water sources. This pollution can come from various agricultural and industrial activities. Phenolic compounds can have detrimental effects on both human health and the environment. Therefore, it is essential to develop and improve analytical methods for determination of these compounds in the water samples. In this work, the aim was to design and develop an electrochemical sensing platform for the determination of 2,4-dichlorophenol (2,4-DCP) in water samples. In this regard, a nanocomposite consisting of CoWO4 nanoparticles (NPs) anchored on reduced graphene oxide nanosheets (rGO NSs) was prepared through a facile hydrothermal method. The formation of the CoWO4/rGO nanocomposite was confirmed via different characterization techniques. Then, the prepared CoWO4/rGO nanocomposite was used to modify the surface of a screen-printed carbon electrode (SPCE) for enhanced determination of 2,4-DCP. The good electrochemical response of the modified SPCE towards the oxidation of 2,4-DCP was observed by using cyclic voltammetry (CV) due to the good properties of CoWO4 NPs and rGO NSs along with their synergistic effects. Under optimized conditions, the CoWO4/rGO/SPCE sensor demonstrated a broad linear detection range (0.001 to 100.0 µM) and low limit of detection (LOD) (0.0007 µM) for 2,4-DCP determination. Also, the sensitivity of CoWO4/rGO/SPCE for detecting 2,4-DCP was 0.3315 µA/µM. In addition, the good recoveries for determining spiked 2,4-DCP in the water samples at the surface of CoWO4/rGO/SPCE showed its potential for determination of this compound in real samples.

Equivalent spring-like system for two nonlinear springs in series: application in metastructure units design

AbstractThe paper deals with the problem of design of unit in auxetic metastructure. The unit is modeled as a two-part spring-like system where each part is with individual stiffness. To overcome the problem of analyzing of each of parts separately, the equivalent spring is suggested to be introduced. In the paper, a method for obtaining the equivalent elastic force of the unit is developed. The method is the generalization of the procedure suggested for substitution of a hard and a soft spring in series with an equivalent one. The nonlinearity of original springs is of quadratic order. As a results, it is obtained that the equivalent elastic force for two equal springs remains of the same type as of the original springs (soft or hard). For two opposite type springs in series with equal coefficients, the equivalent force is soft. The method is applicable for any hard and soft nonlinear springs or spring-like systems. Thus the hexagonal auxetic unit which contains a soft and a hard part in series is analyzed. In the paper, a new analytic method for determination of the frequency of vibration for the unit under action of a constant compression force acting along the unit axis is introduced. The method is applied for units which contain two parts: hard–hard, soft–soft, hard–linear, soft–linear and opposite. The obtained approximate vibration results are compared with numerically obtained ones and show good agreement. The advantage of the method is its simplicity as it does not require the nonlinear equation of motion to be solved.

Methods of L-Dopa Extraction by the Method of Analytical Determination for Parkinson’s Neurodegenerative Disease

Levodopa the majority of Parkinson's disease patients eventually require levodopa medication. The chemical dopamine, which is produced when levodopa is absorbed by brain nerve cells, is used for send messages from brain regions,neurons,and synaptic memberane. that regulate movement.this neurodegenerative disease can cause uncontrollable movements, shivering, and problem balancing and muscle control. Only a few plants in the Fabaceae family have substantial amounts of isolated L-dopa; the rest are either chemically synthesized or derived from natural sources.(HPLC) added with mass spectrometry else it can added with UV-visible detection. Most frequently, HPLC is utilized.

