Diode Array Research Articles

Development of a carbamazepine determination method based on high-performance liquid chromatography with diode array

Carbamazepine is used in the treatment of convulsive disorders, trigeminal neuralgia and mental illnesses such as bipolar disorder and pain syndromes. It has been found in clinical applications that carbamazepine causes many serious adverse drug reactions, which are associated with drug concentration in blood and dosage in clinical use. Due to its pharmacological properties, carbamazepine can be life-threatening in an overdosage, making the therapeutic drug control of carbamazepine important in any clinical settings. Creation of a method for carbamazepine quantification in biological objects during forensic chemical examinations is an urgent problem. A method of high-performance liquid chromatography with diode array detection is proposed for carbamazepine quantitation. The stability of proposed conditions for carbamazepine analysis has been proved in the modifying study conditions (flow rate of eluent, its composition, pH of buffer, column oven temperature). The relative standard deviation of retention time and areas of chromatographic peaks of carbamazepine did not exceed 0.5%.

Структура и элементная база приёмо-передающего модуля для организации подводной оптической беспроводной системы передачи данных

In the paper, the results of theoretical study of a wireless optical data transmission channel, as well as experimental study of its characteristics, taking into account different configurations of the optical component base of receiving and transmitting modules, were presented. The model of the wireless underwater optical communication channel with pulse-position modulation (4 bits per symbol) of digital data traffic with 100 Mbps is proposed. The model showed that to organize a communication channel on a 10 m path, the use of an array of light-emitting diodes (LEDs) is requires (the amount is up to 20 LEDs). For this case, a sufficiently large route budget will be provided, even with additional factor that reduce the efficiency of light propagation in seawater. The LEDs were chosen to organize the data transmission channel, since they have a wide radiation pattern and allow the implementation of a relatively simple driver circuit. The required optical radiation power is realized with the use of an array of LEDs. Schematic diagrams of the LEDs driver and power supply for the receiving and transmitting modules have been designed. A measuring layout with optical transmitter and receiver blocks has been implemented. The test signal is a regular sequence of pulses with a duty cycle of 2, and a frequency of 1 MHz. In the receiving module, the signal from the output of the pin photodiode is amplified using a wideband operational amplifier. Sets of 3 pin photodiodes and 10 LEDs were selected and tests were carried out to determine options for optical components that provide the best time characteristics of the output electrical signal in terms of delay time, rising and falling edges of pulses in a wireless optical airborne communication channel. Also, measurements were done on an air path with a length of 0.25-3 m using one or two LEDs as part of the transmitting module. It has been experimentally confirmed that the organization of a communication channel with a length of up to 10 m requires about 15-20 light-emitting diodes. Further study involves the designing and testing of a driver for the LEDs array and a prototype transceiver module.

S2ISM: A Comprehensive Approach for Uncompromised Super-Resolution and Optical Sectioning in Image Scanning Microscopy

Image Scanning Microscopy (ISM) enables good signal-to-noise ratio (SNR), super-resolution and high information content imaging by leveraging array detection in a laser-scanning architecture. However, the SNR is still limited by the size of the detector, which is conventionally small to avoid collecting out-of-focus light. Nonetheless, the ISM dataset inherently contains the axial information of the fluorescence emitters. We leverage this knowledge to achieve computational optical sectioning without sacrificing the conventional benefits of ISM. We invert the physical model to fuse the raw dataset into a single image with improved sampling, SNR. lateral resolution, and optical sectioning. We provide a complete theoretical framework and validate our approach with experimental images of biological samples acquired with a custom setup equipped with a single photon avalanche diode (SPAD) array detector. Furthermore, we generalize our method to other imaging techniques, such as multi-photon excitation fluorescence microscopy and fluoresce lifetime imaging. To enable this latter, we take advantage of the single-photon timing ability of SPAD arrays, accessing additional sample information. Our method outperforms conventional reconstruction techniques and opens new perspectives for exploring the unique spatio-temporal information provided by SPAD array detectors.

Toxicological Evaluation of a Polyherbal Formulation (18KHT01) and Validation of UPLC-DAD Method for Quality Control.

