Precise Analytical Method Research Articles

A NOVEL SPECTROPHOTOMETRIC METHOD FOR THE ESTIMATION OF RANOLAZINE IN BULK DRUG AND IT’S FORMULATION

The simple, rapid, precise, accurate, robust and economical analytical method has been developed for estimation of Ranolazine in bulk and pharmaceutical dosage form. This study describes the validation of an UV Spectrophotometric method for quantitative determination of Ranolazine in pharmaceutical dosage form using acetate buffer (pH 4.4) as solvent. The maximum absorbance was found at 272 nm. The Linearity was found to be in range of 5 to 40µg/ml. The %RSD for Intraday and Interday precision studies was found to be 0.793 and 0.793 respectively. The % assay was found to be 99.6%±0.05. The average % recovery of ranoalazine was found to be in between 98.5-101.7%. LOD and LOQ was found to be 0.58 µg/ml and 1.75 µg/ml respectively. The results suggest that this method can be employed for routine analysis of Ranolazine in bulk and commercial pharmaceutical formulations. KEY WORDS: Ranolazine, UV Spectrophotometric Method, Method Development and Method Validation.

Measurement analysis of three phase intelligent electricity meter based on nonlinear load

In order to improve the accuracy of non-linear load measurement in three-phase smart meters, the author proposes a measurement analysis of three-phase smart meters based on non-linear loads. The author analyzed the nonlinearity of most differential amplifiers in metering chips, theoretically analyzed the reasons for low metering accuracy under non-linear loads, and analyzed and designed the reasons for phase errors in electric energy meters. The results indicate that: At 5 %, 20 %, 100 %, and 120 % of the rated current, the phase error limits of the current transformer are ±15 ', ±8', ±5 ', and ±5', respectively. At 5 % of the rated current, the phase error generated by the transformer reaches 100 % of the rated current and 3 times that of 120 %. This is also the reason for the large error in measuring small current signals in electric energy meters. ConclusionThe author provides a precise analysis and design method for nonlinear load measurement of three-phase smart meters to improve the performance of measurement chips and improve the accuracy of nonlinear load measurement.

Seismic noise in South China Sea: High-quality time-frequency analysis from 0.01 to 125 Hz.

An efficient and precise time-frequency analysis method for real-time ocean bottom seismometer (RTOBS) data in the South China Sea (SCS) is presented. Overcoming the limitations of conventional methods, the method involves temporal segmentation, unique frequency octaves, and Fourier transforms to generate power spectral density (PSD) and probability density function profiles. The method demonstrates superior precision, computational efficiency, and full-bandwidth (0 to Nyquist) capability compared to traditional techniques, as validated through theoretical and empirical evaluations. Applied to SCS RTOBS data, it unveils temporal PSD variations, shedding light on underwater noise sources like earthquakes, offshore blasting, ship-induced disturbances, and tidal effects. Establishing background noise levels in the SCS supports noise source categorization and ocean environment monitoring. Furthermore, comparing onshore and offshore seismic stations advances interdisciplinary research, fostering a comprehensive understanding of acoustics and seismology in the region.

Analysis of unsaturated alginate oligosaccharides using high-performance anion exchange chromatography coupled with mass spectrometry.

Alginate is a commercially important polysaccharide composed of mannuronic acid and its C5 differential isomer guluronic acid. Comprehensive research on alginate and alginate lyases requires efficient and precise analytical methods for alginate oligosaccharides. In this research, high-performance anion exchange chromatography (HPAEC) in parallel with pulsed amperometric detection (PAD) and mass spectrometry (MS) was applied to the analysis of oligosaccharides obtained by alginate lyase. By optimizing the chromatographic conditions including mobile phase concentration, flow rate, and elution gradient, the analysis of a single sample could be completed in 30 min. Seven unsaturated alginate oligosaccharides were separated and identified through their analysis time observed with PAD, including all structurally different unsaturated disaccharides and trisaccharides. The quantitative analysis of seven oligosaccharides was performed based on the quantitative capability of PAD. The method exhibited adequate linearity and precision parameters. All the calibration curves showed good linearity at least in the concentration range of 0.002 to 0.1 mg/mL. The HPAEC-PAD/MS method provides a general and efficient online method to analyze alginate oligosaccharides.

Delineating the Ultra-Low Misorientation between the Dislocation Cellular Structures in Additively Manufactured 316L Stainless Steel.