A highly accurate analytical method for determination of the vibrational frequency of N/MEMS with electrostatic and van der Waals interaction forces

A highly accurate analytical method for determination of the vibrational frequency of N/MEMS with electrostatic and van der Waals interaction forces

Ultra-rapid determination of andrographolide and dehydroandrographolide in Andrographis Herba by solid phase extraction and liquid chromatography with mass spectrometry

AbstractAn ultra-rapid analytical method for determination of andrographolide and dehydroandrographolide in Andrographis Herba (AH) was developed by liquid chromatography with mass spectrometry (LC-MS). The sample was ultrasonically extracted with 10 mL 40% (v/v) methanol, and then purified with a C18 solid phase extraction column. The LC separation was performed on a Poroshell 120 EC-C18 column (30 × 2.1 mm, 2.7 μm) and eluted with 0.5 mmol L−1 ammonium acetate aqueous solution and acetonitrile (65:35) at a flow rate of 0.7 mL min−1, and detected by mass spectrometry (MS). The LC-MS analytical time was less than 1 min. The new developed method presented a good linearity (r > 0.9900), precision and repeatability (RSD < 2.0%). The recoveries for andrographolide and dehydroandrographolide were 93.5% (RSD = 2.2%) and 97.7% (RSD = 2.4%), respectively. The developed method was successfully applied in determination of andrographolide and dehydroandrographolide in seven batches of AH samples, and the contents of analytes in all samples were complied with the relative acceptance criteria in Chinese Pharmacopeia (>0.8%). This new developed LC-MS method is an ultra-rapid assay method for AH, which will help to improve the efficiency and reduce the cost of AH sample test.

Development of analytical method for determination of 1,3-dimethylamylamine in sports nutrition and bodybuilding supplements using pH-switchable deep eutectic solvents followed by high-performance liquid chromatography-diode array detector.

In this work, an easy, safe, simple, and efficient pH-switchable deep eutectic solvents (DESs)-based liquid phase microextraction followed by high-performance liquid chromatography-diode array detector analysis was developed for the determination of 1,3-dimethylamylamine (DMAA). The switchability of the obtained DESs was investigated by changing the pH. Then the best-selected DES was characterized and the application of the selected DES in the extraction of DMAA from sports nutrition and bodybuilding supplements was investigated. The DES synthesized from l-menthol: oleic acid in a molar ratio of 1:2 had the highest efficiency in the extraction of the target compound. Under the optimum conditions, (50µL of DES, 100µL of 4mol/L KOH, 100µL of 4mol/L HCl, extraction time of 40 s and without salt addition) the calibration graph was linear in the range of 0.05-100µg/kg and limit of detection was 0.02µg/kg. The relative standard deviations including intra-day and inter-day for 10.0µg/kg of DMAA in real samples were 2.7% (n=7) and 5.3% (n=7), respectively. The enrichment factor and percentage extraction recovery of the method were 283 and 85%, respectively. The relative recoveries for DMAA in different samples were in the range of 90%-109%.

A Review on Analytical Methods for Determination of Azithromycin

Azithromycin treatment has been associated with a decrease in ventilation time and death in several viral infections. It possesses immune-modulating properties, including the capacity to inhibit cytokine production, preserve the integrity of epithelial cells, and prevent lung fibrosis. Primary hepatic metabolism is the process by which drugs are broken down into inactive metabolites that keep their biological effects. These prompted numerous studies and publications that used a variety of analytical techniques to find, evaluate, and investigate azithromycin and its metabolites. This review aims to provide an overview of the various analytical techniques—such as voltammetry, flow injection, hyphenated mass spectrometry, and chromatography—that have been published for the years 1990 to 2020 in order to determine azithromycin. While azithromycin was most commonly quantified using high-performance liquid chromatography, the study's results indicate that when compared to alternative techniques, liquid chromatography-mass spectrometry had the highest sensitivity, with a limit of detection of 0.0005 µg/mL.