Background: 18KHT01 is a novel synergistic composition of Quercus acutissima, Camellia sinensis, Geranium thunbergii, and a small portion of Citrus limon. Our previous report demonstrated that the 18KHT01 exhibits potent antiobesity effects, with synergistic antioxidant, antiadipogenic, and antiobesity activities in diet-induced obese mice. This study explores the toxicity profile and quality control parameters of the 18KHT01 formulation. Methods: Broad-spectrum acute and subacute oral toxicity studies were performed using male and female ICR mice. In order to simultaneous analysis of the 18KHT01 formulation, an ultraperformance liquid chromatography coupled with a diode array detector (UPLC-DAD) method was developed and validated using six marker compounds. Results: Acute oral toxicity evaluation of 18KHT01, administered at single high doses of 2, 2.5, 3, and 5 g/kg, identified 2 g/kg as the no-observed adverse effect level (NOAEL). The LD50 (50% lethal dose) and LD100 (100% lethal dose) of 18KHT01 for male ICR mice were 3.99 and 7.77 g/kg, and those for the female mice were 2.94 and 4.70 g/kg, respectively. In addition, a 30-day repeated dose oral subacute toxicity evaluation indicated that 18KHT01 is safe below 500 mg/kg/day for long-term administration in ICR mice of either sex. UPLC-DAD method validation revealed that each calibration curve for the marker compounds showed good linearity, as well as the validation parameters such as precision, specificity, and accuracy met the acceptance criteria. Conclusion: The present study evidenced the toxicological profile of 18KHT01 polyherbal formulation in mice as well as developed a simple, rapid, and accurate chromatographic method for quality control.

Effects of Gamma Radiation on Microbial Load and Chemical Constituents from Stem Barks of Luehea ochrophylla

Gamma radiation is an effective method for microbial decontamination of plant materials. However, this treatment can induce changes in the chemical structure of plant constituents. Stem barks of Luehea ochrophylla were exposed to different doses of gamma radiation to evaluate decontamination efficiency and changes in chemical composition of plant material including phenolic fraction. The major microbial contaminants of non-irradiated samples were isolated and identified as the fungal species Eurotium chevalieri L. Mangin and Lecythophora decumbens. The dose of 5.0 kGy was effective to achieve total decontamination of the stem barks of L. ochrophylla. The formation of free radicals was verified in the plant material using electron paramagnetic resonance spectroscopy, and was supposed to be related to the trans-aconitic acid, a plant constituent. It was the only secondary metabolite to have its concentration significantly altered with radiation in phenolic fraction, as observed by liquid chromatography with diode array detector coupled to mass spectroscopy (LC-DAD-MS). The trans-aconitic acid was isolated and exposed to gamma radiation in aqueous medium. Its concentration decreased after exposition to a dose of 3.0 kGy, corroborating the supposition of its degradation. Citric acid was the main radiolytic product formed by irradiation of trans-aconitic acid in the presence of water.

Investigating drug residues in Mongolian milk using a newly developed method with high performance liquid chromatography and a photo diode array.

Despite the beneficial impacts of using drugs in animal husbandry, the risks of drug residues in animal products are a concern worldwide. Therefore, most countries have developed systems and methods to detect and monitor drug residues in animal products using high performance liquid chromatography (HPLC) with mass spectrometry (MS). However, MS detectors are not available in all universities; thus, we developed a new method suitable for ultraviolet detection. We first validated a new method targeting tetracycline and albendazole in milk and evaluated these drug residues in 50 samples collected from farms and supermarkets in Mongolia. The practical limit of quantification (PQL) calculated in our newly developed method was suitable to detect the maximum residual limits defined in Codex Alimentarius, and the accuracy and precision of a new method were comparable to previous studies. In particular, inter-day analysis showed great precision, with albendazole showing a 99% recovery rate with ± 3.3 of relative standard deviation (RSD). In addition, we evaluated our drugs contamination, but targeted drugs residues were not detected in the current sample set. However, this may reflect the decreased use of tetracycline in the veterinary field and seasonal use of albendazole in Mongolia. Therefore, these drugs must be continuously monitored. To the best of our knowledge, this is the first report about drug residues in milk published in an international journal by a Mongolian domestic institution. Further investigations of drug residue in Mongolia are urgently needed.