Sub-micro dislocation cellular structures formed during rapid solidification break the strength-ductility trade-off in laser powder bed fusion (LPBF)-processed 316L stainless steel through high-density dislocations and segregated elements or precipitates at the cellular boundaries. The high-density dislocation entangled at the cellular boundary accommodates solidification strains among the cellular structures and cooling stresses through elastoplastic deformation. Columnar grains with cellular structures typically form along the direction of thermal flux. However, the ultra-low misorientations between the adjacent cellular structures and their interactions with the cellular boundary formation remain unclear. In this study, we revealed the ultra-low misorientations between the cellular structures in LPBF-processed 316L stainless steel using conventional electron backscatter diffraction (EBSD), transmission Kikuchi diffraction (TKD), and transmission electron microscopy (TEM). The conventional EBSD and TKD analysis results could provide misorientation angles smaller than 2°, while the resolution mainly depends on the specimen quality and scanning step size, and so on. A TEM technique with higher spatial resolution provides accurate information between adjacent dislocation cells with misorientation angles smaller than 1°. This study presents evidence that the TEM method is the better and more precise analytical method for the misorientation measurement of the cellular structures and provides insights into measuring the small misorientation angles between adjacent dislocation cells and nanograins in nanostructured metals and alloys with ultrafine-grained microstructures.

The critical thinking research trend in Indonesia’s language education journals

In the 21st century, education aims to develop research writing skills for critical thinking, emphasizing creative, collaborative, and communicative thinking skills in all programs. The study aims to gather information about a variety of studies discussing critical thinking skills in Indonesia using content analysis in many scientific language education journals published in Indonesia. This study used content analysis. Data were obtained by collecting papers that had been published in language education publications across Indonesia from 2016 to 2023, reading carefully, classifying based on the research instrument, and data was analyzed using classical content analysis technique. The results of this study, there have been more publications over the last three years that highlight critical thinking abilities. The majority of the research design used in those papers was quantitative. Furthermore, the most targeted subjects and materials were "language acquisition" and senior high school students in their tenth grade. The most widely used data analysis technique and instrument were the t-test and the test. The study suggests future studies to enhance critical thinking skills by expanding research writing options, selecting appropriate data collection instruments, validating findings, and using precise data analysis methods.

Bending creep behaviour of various polymer films analysed by surface strain measurement.

Understanding the temporal bending deformation of polymer films is key to designing mechanically durable flexible electronic devices. However, such creep behaviour under persistent bending remains unclear due to a lack of precise and accurate bending strain analysis methods. Herein, we quantitatively analysed the bending creep behaviour of various polymeric films using our developed strain measurement method that can precisely measure surface strain from optical diffraction. The surface strain measurement reveals that bending creep deformation differs depending on the polymer structure. The four-element Burgers model was employed to model the temporal strain increase on the bending surface successfully. By fitting the four-element model to the time course of the measured surface strain, we found that each polymer film has a different threshold surface strain for the appearance of bending creep deformation. Such disparity in the bending creep behaviour can be explained by the difference in strain energy density between the polymer films and their elastic model; polymer films with a small strain energy density difference show small bending creep deformation. The results obtained in this study contribute to the elucidation of the bending creep behaviour of polymer films and the development of flexible electronic devices operated under persistent bending.

THE DEVELOPMENT AND VALIDATION OF ANALYTICAL METHOD FOR EVALUATING GALLIC ACID IN ETHYL ACETATE FRACTION (EAF) OF SNEDDS FORMULATION: QUANTITATIVE ANALYSIS WITH IN VITRO ASSAY

Objective: This study aimed to develop a simple, accurate, precise, sensitive, robust, and stable analytical method for the evaluation of gallic acid in Self-Nanoemulsifying Drug Delivery System (SNEDDS) incorporating ethyl acetate fraction (EAF) of Melastoma malabathricum leaves in combination with Gentamicin. Methods: Validation process followed ICH guidelines and applied a reverse phase HPLC method with a mobile phase of acetonitrile-phosphoric buffer at pH 3.03 (20:80 v/v). The stationary phase consisted of a VP-ODS shim-pack C-18 column (250x4.6 mm) with a flow rate of 0.2 ml/min and detection at 263 nm using an Ultraviolet detector. Additionally, antioxidant activity was assessed through the DPPH and FRAP methods, and SPF value was determined with a UV/Vis spectrophotometer in the 290-390 nm wavelength range. Results: The results showed that the retention time of quercetin was 16.648 min with a tailing factor of 1.623. The regression equation (y=224689x-989000) had a concentration range of 10-55 µg/ml and a correlation value of 0.9920. Limit of Detection (LOD) and Limit of Quantification (LOQ) were found to be 2.394±0.086 and 7.254±0.260 µg/ml, respectively. Method accuracy, determined by recovery values at concentrations of 50%, 100%, and 150%, ranged from 91.18% to 109.49%. Repeatability inter-day variations were expressed as %RSD values of 1.027-1.963% for AUC and 0.150-0.145 for RT. Moreover, the applied method showed stability within a temperature range of 14 °C–35 °C. Analysis showed gallic acid content of 1.773±0.049 mg/g in SNEDDS EAF formulation. Antioxidant activity measured through the DPPH and FRAP methods yielded IC50 values of 4.167±0.552 µg/ml and 20.253±0.619 µg/ml, respectively, while SPF value at SNEDDS concentration of 150 µg/ml was 36.993±0.183. Conclusion: This study successfully developed a precise, accurate, specific, and stable method for quantifying gallic acid levels in SNEDDS EAF of Melastoma malabathricum leaves in combination with Gentamicin. Therefore, SNEDDS EAF formulation exhibited an effective wound-healing potential, supported by a robust quality control process.

