Array Detector Research Articles

Effective method for simultaneous determination of abscisic acid, 3-indolacetic acid and gibberellic acid in commercial plant biostimulants by capillary electrophoresis with diode array detection

Phytohormones, also known as plant hormones, are naturally occurring chemical compounds that regulate various physiological processes in plants. In this work, a capillary electrophoretic coupled to a diode array detector (CE-DAD) method was developed and validated for the simultaneous quantification of abscisic acid (ABA), 3-indolacetic acid (IAA), and gibberellic acid (GA3) in commercial plant biostimulants. Sample preparation was carried out by liquid-liquid extraction using ethyl acetate. CE separation was performed in a fused-silica capillary and background electrolyte (BGE) consisting of borate buffer (50 mM, pH 9.3) applying a high voltage of 20 kV, a pressure of 50 mbar, and injection time of 35 s. The ABA, IAA, and GA3 were detected at 254, 220 and 195 nm respectively. The CE-DAD method validation results showed acceptable specificity, linearity, accuracy, and precision in the concentration range of 10-100 µg/mL for all compounds according to the (International Conference Harmonisation) ICH guidelines. The proposed method was satisfactory applied to the analysis of cited plant hormones in biostimulants and suggest that sample preparation is a reliable step for extraction of phytohormones containing carboxyl groups. Therefore, the developed and validated method could be implemented as a low-cost and fast analytical tool for quality control purposes.

Isolation and Identification of Bitter Compounds in Ginseng (Panax ginseng C. A. Mey.) Based on Preparative High Performance Liquid Chromatography, UPLC-Q-TOF/MS and Electronic Tongue

As a traditional Chinese medicinal herb, ginseng (Panax ginseng C. A. Mey.) is commonly used to treat common diseases, for example, esophageal cancer and myasthenia gravis. Furthermore, ginseng is also processed into a functional food additive that is utilized to improve the freshness of chicken soup and make health wine. Unfortunately, ginseng (Panax ginseng C. A. Mey.) has already shown a noticeable bitterness during its application process. In this research, the bitter substances in ginseng (Panax ginseng C. A. Mey.) after two common preparation processes (water extraction and ethanol extraction) were separated, purified and identified by preparative high performance liquid chromatography (prep-HPLC), high performance liquid chromatography with diode array detector (HPLC-DAD), ultra-performance liquid chromatography coupled with high-resolution quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) and an electronic tongue. The results indicated that compared with the other four bitter compounds, the ginsenoside Rb1 had the highest bitterness value, followed by 20(S)-ginsenoside Rg2, ginsenoside Rg1, ginsenoside Rf and ginsenoside Rb3. Upon the evaluation of results to reduce the bitterness of ginseng extract, we found that the composite embedding system of chitosan adsorption in the ginseng carrageenan gel microsphere (K/MC/MCG) could effectively reduce the bitterness.

A simulation study of the ability to detect power distribution perturbations in the texas A&M TRIGA reactor with self-powered neutron detectors

Given the variety of ways that nuclear reactor core power may be perturbed, reactor operators and developers are keen on understanding the accuracy and convergence time during which perturbations in reactor power distribution may be synthesized (i.e., inferred) from an array of in-core radiation detectors. A simulation study was conducted as described herein using a highly detailed model of the Texas A&M Training, Research, Isotopes, General Atomics Reactor, in which an array of self-powered neutron detectors (SPNDs) was considered for input to the power synthesis methodology. The core power synthesis is conducted using a point-based iterative method with an iterative loop built in to ensure working equation consistency. The forward problem of SPND response to simulated perturbations in reactor power was solved for Gaussian peak-type perturbations in the reactor power distribution. These perturbations varied in variance, amplitude, and core location to assess their impact on synthesis error and to determine the number of iterations required for convergence. A relation between the unique resolvability limit and perturbation width was identified such that the maximum synthesis error increased rapidly when the peak width went beneath this limit (a width approximating half the reactor’s fuel pin-to-pin pitch); this resolvability limit is specific to the SPND configuration and fuel segmentation considered herein. The synthesis error increased linearly with perturbation peak amplitude, whereas the convergence time increased nonlinearly. Perturbations located closer to the center of the core were synthesized more accurately, albeit with a higher number of required iterations. These findings provide a qualitative and quantitative understanding of the accuracy and speed at which different types of spatial power perturbations can be resolved in light-water reactors.