HPLC-DAD Validation Method for Quantifying Gallic Acid in the Aerial Parts of Schinus terebinthifolius

Schinus terebinthifolius Raddi (Anacardiaceae), commonly known as “pimenta rosa”, “aroeira da praia”, “aroeira”, “aroeirinha”, and “cabuí” is frequently used in traditional medicine to address various conditions, including skin wounds, ulcers, tumors, diarrhea, arthritis, as well as urinary and respiratory tract infections. This study aimed to develop and validate an analytical method using high-performance liquid chromatography with diode array detector (HPLC-DAD) for quantifying gallic acid (GA) in methanolic extracts of S. terebinthifolius leaves, branches, and fruits. The chromatographic separations utilized a reversed-phase Zorbax Eclipse XDB-C18 column with an isocratic elution mode of acetonitrile/methanol/water acidified with 0.2% formic acid. The flow rate was 0.8 mL min-1, and detection occurred at 254 nm. The developed HPLC-DAD method demonstrated selectivity, with a GA retention time of 5.263 min and absorption maxima at 220 and 271 nm. The method exhibited high linearity (coefficient of 0.9996), precision (relative standard deviation (RSD) values < 5%), and robustness. Accuracy ranged from 100.28 to 111.71%, with an average recovery of 105.41% and an average RSD of 3.46%. These validated results play a crucial role in assessing and standardizing raw materials containing S. terebinthifolius, emphasizing the reliability of the developed HPLC-DAD method for GA quantification in different plant parts.

A Flash Qualitative Identification Method for the Specific Component in a Mixture Based on Diode Array Detector

This paper proposes a new method of flash qualitative identification (FQI) to qualitatively identify a certain target component from a mixture within half a second by disusing the analytical column, which is a time-consuming unit in current chromatography instruments. First, a Noised Spectrum Identification (NSI) model was constructed for the data set generated directly by diode array detector (DAD) without the process in an analytical column. Then, a method called vector error algorithm (VEA) was proposed to generate an error according to the DAD data set for a mixture and a specific spectrum for the target component to be identified. A criterion based on the error generated by the VEA is used to give a judgement of whether the specific spectrum exists in the DAD data set. Several simulations demonstrate the high performance of the FQI method, and an experiment for three known materials was carried out to validate the effectiveness of this method. The results show that the NSI model concurs with the real experiment result; therefore, the error generated by the VEA was an effective criterion to identify a specific component qualitatively, and the FQI method could finish the identification task within half a second.

Parietin, the Vibrant Natural Dye in Xanthoria parietina.

The use of natural dyes in several areas is regulated by current European and non-European legislation, due to various problems with synthetic dyes. The analysis revealed that the lichen studied: Xanthoria parietina has potential natural dye sources and provides bright colors for extraction solvents. Furthermore, dyed wool and toile fabric have good fastness properties in ammonia fermentation and boiling water, both with and without mordants. The sample dyes with Xanthoria parietina were characterized by several analytical techniques: high-performance liquid chromatography with diode array detection (HPLC-DAD) and electrospray ionization with tandem mass spectrometry (HPLC-ESI-Q-ToF). As compounds from Xanthoria parietina form a complex with mordants and tissues, it is impossible to identify the molecules responsible for coloring using chromatographic techniques. However, we have evaluated the dyeing power of their major molecule, parietin. To further confirm the coloring power of the isolated parietin molecule, we performed a dye test with pure parietin. Thus, CIALAB analyses have shown parietin is the molecule responsible for the coloring obtained by Xanthoria parietina. The utilization of parietin derived from lichens facilitates the development of sustainable dyes for textile coloring, presenting an environmentally friendly alternative to synthetic dyes while simultaneously enriching lichen biodiversity.