Analytical determination of ethylenediamine impurity in tripelennamine hydrochloride by gas chromatography-mass spectrometry using phthalaldehyde as the derivatizing agent.

In the pharmaceutical industry, effective risk management and control strategies for potential genotoxic impurities are of paramount importance. The current study utilized GC-MS to evaluate a precise, linear, and accurate analytical method for quantifying ethylenediamine present in tripelennamine hydrochloride using phthalaldehyde as a derivatizing agent. When phthalaldehyde is sonicated for 10 min at room temperature, it reacts with ethylenediamine to form (1z,5z)-3,4-dihydrobenzo[f][1,4]diazocine. This approach minimizes matrix interference issues and resolves sample preparation difficulties encountered during ethylenediamine identification in GC-MS. In this method, helium serves as the carrier gas, while methanol acts as the diluent. The stationary phase consists of a DB-5MS column (30 m × 0.25 mm × 0.25 μm) with a flow rate of 1.5 mL/min. The retention time of (1z,5z)-3,4-dihydrobenzo[f][1,4]diazocine was determined to be 6.215 min. The method validation demonstrated limits of detection and quantification for (1z,5z)-3,4-dihydrobenzo[f][1,4]diazocine at 0.4 and 1.0 ppm, respectively, with a linearity range spanning from 1 to 30 ppm concentration with respect to the specification level. System suitability, precision, linearity, and accuracy of the current method were assessed in accordance with guidelines, yielding results deemed suitable for the intended use.

An efficient and precise stability analysis method for milling process

An efficient and precise stability analysis method for milling process

Molecular Interactions Leading to Advancements in the Techniques for COVID-19 Detection: A Review.

Since 2019 the world has been in a combat with the highly contagious disease COVID-19 which is caused by the rapid transmission of the SARS-CoV-2 virus (severe acute respiratory syndrome coronavirus 2). Detection of this disease in an early stage helps to control its spread and management. To combat this epidemic with one-time effective medication, improved quick analytical procedures must be developed and validated. The requirement for accurate and precise analytical methods for the diagnosis of the virus and antibodies in infected patients has been a matter of concern. The global impact of this virus has motivated scientists and researchers to investigate and develop various analytical diagnostic techniques. This review includes the study of standard methods which are reliable and accredited for the analytical recognition of the said virus. For early detection of SARS-CoV-2 RNA, RT-PCR (Real-time reverse transcriptase-polymerase chain reaction) is an accurate method among other methods and, thus, considered as the "gold standard" technique. Here, we outline the most extensively used analytical methods for diagnosing COVID-19, along with a brief description of each technique and its analytical aspects/perspective.

A Validated RP-HPLC Method for Simultaneous Quantification of Abacavir and Zidovudine and their Impurities in Combined Dosage Forms

Develop a simple, accurate, and precise method for simultaneous analysis of Abacavir and Zidovudine, along with their related impurities, in combined pharmaceutical dosage forms. A reverse- phase high-performance liquid chromatography (RP-HPLC) method was developed using an LC-20 AT C18 column and a Water: Methanol (80:20) mobile phase. Detection was carried out at 240 nm. The method successfully separated Abacavir, Zidovudine, and their respective impurities with distinct retention times. Validation demonstrated good linearity, accuracy, and precision for both drugs and their impurities. Limits of detection (LOD) and quantification (LOQ) were determined and found to be suitable for analyzing impurities in commercial dosage forms. The developed RP-HPLC method offers a simple, accurate, and reliable tool for simultaneous quantification of Abacavir, Zidovudine, and their impurities in combined dosage forms, thereby contributing to quality control and ensuring drug safety. Keywords Abacavir, Zidovudine, Related Substance RP-HPLC Method, ICH Q2 (R1) guidelines