Analysis of methods for determination of cast iron hardness based on assessment of measurement accuracy

Analysis of methods for determination of cast iron hardness based on assessment of measurement accuracy

Multirezidualna metoda za določanje ostankov fitofarmacevtskih sredstev v medu s plinsko kromatografijo sklopljeno s tandemsko masno spektrometrijo

In our laboratory we introduced and validated a new analytical method for determination of environmental pesticide residues in honey. The extraction was conducted using acetone, petroleum ether and dichlorometane. The determination was conducted using gas chromatography coupled with tandem mass spectrometry. Practical usage of method was analyses of 31 samples of Slovenian honey. 33 active substances (pesticides) were sought. The insecticide cypermethrin was the only active substance found in three samples. The active substances sought were not found in 90.3 % of the samples analysed. The risk assessment showed that no unacceptable risk is expected for consumers. The results were compared with those from the literature. We revealed that honey from Slovenia contained a lower portion of positive samples per active substance sought as in Italy, comparable as in Estonia and Spain, comparable to higher as in Poland and higher as in Egypt.

Implementing magnetic molecularly imprinted solid phase extraction to analytical method for determination of 2-phenethylamine in cocoa powder and chocolate by LC-MS/MS system

The main aim of this study was to design, develop, and apply magnetic molecularly imprinted polymer (MMIP) during sample pretreatment before liquid chromatography tandem mass spectrometry (LC-MS/MS) 2-phenylethylamine determination in cocoa powder and chocolate samples. The morphology and structure of MMIP, obtained from methacrylic acid (monomer) and trimethylolpropane trimethacrylate (cross-linker) were characterized using scanning electron microscopy, nitrogen sorption analyses, infra-red spectroscopy, X-ray diffraction measurements, vibrating-sample magnetometry, and thermogravimetry analyses. The analyte adsorption mechanism on MMIP was studied using computational simulation. The magnetic solid phase extraction procedure on MMIP was optimized, resulting in a relative matrix effect of 6.2 % for cocoa powder and 2.8 % for chocolate. The LC-MS/MS quantified the 2-phenethylamine in eighteen cocoa powder and chocolate samples, showing a concentration range between 2.4 and 8.7 μg g−1.

A Review On : To Develop and Validate Analytical Method for Determination of Methimazole in Bulk and Pharmaceutical Dosage Form

Hyperthyroidism is a condition characterized by increased in synthesis and secretion of thyroid hormones from thyroid gland. Methimazole is an anti-hyperthyroidism drug. It is of great importance and significance for life science. Up to now, various different methods have been applied for the determination of methimazole, such as spectrophotometry1-3, LC4, HPLC6, RP-HPLC7, HPLC-UV8, electrochemical analysis9, kinetic method10. In this paper, a new UV-Spectrophotometric method for the determination of methimazole has been established. The chemical name of Methimazole is (1-methylimidazole-2-thiol). The chemical formula of Methimazole is C4H6N2S and the molecular weight is 114.17 g/mol. The structure of Methimazole features a 5 membered imidazole ring with a methyl group at position 1st and thione group at position 2nd. Methimazole is white colour powder and has melting point 1440 C.

Sustainable analytical method for determination of bioactive compounds in solid oral formulations (capsules and tablets) containing green tea (Camellia sinensis) marketed in Brazil

This study presents the development of a sustainable analytical method using high-performance liquid chromatography (HPLC) for determination and quantification of bioactive compounds in Herbal Dietary Supplements (HDS) solid oral formulations containing green tea (Camellia sinensis). Four compounds [gallic acid, (+)-catechin, caffeine and caffeic acid] were determined in fifteen HDS samples (capsules and tablets) containing green tea marketed in Brazil. After optimizing the extraction process using factorial planning and response surface analysis, it was possible to develop the method. Methanol and acetic acid (0.25%) were components of the mobile phase, showing it as a more sustainable alternative to the use of acetonitrile. The samples evaluated demonstrated a lack of standardization in the concentrations (in mg g−1) of the chemical markers studied gallic acid (<LOD to 1.39), (+)-catechin (<LOD to 13.8), caffeine (<LOQ to 22) and caffeic acid (<LOD to 1.7). This concern has driven significant scientific research on the topic. The chromatographic method proved to be effective, sensitive and robust for qualification and quantification of the 4 chemical markers studied. This study found variations in the levels of chemical markers in HDS containing green tea sold in Brazil. Therefore, it can contribute to the regulation and quality control of these solid oral products (capsules and tablets) containing this plant.