Capillary Zone Electrophoresis with Diode-Array Detection as a Tool to Monitor Variations in the Concentration of Organic Acids from the Tricarboxylic Acid Cycle in Human Urine

The tricarboxylic acid (TCA) cycle is responsible for the generation of energy in the human body and may inform about the energy status in different physiological and pathological conditions. It was developed a method to quantify the TCA cycle intermediates (α-ketoglutaric, citric, fumaric, lactic, malic, and succinic acids) by capillary zone electrophoresis with diode array detector (CZE-DAD) in indirect mode. The background electrolyte consisted of 24 mmol L–1 2,6-pyridine carboxylic acid, 76 mmol L–1 β-alanine, and 4 mmol L–1 hexadecyltrimethylammonium hydroxide (pH 4). The method was validated and presented a good linearity (R2 > 0.9922) and adequate limits of detection (0.24-1.84 mg L–1) and quantification (0.74-5.57 mg L–1). The method was successfully applied to samples of individuals with obesity before being submitted to bariatric surgery and one year after the surgery. The citric, lactic, and malic acids were detected in the analyzed samples. To evaluate the changes in concentrations of the TCA intermediates, principal component analysis was carried out, and there was no significant difference between the two sets of samples. Altogether, the data obtained after applying this new method suggest that CZE-DAD could be used to detect and quantify the TCA cycle metabolites in human urine.

Screening of anti-inflammatory activities components of Angelica dahurica root based on spectrum-effect relationship analysis and NF-κB pathway.

Angelica dahurica root (ADR), a commonly utilized herbal medicine in China and other Asian nations, which has anti-inflammatory effects on diverse inflammatory ailments. However, the bioactive components and underlying mechanism responsible for the anti-inflammatory effect of ADR are still unclear. This work attempted to discover the anti-inflammatory bioactive compounds and explore their underlying mechanism in ADR based on spectrum-effect relationship analysis and NF-κB signaling pathway. Chromatographic fingerprints of ADR samples were established by high performance liquid chromatography with diode array detection (HPLC-DAD), and a total of eleven common peaks were selected. Then, high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-Q/TOF-MS) was employed for identification of eleven common peaks in ADR Meanwhile, the anti-inflammatory activities of ADR samples were assessed by inhibition of NO, interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) production in LPS-induced RAW264.7 cells. The spectrum-effect relationships between the eleven common peaks in HPLC fingerprints and anti-inflammatory effects of ADR samples were investigated to identify the potential anti-inflammatory bioactive compounds by grey relational analysis (GRA) and partial least squares regression (PLSR). The spectrum-effect relationship analysis results indicated that six coumarin compounds, including bergapten, xanthotoxin, phellopterin, isoimperatorin, xanthotoxol and imperatorin could be potential anti-inflammatory bioactive compounds in ADR. The further validation experiments also showed that these six coumarins demonstrated significant inhibition of NO, IL-1β, IL-6, and TNF-α production in LPS-induced RAW264.7 cells. In addition, western blot analysis was conducted to explore the mechanisms of two potential anti-inflammatory bioactive compounds (phellopterin and isoimperatorin) by assessing the protein levels in the NF-κB signaling pathway. The western blot results illustrated that phellopterin and isoimperatorin could significantly down-regulate the phosphorylated NF-κB p65 (p-p65), phosphorylated IκBα (p-IκBα) and iNOS, and depress the pro-portion of p-p65/p65 and p-IκBα/IκBα, which indicated that these two coumarins in ADR could potentially exert anti-inflammatory effects by suppressing of NF-κB pathway.

Enhancing verapamil trace determination from biological matrices by bar adsorptive microextraction.

Verapamil is an L-type calcium channel blocker widely used in the treatment of cardiovascular diseases such as hypertension, angina and arrhythmias, requiring accurate therapeutic monitoring to maintain plasma, urine and saliva concentrations within a safe range. In this context, a novel analytical approach has been proposed to determine verapamil in biological samples, using bar adsorptive microextraction coated with reversed-phase polymers followed by high-performance liquid chromatography with diode array detection. Two adsorbents have been chosen, i.e. STRATA-CN and ENVI-18 polymers, showing recoveries from 56.01 ± 2.16% to 96.82 ± 0.61% under optimized experimental conditions, such as sample pH: 10.0 (STRATA-CN) and 8.0 (ENVI-18), 2 h of equilibrium time, stirring speed at 990 rpm, back-extraction solvent using methanol:acetonitrile (1 : 1 v/v), and 1 h under sonication. The analytical method showed linearity from 20 to 600 ng mL-1 (r ≥ 0.99), as well as adequate precision (with RSD% below 15%) and accuracy (with RE% within 15% of the nominal value). Finally, the analytical method was applied to plasma, urine and saliva samples and proved to be a promising alternative for the trace analysis of verapamil in biological matrices.