An overview of automated flow systems for total and isotopic analysis of strontium and yttrium in samples of environmental interest

Due to the different uses of radioactivity during the last decades, there has been an increase in the concentration of natural and artificial radionuclides in the environment. This, along with some accidents with a high affect public opinion (for example, Chernobyl and Fukushima), have led to the growth and establishment of environmental radioactivity monitoring programs. Currently, trends in legislation and research are focused on the development of accurate, precise, reliable and fast analytical methods with low limits of detection (LOD) for radionuclides determination, such as strontium and yttrium, in environmental samples. In this paper, two comprehensive reviews and four automated analytical systems for total and isotopic determination of yttrium and strontium are presented. The developed methods have been applied in the analysis of environmental samples with low concentrations of these analytes. These methodologies have been automated by exploiting flow analysis techniques, such as multi-syringe flow injection analysis (MSFIA), Sequential injection analysis (SIA) and laboratory-on-valve (LOV) systems, achieving a minimal handling and low consumption of samples and reagents, a significant reduction in waste generation and a high frequency of analysis. In the developed methodologies, some spectrometric methods such as ICP-OES and ICP-MS have been implemented as detection techniques instead of radiometric detectors obtaining a fully automated, low-cost and fast yttrium and strontium determinations.

Combination of isotope dilution with liquid chromatography-inductively coupled plasma mass spectrometry for the simultaneous monitoring and evaluation of cadmium and inorganic arsenic in polished rice.

A new monitoring and evaluation technique for cadmium (Cd) and inorganic arsenic (i-As) in rice was developed, where the isotope dilution (ID) method was applied in combination with high performance liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS), following heat-assisted extraction. Cadmium and i-As in a rice sample were extracted using the HNO3-H2O2 extractant, and an appropriate amount of enriched 111Cd was spiked into it. Cadmium and As species were measured simultaneously by LC-ICP-MS. The cadmium concentration was calculated from the isotope dilution analysis, and i-As was determined by the comparison (1 point calibration) method using additional 111Cd as an internal standard. The proposed method provides accurate and precise determination of Cd based on the isotope dilution analysis. Moreover, it can be applied to a rapid screening test to find contaminated rice samples, by means of monitoring the intensity ratios of natural 111Cd and i-As to the additional 111Cd. The developed technique was applied to analyzing multiple rice reference materials, and the measurement results of Cd and i-As agreed with the certified values within the uncertainty range. It is noted that the grain size of rice samples does not affect the extraction data, when the rice sample is crushed into powder less than 850 μm. The proposed method was very useful for the monitoring and evaluation of Cd and i-As in rice as a precise analytical method as well as a screening method.

Estimating R, L and C in Arithmetic Circuits using ML

In Very Large Scale Integration (VLSI) circuits, the estimation techniques for resistors (R), inductors (L), and capacitors (C) heavily rely on segmented circuit analysis, which involves usage of complex mathematical simplification models. These methods have been conventionally applied to estimate the behavior of circuits, but when faced with systems featuring unique circuit architectures, they often encounter inaccuracies and limitations. The significance of adders as fundamental building blocks in intricate circuit design cannot be overstated. In such complex circuits, various parameters, including parasitic resistances, inductances, and capacitances, engage an indispensable effort in the analysis of delays and performance. However, the conventional estimation methods fail to address the complexities of these systems and the impacts of parasitics accurately. To overcome these challenges, this paper proposes a novel approach that harnesses the potential of machine learning algorithms. By integrating machine learning into the estimation process, the research aims to achieve specific and precise analysis methods that can cater to the needs of modern VLSI circuits. The proposed methodology involves collecting a comprehensive dataset using different adder circuits. From each individual adder circuit layout, the relevant information on resistors, capacitors, and inductors is carefully extracted and compiled. This dataset serves as the foundation for training the machine learning models. Three standard machine learning models are employed in this study: adaboost, Tree, and k-Nearest Neighbors (kNN). Their task is to predict the values of resistors, inductors, and capacitors based on the input data from the adder circuits. Among these models, adaboost proves to be the most effective, exhibiting superior performance by achieving a reduced root mean square error of about 0.008. When compared to the Tree and kNN models, adaboost stands out as the optimal choice for accurately estimating the R values in VLSI circuits.