Development and validation of analytical method for determination of elemental impurities in micafungin for injection

Elemental impurities contained in drug product create a risk for patients and potential toxic elemental impurities defined and classified in Guideline for Elemental Impurities Q3D(R1). Among the finished product dosage forms, parenteral products could be critical for elemental impurities because elemental impurities are given directly to systemic circulation. For determination of elemental impurities, one of the most frequently used methods is inductively coupled plasma–mass spectrometry (ICP–MS). In this study we aimed to develop and validate an ICP-MS method for determination of 24 elemental impurities in micafungin powder for concentrate for solution for infusion manufactured in our own facility. Results showed that correlation coefficients of calibration curves were found higher than 0.99 for all elements in determined ranges and all validation parameters were achieved successfully. With this method, all 24 elemental impurities can be tracked throughout the shelf life of the product.

Rapid screening of drugs in environmental water using metal organic framework/Ti3C2Tx composite coated blade spray-mass spectrometry

Simultaneous rapid screening of multiple drugs of abuse in environmental water facilitates effective monitoring and trend assessments. Herein, a novel porphyrin-based metal organic frameworks modified Ti3C2Tx nanosheets (Cu-TCPP/Ti3C2Tx) composite was prepared and utilized as solid-phase microextraction (SPME) coating for the simultaneous analysis of 21 drugs from water samples. The composite was embedded with matrix-compatible polyacrylonitrile binder to prepare a coated blade with thin and uniform coating layer. Ambient mass spectrometry (MS) technique was used to create a coated blade spray-MS (CBS-MS) method for the quantitative determination of drugs in water samples. High throughput and automated sample preparation were achieved with the use of a Concept 96-well plate system, enabling analysis of 21 drugs of abuse within 1 min per sample, while using only 8 µL of organic solvent for desorption and CBS-MS detection. The developed method showed favorable linearity (R2 ≥ 0.9983) in the range of 0.05 to 10 ng mL−1, low limits of detection (1.5–9.0 ng L-1), sufficient recovery (67.6–133.2%), as well as satisfactory precision (RSDs≤13.5%). This study not only delivers a novel and efficient SPME coating composite, but also demonstrates the excellent performance of a high-throughput, efficient, and green analytical method for determination of drugs in environmental water.

Choline chloride-L-lactic acid mixtures as solvents for extraction of Coumarin from cinnamon-containing foods

The determination of coumarin in generally available cinnamon-containing foods such as biscuits, cereals is important to ensure that the populations consuming these foods more frequently are not exposed to higher levels and are not at risk. This study describes the development of an analytical method for determination of coumarin in foods containing cinnamon. Solid-liquid phase extraction with conventional stirring-assisted and ultrasound-assisted extraction (UAE) procedures were used to prepare sample extracts for liquid chromatography analysis. The green solvent, a mixture of choline chloride:L-lactic acid (1:4, mol/mol)/water (50:50 v/v), as a deep eutectic solvent-like mixture, was selected as an extraction solvent. The extraction conditions were optimized by using the design of the experiment strategy obtaining parameters, temperature 47 °C, time 36 min, solvent volume 4 mL, sample amount 0.8 g, stirring speed 20 rpm for rotary stirring-assisted extraction procedure, and temperature 30 °C, time 5 min, solvent volume 3.5 mL, sample amount 0.8 g for UAE. High-performance liquid chromatography separation with a total analysis time of 12 min was performed with a stationary phase of octadecyl type and a gradient of mobile phase of methanol-1 % acetic acid. The methods were successfully validated to show the detection limit of 0.13 μg.mL−1, the linearity range of 0.4–50 µg.mL−1 (R2 = 0.999), recovery values more than 80 %, and the RSDs of less than 7 %. Rotary stirring-assisted extraction showed moderately higher recovery values than UAE, while lower RSD % was observed for UAE.