Comparative Analysis of Phytochemicals and Antioxidant Characterization Among Different Parts of Catharanthus roseus: In Vitro and In Silico Investigation.

Background: The study investigates the antioxidant properties of Catharanthus roseus, focusing on identifying its antioxidant compounds and chemical constituents. We compare antioxidant activities across its root, stem, flower, and leaf and examine the inhibition of reactive oxygen species (ROS)-generating enzymes by the plant's phytocompounds. Methods: We conducted a comprehensive analysis that included proximate analysis, mineral content assessment, and in vitro antioxidant characterization of various plant parts-root, stem, flower, and leaf. The levels of bioactive phytochemicals in both ethanol and mixed-solvent extracts of Catharanthus roseus were quantified using high-performance liquid chromatography with a diode array detector (HPLC-DAD). Additionally, we performed molecular docking studies to explore the interactions of quantified phytocompounds. Results: HPLC-DAD analysis quantified catechin hydrate, catechol, (-) epicatechin, rutin hydrate, trans-cinnamic acid, quercetin, vanillic acid, kaempferol, and trans-ferulic acid in Catharanthus roseus. Despite the ethanol extract having higher total antioxidant properties and flavonoid content, the mixed-solvent extract exhibited higher EC50 for reducing power and lower IC50 for ABTS, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and metal chelating activities. Molecular docking studies indicated that compounds such as catechin, rutin, epicatechin, quercetin, and kaempferol significantly inhibit the ROS-generating enzyme microsomal prostaglandin E synthase 1 (mPGES-1). Conclusions: The mixed-solvent extract had higher levels of catechin hydrate, rutin hydrate, trans-ferulic acid, and vanillic acid, whereas the ethanol extract contained more (-) epicatechin, catechol, kaempferol, quercetin, and trans-cinnamic acid. While the extracts displayed antioxidant activity, the phytoconstituents also inhibited ROS-generating mPGES-1. These results identify key compounds with potential for developing new chemotherapeutic agents against ROS.

Development of a validated RP-HPLC/PDA method for the quantitative estimation of tepotinib in tablet dosage form

A novel and effective reversed-phase high-performance liquid chromatographic (RP-HPLC) technique has been developed to determine the tepotinib, an anti-cancer drug, in a tablet formulation. Furthermore, this method has been validated in accordance with the guidelines of the International Conference on Harmonization. The mobile phase consisted of a mixture of potassium dihydrogen orthophosphate and acetonitrile in a ratio of 15:85 v/v, while the flow rate of the mobile phase was maintained at a constant rate of 1.0 ml/minute. The analysis was conducted using an isocratic approach on a C18 analytical column with dimensions of 250 × 4.4 mm and a particle size of 5 μm. To detect tepotinib, a photo diode array detector was employed, with a wavelength of 284 nm. The quantification of tepotinib was not affected by the presence of excipients. The concentration range of the calibration curve was linear, spanning from 8 to 12 μg/ml. In terms of precision, both intra-day and inter-day relative standard deviations were found to be less than 2%, thus indicating high precision and repeatability. The recovery rate of the compound ranged from 99.76%–101.34 %, with relative standard deviations not exceeding 2%. The limit of detection and quantification were determined to be 0.02 μg/ml and 0.06 μg/ml, respectively. The system suitability parameters were deemed to be within the acceptable range. Therefore, this current report proposes an innovative analytical approach for the evaluation of a recently discovered anti-cancer drug, tepotinib, through the utilization of the RP-HPLC methodology.