Out‐Of‐Phase Articulation Strategy of CsPbBr3/CsPb2Br5 Perovskite for High Sensitivity X‐Ray Detection

AbstractPolycrystalline CsPbBr3 perovskite materials exhibit exemplary stability, and desirable optoelectronic characteristics are promising for direct X‐ray detection. In this study, polycrystalline 2D phase of CsPb2Br5 hinged on CsPbBr3 is investigated for X‐ray array detector. The incorporation of CsPb2Br5 will modify the carrier transport environment, acting as an amplification factor that significantly enhances carrier mobility and response sensitivity. Finally, the devices demonstrates excellent performance growth. Carrier mobility of CsPbBr3 is improved by a significant 2 orders of magnitude, leading to the sensitivity increased from 2.64 × 104 to 2.58 × 105 µC Gyair−1 cm−2 at a bias voltage of 25 V mm−1. Even at a low bias voltage of 2 V mm−1, still got the value of 3.075 × 103 µC Gyair−1 cm−2, accompanied by a notable increase in the minimum detection limit of 127.9 nGyair s−1 at 0.5 V. Furthermore, a high modulation transfer function (MTF) of 1.57 lp mm−1 is obtained, and achieved a clear and high contrast X‐ray imaging with 64 × 64 TFT board. The perovskite exhibits outstanding light stability (RH ≈ 70 ± 5%) in the atmosphere following the introduction of 2D phase. This excellent carrier transport effect and good long‐term stability present significant commercial potential.

Therapeutic drug monitoring of six contraindicated/co-administered drugs by simple and green RP-HPLC-PDA; application to spiked human plasma

Therapeutic drug monitoring is an important clinical testing of the drugs to monitor their concentrations in plasma in order to guarantee their optimal impact, and to avoid any side effects resulting from drug-drug interactions. A green reversed-phase high-performance liquid chromatographic method using a photodiode array detector (RP-HPLC-PDA) was developed for the simultaneous determination of three carbapenem antibiotics (Imipenem, ertapenem, and meropenem) with the co-formulated drug (cilastatin) and contraindicated drugs (probenecid and warfarin) in spiked human plasma. The separation was achieved at 25 °C using a gradient elution of a mixture of mobile phase A: methanol and mobile phase B: phosphate buffer (pH 3.0). The photodiode array detector was adjusted at 220 nm. Bioanalytical method validation was carried out as per the FDA guidelines, and the method showed good linearity ranges for the six drugs that included their Cmax levels along with low limits of quantification. Based on the results, the method was found to be accurate and precise; with high % recovery and good % RSD, respectively. The method was successfully applied to spiked human plasma, signifying a good potential to be implemented in future TDM studies of these drugs when co-administered together.

Muon measurements at the Pierre Auger Observatory

The Pierre Auger Observatory is the world’s largest detector for observation of ultra-high-energy cosmic rays (UHECRs) (above the energy of 10^{17}1017 eV). It consists of a Fluorescence Detector (FD) and an array of particle detectors known as the Surface Detector (SD). Observations of extensive air showers by the Observatory can be used to probe hadronic interactions at high energy, in a kinematic and energy region inaccessible to experiments at man-made accelerators and to measure the muon component of the shower. Air showers induced by different primaries have different muon contents. With increasing mass of the primary cosmic ray particle, it is expected that the muon content in the corresponding air showers should also increase. Therefore, the determination of the muon component in the air shower is crucial to infer the mass of the primary particle. This is a key ingredient in the searches conducted to pinpoint the sources of UHECRs. Recent results obtained from the Pierre Auger Observatory and other experiments indicate that all the shower simulations underestimate the number of muons in the showers compared to the data. This is the so-called muon deficit. In this paper we briefly review the muon measurements, and present in more detail recent results on fluctuations in the muon number. These results provide new insights into the origin of the muon deficit in air shower simulations and constrain the models of hadronic interactions at ultrahigh energies. With the current design of the surface detectors it is also difficult to reliably separate the contributions of muons to the SD signal from the contributions of photons, electrons, and positrons. Therefore, we also present a new method to extract the muon component of the signal time traces recorded by each SD station using recurrent neural networks. The combination of such algorithms, with the future data collected by the upgraded Pierre Auger Observatory, will be a major step forward, as we are likely to achieve an unprecedented resolution in mass estimation on an event-by-event basis.