Degradation Analysis: Modeling and Evaluating for Electric Energy Meters under Multi-stress

The measurement accuracy of electric energy meters (EEMs) is crucial for respecting the fairness of the electricity market and the justice of electric energy settlement. However, the basic error (BE) of the measurement suffers from external stress, especially under extreme environments. It is challenging to evaluate the degradation trend of EEMs under multi-stress. To address this issue, this paper proposes modeling and evaluating methods for precise degradation analysis of EEMs under multi-stress. First, an optimized k-nearest neighbor (OKNN) is proposed to correct the outliers, where the stress-related weight and weighting factor are designed. Then, a varied-bias wiener process with hierarchical Bayesian (VWHB) model is introduced to evaluate and explore the impact of stress on the BE. The multi-stress, as well as the BE, are fused to parameterize this impact. Integrating the OKNN and VWHB, a degradation analysis framework is further proposed to model the data and conduct the degradation analysis. Extensive experiments on field data collected from the typical operating environment lab demonstrated that the proposed degradation analysis framework reveals superior performance than some state-of-art approaches. The root of the mean of the square of errors and the mean of absolute value of errors of OKNN-VWHB are the lowest with 0.0356 and 0.0281, respectively, for all the EEMs from three different companies.

Rapid analysis of bioactive compounds from citrus samples by direct analysis in real-time mass spectrometry combined with chemometrics.

Renowned for their nutritional benefits, citrus fruits are harvested at various stages in China for functional food production. This study introduces an innovative analytical method, DART-MS, enabling direct qualitative analysis of citrus samples without the need for preprocessing. Simultaneously, the combination of chemometrics can be applied to distinguish between three different citrus samples: Citri Reticulatae Pericarpium, Citri Reticulatae Pericarpium Viride, and Citri Reticulatae "Chachi". Notably, given the international regulatory concerns surrounding synephrine, a precise quantitative analysis method for synephrine was developed. The limit of detection (LOD) and the limit of quantification (LOQ) were 39 ng mL-1 and 156 ng mL-1, respectively. The recovery rates obtained varied from 98.46% to 100.71%. Furthermore, the intra-day and inter-day precision demonstrated robust consistency, with values spanning 5.0-6.1% and 5.03-6.08%, respectively, offering quicker results compared to those from HPLC-MS, promising a safer assessment of herbal and food products.

Construction of A High Precision Analysis Method for Electromagnetic Fields and Its Application

Construction of A High Precision Analysis Method for Electromagnetic Fields and Its Application

Application of a robust analytical method for quantifying progestins in environmental samples from three Portuguese Estuaries

In the last years, progestins have raised special concerns for their documented negative effects on aquatic species, yet little is known about their environmental levels in surface waters and bioaccumulation in the trophic web. This study aimed to 1) adapt an extraction method for quantifying progestins in freeze-dried matrices, 2) validate the analytical procedure for three matrices: bivalve, polychaete, and crustacean, and 3) characterize levels of the four most prescribed synthetic progestins in key species across three Portuguese estuaries. Through the validated method, progestins were only quantifiable for the crustacean. Values were generally low, peaking with drospirenone values in Ria de Aveiro (1.33 ± 0.26 ng/g ww) and Tagus estuary (1.42 ± 0.55 ng/g ww), while Ria Formosa exhibited the lowest progestin concentrations (< 1 ng/g ww). This study enabled the development of a precise extraction and analytical method for quantifying steroid hormones in three distinct biological matrices.

Spectrophotometric Multi-Component Quantitation of Rosiglitazone, Glibenclamide and Metformin HCl in Pharmaceutical Dosages Form by using Cramer’s Matrix

Objective: This article illustrates the development of a simple, precise and accurate spectrophotometric analysis method for the determination of Rosiglitazone, Glibenclamide and Metformin hydrochloride in their pharmaceutical preparations by using Cramer's matrix. Method: The absorbance of the sample solution was measured at 315.6nm and 229.2nm for the estimation of rosiglitazone and glibenclamide, respectively and at 237.0nm for estimation of metformin hydrochloride by Shimadzu double beam UV-visible spectrophotometer. Results: The result of the analysis for method was tested and validated for various parameters according to ICH guidelines and found satisfactory. The method was successfully applied for the determination of these drugs in their tablet dosage forms. Conclusion: Simultaneous estimation of active ingredients in multicomponent pharmaceutical products normally requires the use of chromatographic separation techniques, like thin layer chromatography, high performance thin layer chromatography, high performance liquid chromatography or gas chromatography etc., followed by their quantitation. But this article illustrates direct spectroscopic estimation of multicomponent formulation by using Cramer's matrix.