A Semi-Automated Molecularly Imprinted Polymer Solid-Phase Extraction Method for Catechin Analysis from Jaboticaba (Plinia sp.) Peel Extract Samples by UHPLC-DAD

Jaboticaba (Plinia sp.), a nutritionally significant Brazilian fruit, is rich in phenolic compounds, such as catechin, known for its biological and pharmaceutical properties. Extracting and studying these compounds is an economic and environmental strategy to fully explore the great potential that these chemical compounds have. Therefore, this study focuses on developing a semi-automated solid-phase extraction method using molecularly imprinted polymer for catechin analysis in jaboticaba peel extracts, coupled with an ultra-high-performance liquid chromatography with a diode array detector. The reported polymer demonstrated superior extractor capacity compared to the non-imprinted polymer. Different extraction parameters were optimized, and the method exhibited a linear range of 10 to 100 µg mL-1 for catechin. The obtained precision with the coefficient of variation was below 7.3%, and the limits of quantification and detection were 12.4 and 4.1 µg mL-1 , respectively. The developed sorbent maintained analytical performance through approximately 40 injections. Results suggest that the reported method could efficiently extract catechin from jaboticaba peels in less than 10 min, providing a promising tool for the rapid investigation of natural products. This selective and sustainable approach demonstrated here contributes to the economic and environmental aspects of catechin extraction and analysis in jaboticaba fruit.

The effect of roasting degrees on bioactive compounds levels in Coffea arabica and their associations with glycated hemoglobin levels and kidney function in diabetic rats

The current study aims to assess the content of coffee oil, diterpenes, caffeine, and chlorogenic acid in coffee beans, and to evaluate the effects of roasting degrees on bioactive compound levels in Coffea arabica and their associations with glycated hemoglobin levels and kidney function parameters in streptozotocin-induced diabetic rats. These constituents were quantified using Soxhlet, liquid–liquid extraction (LLE), and high-performance liquid chromatography (HPLC)-diode array detecto (DAD). The outcomes exhibited a positive correlation between levels of coffee oil and diterpenes with a roasting degree. However, it demonstrated a negative correlation between caffeine and chlorogenic acid with a roasting degree. The male rats were categorized into two sections: healthy (nondiabetic) and streptozotocin-induced diabetic groups. Rats have daily administrated 2 ml of coffee extract using an oral gavage subjected to different roasting degrees for 3 weeks. Fasting blood glucose (FBG), urea, and creatinine in serum were assayed at baseline and end of the experiment. The highest significant elevation (Pa = 0.016) in the mean urea and creatinine levels was noted in the diabetic group administrated with dark coffee extract whereas the lowest elevation was in the diabetic group administrated with green coffee extract. In conclusion, our study has shown that coffee roasting degree may have a potential negative effect on kidney function that may accelerate or exacerbate diabetic nephropathy in induced diabetic rats. A noteworthy change in urea levels was observed in diabetic rats treated with dark-roasted coffee, which might be attributed to the decline in antioxidant constituents: chlorogenic acids and diterpenes.

Multileaf Collimator Modeling and Commissioning for Complex Radiation Treatment Plans Using 2-Dimensional (2D) Diode Array MapCHECK2.

Purpose: This study aims to develop a data-collecting package ExpressMLC and investigate the applicability of MapCHECK2 for multileaf collimator (MLC) modeling and commissioning for complex radiation treatment plans. Materials and methods: The MLC model incorporates realistic parameters to account for sophisticated MLC features. A set of 8 single-beam plans, denoted by ExpressMLC, is created for the determination of parameters. For the commissioning of the MLC model, 4 intensity modulated radiation therapy (IMRT) plans specified by the AAPM TG 119 report were transferred to a computed tomography study of MapCHECK2, recalculated, and compared to measurements on a Varian accelerator. Both per-beam and composite-beam dose verification were conducted. Results: Through sufficient characterization of the MLC model, under 3%/2 mm and 2%/2 mm criteria, MapCHECK2 can be used to accurately verify per beam dose with gamma passing rate better than 90.9% and 89.3%, respectively, while the Gafchromic EBT3 films can achieve gamma passing rate better than 89.3% and 85.7%, respectively. Under the same criteria, MapCHECK2 can achieve composite beam dose verification with a gamma passing rate better than 95.9% and 90.3%, while the Gafchromic EBT3 films can achieve a gamma passing rate better than 96.1% and 91.8%; the p-value from the Mann Whitney test between gamma passing rates of the per beam dose verification using full MapCHECK2 package calibrated MLC model and film calibrated MLC model is .44 and .47, respectively; the p-value between those of the true composite beam dose verification is .62 and .36, respectively. Conclusion: It is confirmed that the 2-dimensional (2D) diode array MapCHECK2 can be used for data collection for MLC modeling with the combination of the ExpressMLC package of plans, whose doses are sufficient for the determination of MLC parameters. It could be a fitting alternative to films to boost the efficiency of MLC modeling and commissioning without sacrificing accuracy.