Low-energy spectrum of the BULLKID detector array operated on surface

We present the first continuous operation in a surface lab of BULLKID, a detector for searches of light Dark Matter and precision measurements of the coherent and elastic neutrino-nucleus scattering. The detector consists of an array of 60 cubic silicon particle absorbers of 0.34 g each, sensed by cryogenic kinetic inductance detectors. The data presented focusses on one of the central elements of the array and on its surrounding elements used as veto. The energy spectrum resulting from an exposure of 39 h to ambient backgrounds, obtained without radiation shields, is flat at the level of (2.0±0.1stat.±0.2syst.)×106\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$(2.0\\pm 0.1\\,\\mathrm{stat.}\\pm 0.2\\,\\mathrm{syst.})\ imes 10^6$$\\end{document} counts/keV kg days down to the energy threshold of 160±13\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$160\\pm 13$$\\end{document} eV. The data analysis demonstrates the unique capability of rejecting backgrounds generated from interactions in other sites of the array, stemming from the segmented and monolithic structure of the detector.

The unveiling of a levulinic acid isomer in high performance liquid chromatography analysis, a key point for the reliable determination of the catalytic conversion of levulinic acid to γ-valerolactone

This work was motivated by the difficulties found in the analysis and quantification of levulinic acid (LA) and the reaction products resulting from the catalyzed transformation of LA into γ-valerolactone (GVL) using High Performance Liquid Chromatography (HPLC). The starting study carried out with the Zorbax Eclipse XDB-C8 column and UV/Vis detector (or Diode Array Detector, DAD) was puzzling, mainly because two different signals appeared in the analysis of aqueous LA standards. The use of C8-UV/Vis-MS and the measurements with DAD in range wavelength mode (RWL) allowed to suggest the presence of pseudo-LA (sometimes regarded as unidentified impurities in the reactant) together with LA. The finding of an additional LA species was fundamental for the accurate quantification of LA, necessary to provide reliable results in the analysis of the catalytic LA transformation products. The study carried out also allowed the identification of 4-hydroxypentanoic acid (HPA), a labile intermediate compound. The analysis of the target solution (resulting from the explained catalytic system) was also performed with a REZEX ROA-Organic Acid H+ column and Refractive Index Detector (RID) in order to determine its applicability and to check if the results obtained with the two configurations were coherent. The REZEX-RID configuration led to a simpler analysis, as it did not involve the separation of the LA species, and allowed the detection of 1,4-pentanediol (not possible by UV/Vis analysis). The results obtained with REZEX-RID helped to support the need of considering the presence and quantification of an LA isomer in the standard solutions for the right quantification of LA using the C8-UV/vis (or DAD) configuration. The present study clarifies relevant practical aspects of the HPLC-UV/Vis (or DAD) analysis of LA present in aqueous solutions.

A Scoping Review on Carotenoid Profiling in Passiflora spp.: A Vast Avenue for Expanding the Knowledge on the Species.

The Passiflora genus is recognised for its ethnopharmacological, sensorial, and nutritional significance. Yet, the screening of its dietary and bioactive molecules has mainly targeted hydrophilic metabolites. Following the PRISMA-P protocol, this review assessed the current knowledge on carotenoid composition and analysis within Passiflora, examining 968 records from seven databases and including 17 studies focusing on carotenoid separation and identification in plant parts. Those publications originated in America and Asia. P. edulis was the most frequently examined species of a total of ten, while pulp was the most studied plant part (16 studies). Carotenoid analysis involved primarily high-performance liquid chromatography separation on C18 columns and detection using diode array detectors (64.71%). Most studies identified the provitamin A β-carotene and xanthophylls lutein and zeaxanthin, with their geometric configuration often neglected. Only one study described carotenoid esters. Besides the methodology's insufficient description, the lack of use of more accurate techniques and practices led to a high risk of bias in the carotenoid assignment in 17.65% of the articles. This review highlights the opportunity to broaden carotenoid studies to other species and parts within the diverse Passiflora genus, especially to wild, locally available fruits, which may have a strategic role in enhancing food diversity and security amidst climatic changes. Additionally, it urges the use of more accurate and efficient analytical methods based on green chemistry to better identify Passiflora carotenoids.

A comparison of the neutron detection efficiency and response characteristics of two pixelated PSD-capable organic scintillator detectors with different photo-detection readout methods

We characterize the performance of two pixelated neutron detectors: a PMT-based array that utilizes Anger logic for pixel identification and a SiPM-based array that employs individual pixel readout. The SiPM-based array offers improved performance over the previously developed PMT-based detector both in terms of uniformity and neutron detection efficiency. Each detector array uses PSD-capable plastic scintillator as a detection medium. We describe the calibration and neutron efficiency measurement of both detectors using a 137Cs source for energy calibration and a 252Cf source for calibration of the neutron response. We find that the intrinsic neutron detection efficiency of the SiPM-based array is (30.2 ± 0.9)%, which is almost twice that of the PMT-based array, which we measure to be (16.9 ± 0.1)%.