A Review of Analytical Methods for Determination of Antidiabetic and Antihypertensive Drugs in Pharmaceuticals

A Review of Analytical Methods for Determination of Antidiabetic and Antihypertensive Drugs in Pharmaceuticals

Review on analytical methods for determination of furosemide

Review on analytical methods for determination of furosemide

Analytical methods for determination of azelastine hydrochloride and fluticasone propionate in different matrices: A mini review

Analytical methods for determination of azelastine hydrochloride and fluticasone propionate in different matrices: A mini review

Development of an Analytical Method For Determination of Urine 3-Phenylpyruvic Acid Based on Liquid-Liquid Extraction and LC-MS/MS

Aim: The aim of this study is to develop a rapid, precise, specific LC MS MS method for the determination of 3-phenylpyruvic acid, which has an important place in the diagnosis of phenylketonuria, a metabolic disease resulting from Phenylalanine Hydroxylase Enzyme deficiency.&#x0D; Materials and Methods : Analytical measurements were made with Acqutiy UPLC MS MS (Waters Xevo TQD). The chromatographic separation was operated on an Acquity UPLC Phenyl column (50 mm × 2.1 mm, 1.7 μm) with gradient elutionusing 0.1% formic acid containing water and methanol as the mobile phase. Within the scope of the study, firstly, sample preparation steps were focused and dispersive liquid liquid extraction and traditional liquid extraction methods were examined. The best results were obtained in the conventional liquid liquid extraction method, in which dichloromethane was used as the extraction solvent. In addition, in this study, trans cinnamic acid was tested as an internal standard for the determination of 3-phenylpyruvic acid and passed the validation steps.&#x0D; Results : The linear range of the developed LC MS MS method was found to be between 0.009-5 M, while the detection limit was found to be 0.001 M. Intraday repeatability was below 7% for 3 levels, and interday repeatability was below 10%. In the recovery trial, which showed the accuracy of the method, the results in the urine sample for 3 levels were in the range of 97%-103%, and there was no significant ion suppression in the matrix effect trial, which showed how clean the final matrix obtained as a result of the sample preparation steps was.&#x0D; Conclusion: As a result, a fast, inexpensive LC MS MS method has been developed for 3-Phenylpyruvic acid.

Greenness assessment of analytical methods for determination of cannabinoids in oils using NEMI, Analytical Eco-Scale, AGREE and GAPI.

The cannabis plant is being increasingly researched due to its numerous therapeutic properties leading to the need for analytical techniques to assess substances present in extracts of the cannabis plant in carrier oils, such as medium chain triglycerides (MCT) oil. Awareness of the environmental impact of activities related to analysis led to the development of greenness assessment metrics. This study aimed to assess the environmental impact of analytical techniques applied in the analysis of cannabinoids in oil using Green Analytical Chemistry metrics. The first phase of the study consisted of a systematic literature review to identify high performance liquid chromatography and ultra high performance liquid chromatographic methods of analysis for cannabinoids in oil. In the second phase, the identified methods were assessed using the National Environmental Method Index (NEMI), Analytical Eco-scale, Analytical Greenness Calculator (AGREE) and Green Analytical Procedure Index (GAPI). Out of 124 identified studies, 8 were considered for the comparative analysis. The identified analytical methods consisted of high performance liquid chromatography (HPLC) using high resolution MS (n = 1), DAD (n = 2), UV (n = 1), UV and MS (n = 2) and MS/MS (n = 2) as detectors. When the analytical methods were assessed using the Analytical Eco-Scale, 7 out of 8 methods achieved a score ranging between 50 and 73, categorising them as acceptable green methods of analysis. One method achieved a total score of 80, categorising the method as an excellent green analysis. The application of Green Analytical Chemistry and respective metrics during the development of analytical methods contributes towards a reduction in the environmental footprint which results from related activities.