Assessment of Non-Steroidal Anti-Inflammatories in River Waters of Northeastern of Brazil: Occurrence and Environmental Risk

The environmental impact of pharmaceuticals is a significant concern, as understanding their presence, spread, and harm in coastal regions remains limited. The occurrence of non-steroidal anti-inflammatory drugs (NSAIDs), namely, mefenamic acid (MFN), diclofenac (DCF) and naproxen (NPX) were studied in river waters. Four sample collections were carried out in five points in the dry and rainy seasons. Solidified floating organic drop microextraction (SFODME) coupled with high performance liquid chromatography using diode array detection (HPLC-DAD) were applied to quantify the presence of MFN, DCF and NPX in river water samples. DCF had the highest concentration (640 ng L-1), followed by NPX (410 ng L-1). MFN was not detected in any point within the used working range (limit of detection (LOD) of 0.07 µg L-1). Additionally, an assessment was conducted to evaluate the environmental risk associated with the pharmaceuticals detected in freshwater, specifically in various organisms including algae, mollusks, amphibians, fish, and cnidarians, spanning different trophic levels. The ecotoxicological assessment showed risks ranging from low to high, indicating deleterious effects on several exposed species. No high environmental risk was detected in the sampling areas. Although no immediate negative effects were detected, the potential impact on non-target species should not be disregarded.

Determining Tolfenpyrad in Water Samples Using Liquid-Liquid Extraction with Low Temperature Purification (LLE-LTP)

Tolfenpyrad is an insecticide and acaricide of the pyrazole class, which has been used to control pests in cereal, legume and vegetable crops. Despite its high efficiency, this insecticide is considered highly toxic to humans by Brazilian legislation. Therefore, this study aims to optimize and validate liquid-liquid extraction with low temperature purification followed by analysis by high-performance liquid chromatography with diode array detection to determine tolfenpyrad in water. The results showed that the optimal extraction conditions were achieved using only acetonitrile as extracting phase and 60 min as freezing time. Under these conditions, the extraction method was selective, accurate, and precise, with a recovery of 102.41% and a relative standard deviation of 11.29%. The method was linear from 2.0 to 150.0 µg L-1, with a limit of quantification of 2.0 µg L-1, and the matrix effect was –7.67%. The half-life was 23 days (with sunlight) and 30 days (no sunlight).

Qualitative and quantitative chemical analysis of Leptadenia hastata: exploring a traditional african medicinal plant.

Leptadenia hastata (Pers.) Decne is a commonly used food source and prescribed as a traditional African medicine for treatment of various diseases, such as diabetes, skin disorders, wounds, and ulcers. However, quality control has become a bottleneck restricting the therapeutic development and utilization of this plant. In this study, a reliable method for qualitative and quantitative determination of components in Leptadenia hastata was established. The components of L. hastata were profiled using ultra-high performance liquid chromatography coupled with quadruple time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS). Subsequently, an ultra-high performance tandem diode array detector (UHPLC-DAD)-based method was used for simultaneous quantitative analysis of five major constituents in six batches of L. hastata samples. As a result, 35 compounds were tentatively identified. The quantities of the five constituents (vicenin-Ⅱ, orientin, schaftoside, chrysin 6-C-arabinoside 8-C-glucoside, chrysin 6-C-glucoside 8-C-arabinoside) were determined as 124.8-156.9μg/g, 170.5-216.0μg/g, 61.31-93.73μg/g, 85.13-119.3μg/g and 99.82-129.4μg/g, respectively. This method offers a successful strategy for precise and effective evaluation of the constituents of L. hastata, providing a robust foundation for holistic quality assessment of medicinal plants.