Modeling of Gamma Index for Prediction of Pretreatment Quality Assurance in Stereotactic Body Radiation Therapy of the Liver.

The purpose of this study was to develop a predictive model to evaluate pretreatment patient-specific quality assurance (QA) based on treatment planning parameters for stereotactic body radiation therapy (SBRT) for liver carcinoma. We retrospectively selected 180 cases of liver SBRT treated using the volumetric modulated arc therapy technique. Numerous parameters defining the plan complexity were calculated from the DICOM-RP (Radiotherapy Plan) file using an in-house program developed in MATLAB. Patient-specific QA was performed with global gamma evaluation criteria of 2%/2 mm and 3%/3 mm in a relative mode using the Octavius two-dimensional detector array. Various statistical tests and multivariate predictive models were evaluated. The leaf speed (MILS) and planning target volume size showed the highest correlation with the gamma criteria of 2%/2 mm and 3%/3 mm (P < 0.05). Degree of modulation (DoM), MCSSPORT, leaf speed (MILS), and gantry speed (MIGS) were predictors of global gamma pass rate (GPR) for 2%/2 mm (G22), whereas DoM, MCSSPORT, leaf speed (MILS) and robust decision making were predictors of the global GPR criterion of 3%/3 mm (G33). The variance inflation factor values of all predictors were <2, indicating that the data were not associated with each other. For the G22 prediction, the sensitivity and specificity of the model were 75.0% and 75.0%, respectively, whereas, for G33 prediction, the sensitivity and specificity of the model were 74.9% and 85.7%%, respectively. The model was potentially beneficial as an easy alternative to pretreatment QA in predicting the uncertainty in plan deliverability at the planning stage and could help reduce resources in busy clinics.

Simultaneous separation and determination of seven biphenyl cyclooctene lignans in Schisandra chinensis and its preparations by micellar electrokinetic chromatography with dual organic solvent system.

Gomisin is a natural dibenzo cyclooctene lignan, which is mainly derived from the family Magnoliaceae. It has anti-inflammatory, antioxidant, anti-tumor, anti-aging, and hypoglycemic effects. Gomisins play important roles as medicines, nutraceuticals, food additives, and cosmetics. The objective of this study is to establish a micellar electrokinetic chromatography (MEKC) method for simultaneous separation and determination of seven biphenyl cyclooctene lignans (Gomisin D, E, G, H, J, N, and O) in Schisandra chinensis and its preparations. The method was optimized by studying the effects of the main parameters on the separation. The method has been validated and successfully applied to the determination of seven Gomisins in S.chinensis and its preparations. In the separation system, the running buffer was composed of 20 mM Na2HPO4, 8.0 mM sodium dodecyl sulfate (SDS), 11% (v/v) methanol, and 6.0% (v/v) ethanol. A diode array detector was used with a detection wavelength of 230 nm, a separation voltage of 17 kV, and an operating temperature of 25°C. Under this condition, the seven analytes were separated at baseline within 20 min, and a good linear relationship was obtained with correlation coefficient ranging from 0.9919 to 0.9992. The limit of detection (LOD, S/N = 3) and the limit of quantification (LOQ, S/N = 10) ranged from 0.8 to 0.9μg/mL and from 2.6 to 3.0μg/mL, respectively. The recovery rate was between 99.1% and 102.5%. The experimental results indicated that this method is suitable for the separation and determination of seven Schisandra biphenyl cyclooctene lignan compounds in real samples. At the same time, it provides an effective reference for the quality control of S.chinensis and its preparations.

Standardization and validation of a high-efficiency liquid chromatography with a diode-array detector (HPLC-DAD) for voriconazole blood level determination.

A specialized service for antifungal blood level determination is not available in Colombia. This service is essential for the proper follow-up of antifungal therapies. To standardize and validate a simple, sensitive, and specific protocol based on high-performance liquid chromatography with a diode array detector for voriconazole blood level quantification. We used an Agilent HPLC™ series-1200 equipment with a UVdiode array detector with an analytical column Eclipse XDB-C18 and pre-column Eclipse- XDB-C18 (Agilent). We used voriconazole as the primary control and posaconazole as an internal control. We performed the validation following the Food and Drug Administration (FDA) recommendations. The best chromatographic conditions were: Column temperature of 25°C, UV variable wavelength detection at 256 nm for voriconazole and 261 nm for posaconazole (internal standard); 50 μl of injection volume, 0,8 ml/min volume flow, 10 minutes of run time, and mobile phase of acetonitrile:water (60:40). Finally, retention times were 3.13 for voriconazole and 5.16 minutes for posaconazole. Quantification range varied from 0.125 μg/ml to 16 μg/ml. The selectivity and chromatographic purity of the obtained signal, the detection limits, and the standardized quantification make this method an excellent tool for the therapeutic monitoring of patients treated with voriconazole.

Eco-friendly HPLC Method for the determination of Ranolazine using Cyclodextrin as a green additive to mobile phase

Background: Minimizing the amount of organic solvents is one of the main goals of green analytical chemistry; Therefore, a rapid, simple, sensitive, and environmentally benign method for the determination of ranolazine in bulk and pharmaceuticaldosage form was developed. Methods: The method based on using ethanol s a green solvent: (4mmol/L) sodium sulfobutyl ether-betacyclodextrin SBE-β-CD(pH in aqueous phase=4) (25:75)as a green mobile phase, C18 5𝞵 (4.6*150mm) InertSustain GL Sciences column at room temperature 35°C, the flow rate was 1mL/min, the photo diode array detector was set at 210nm and injection volume was 20μL. Results: The developed method was validated according to International Conference on Harmonization guidelines and showed good linear relationship over the concentration range of 50-150mg/L with the correlation coefficient was obtained R2 = 0.9999. The LOD and LOQ were found to be 1.91 and 5.81mg/L, respectively. The Precision was studied as intra- and inter-day with relative standard deviations not more than 2%, and the accuracy by mean recoveries ranged between100.1-101%. The percentage recoveries of active pharmaceutical ingredient from dosage forms ranged between 99.67 - 100.2%. Addition of cyclodexetrine derivative to the mobile phase, decreases the retention time tR of the compound by 64%, more over, it allowed the method to be greener by the ability to use high percentage of aqueous phase. GAPI and eco-scale were used to evaluate the greenness of the developed method. Conclusion: The results showed that the developed eco-friendly method is suitable for the precise, accurate and rapid determination of Ranolazine in bulk and tablet dosage forms.

Comparative of Antioxidant property of Actinidia Deliciosa extracts by DPPH Assay

Introduction: The kiwi fruit is the edible berry of a cultivar group of the woody vine of several Actinidia species. The most common commercially available, green-fleshed kiwi fruit is the cultivar 'Hayward', which belongs to the Actinidia deliciosa species. Various chemical tests such Quantitative and Qualitative analysis have been carried out on kiwi extract. Methods: The antioxidant activity was evaluated by DPPH, an antioxidative screening of kiwi fruit components (pulp) crude extracts were carried out using specific assay media characterized for the presence of highly reactive species such as 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH). In-vitro the antioxidant enzymes study of DPPH. Result: In our study we have evaluated the antioxidant capacity of flesh of kiwi fruit and also evaluated the antioxidant activity of kiwi fruit constituents along with the array detector for curcumin and piperine. Conclusion: The Kiwi fruit which is highly antioxidant in nature was found to have activity against asthma. It also acts as an anti-oxidant, antidiabetic, anti-ulcer, anti-tumour, hypoglycaemic, hypolipidemic effects, anti-inflammatory and many more. Recent studies show that phytoconstituent such as curcumin and piperine have used to treat asthma.

THz radiation distribution for the identification of infiltrating ductal carcinoma in human breast model: a computational study

With numerous biomedical applications of terahertz (THz) imaging, spectroscopy, and sensing, the THz regime of the spectrum is quickly emerging as an important area of research with the potential to usher in a new era in the healthcare industry. In the medical field, THz radiation has been explored to diagnose and monitor several ailments, including foot diabetes, skin dryness, wounds, and burns. Compared to X-rays, THz waves' phase sensitivity to bodily fluid levels and water results in superior contrast and stronger absorption. This feature makes THz potentially useful for the diagnosis of various malignant tumor forms because cancerous tumors have higher water molecule contents than healthy tissues. The current study presents a computational analysis of a CW-THz point-by-point scanning technique for breast cancer detection. COMSOL multiphysics platform was utilized to create a multilayer three-dimensional breast model containing an irregular-shaped infiltrating ductal carcinoma in the glandular layer. The propagation of the THz radiation in the constructed breast model was simulated based on the radio frequency module and electromagnetic waves in the frequency domain interface. Furthermore, different volumes and locations of the induced tumor were examined. The results demonstrated significant disparities in the acquired electric distribution at different tumor sizes and sites between normal and diseased breasts. The resultant electric field for healthy breast ranged from 1.1 × 10–5 to 0.61 V/m, however, the electric field ranges following tumor addition fluctuate based on its volume and location. Additionally, the position of the THz source and detector array influences the reflected THz signal.

High-Density Glass Scintillators for Proton Radiography-Relative Luminosity, Proton Response, and Spatial Resolution.

Proton radiography is a promising development in proton therapy, and researchers are currently exploring optimal detector materials to construct proton radiography detector arrays. High-density glass scintillators may improve integrating-mode proton radiography detectors by increasing spatial resolution and decreasing detector thickness. We evaluated several new scintillators, activated with europium or terbium, with proton response measurements and Monte Carlo simulations, characterizing relative luminosity, ionization quenching, and proton radiograph spatial resolution. We applied a correction based on Birks's analytical model for ionization quenching. The data demonstrate increased relative luminosity with increased activation element concentration, and higher relative luminosity for samples activated with europium. An increased glass density enables more compact detector geometries and higher spatial resolution. These findings suggest that a tungsten and gadolinium oxide-based glass activated with 4% europium is an ideal scintillator for testing in a full-size proton radiography detector.

In Silico and Chromatographic Methods for Analysis of Biotransformation of Prospective Neuroprotective Pyrrole-Based Hydrazone in Isolated Rat Hepatocytes.

In the current study, chromatographic and in silico techniques were applied to investigate the biotransformation of ethyl 5-(4-bromophenyl)-1-(2-(2-(2-hydroxybenzylidene) hydrazinyl)-2-oxoethyl)-2-methyl-1H-pyrrole-3-carboxylate (11b) in hepatocytic media. The initial chromatographic procedure was based on the employment of the conventional octadecyl stationary phase method for estimation of the chemical stability. Subsequently, a novel and rapid chromatographic approach based on a phenyl-hexyl column was developed, aiming to separate the possible metabolites. Both methods were performed on a Dionex 3000 ThermoScientific (ACM 2, Sofia, Bulgaria) device equipped with a diode array detector set up at 272 and 279 nm for analytes detection. An acetonitrile: phosphate buffer of pH 3.5: methanol (17:30:53 v/v/v) was eluted isocratically as a mobile phase with a 1 mL/min flow rate. A preliminary purification from the biological media was achieved by protein precipitation with methanol. A validation procedure was carried out, where the method was found to correspond to all ICH (Q2) and M10 set criteria. Additionally, an in silico-based approach with the online server BioTransformer 3.0 was applied in an attempt to predict the possible metabolites of the title compound 11b. It was hypothesized that four CYP450 isoforms (1A2, 2C9, 3A4, and 2C8) were involved in the phase I metabolism, resulting in the formation of 12 metabolites. Moreover, docking studies were conducted to evaluate the formation of stable complexes between 11b and the aforementioned isoforms. The obtained data indicated three metabolites as the most probable products, two of which (M9_11b and M10_11b) were synthesized by a classical approach for verification. Finally, liquid chromatography with a mass detector was implemented for comprehensive and summarized analysis, and the obtained results revealed that the metabolism of the 11b proceeds possibly with the formation of glucuronide and glycine conjugate of M11_11b.

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.

Development and validation of an analytical method for acetamiprid determination in plant protection products using HPLC-DAD

AbstractPlant protection products (PPP), crucial for agricultural production, are experiencing increased global demand, particularly with the growing need for food production. To meet this demand, robust analytical methods are essential for confirming the presence and determining active substance concentrations in PPP. This study introduces an analytical method utilizing high-performance liquid chromatography with a diode array detector (HPLC-DAD) for determination of acetamiprid in water-soluble powder formulations. The method, validated according to SANCO/3030/99 rev.5, demonstrated exhibited adequate accuracy and precision, with repeatability expressed as the ratio of the standard deviation (% RSD) to the relative standard deviation (% RSDr) being lower than 1. Recoveries for the active substance at concentrations above 10% ranged from 97% to 103%. The developed method is also characterized by suitable linearity, confirmed by a correlation coefficient &gt;0.99. Specific chromatographic profiles were generated, and acetamiprid content in 180 formulations was analyzed, including reference products. The developed method aligns with “green chemistry” principles, minimizing solvent use and emphasizing energy efficiency. Overall, it offers a comprehensive approach for qualitative and quantitative analysis, ensuring the reliability of PPP quality control.