Method For Quantitative Determination Research Articles

ИЗУЧЕНИЕ ВАЛИДАЦИОННЫХ ХАРАКТЕРИСТИК МЕТОДИК ИСПЫТАНИЯ НА ПОДЛИННОСТЬ И КОЛИЧЕСТВЕННОГО ОПРЕДЕЛЕНИЯ АЦИЗОЛА В СТОМАТОЛОГИЧЕСКОМ ГЕЛЕ

In the quality assurance system for medicinal products, an important role is played by the procedure for validation of analytical methods at the stages of development, testing, technology and serial production. The need for validation at the stage of drug development is due to the fact that it is possible to promptly identify the shortcomings of the method and significantly improve it. The purpose of this study is to validate methods for testing «The authenticity» and «Quantitative determination» of acyzole in dental gel. Materials and methods. To achieve this goal, an active pharmaceutical substance of pharmacopoeial quality was used. When developing methods for testing for “Authenticity,” a reaction with oxalic acid to the zinc cation determined in the composition of acyzole was used. For the quantitative determination of acyzole, the complexometric method was used. The objects of the study were three series of gel samples. Results and discussion. As a result of the research, a method for testing «Authenticity» was developed; it was found that the proposed method is characterized by a negative analytical signal on model mixtures free of the analyte component and placebo, and a positive analytical signal on model mixtures of various compositions containing the analyte component. The validation characteristics of methods for the quantitative determination of acyzole in the gel were studied. positive results were obtained. The proposed methods can be used for inclusion in the regulatory documentation for the developed gel. Conclusion. When assessing the validation characteristics of the proposed methods, it was established that the methods for testing the «Authenticity» and «Quantitative determination» of acyzole in the gel are specific, the methods of quantitative determination are characterized by accuracy and repeatability, a linear dependence in the analytical range of ±20% of the declared amount of acyzole, which allows them to be used for a reliable assessment quality of the developed dental gel.

Development and validation of HPLC-ultraviolet method for quantitative determination of pritelivir in human placental perfusion medium.

A simple and reliable HPLC-ultraviolet (HPLC-UV) method was developed and validated for the quantification of pritelivir in the samples of medium from the experiments utilizing the ex vivo technique of dual perfusion of the human placental lobule. Phenacetin was used as an internal standard (IS) in our HPLC-UV method. Chromatographic separation of pritelivir and phenacetin was achieved on a Waters Symmetry C18 HPLC column (100 × 2.1 mm, 3.5 μm) at ambient temperature (22-25°C). The mobile phase was composed of 50% methanol in deionized water (v/v), the flow rate for isocratic elution was established at 0.25 mL/min, and the detection wavelength for pritelivir and IS was set at 254 nm. Pritelivir and IS were extracted with the protein precipitation method using methanol as a solvent. The calibration curve for pritelivir exhibited linearity (r2 > 0.99) within the concentration range from 0.155 to 6.62 μg/mL. Within- and between-day accuracy ranged from 97% to 110% with relative standard deviation (RSD) values not exceeding 10%. The extraction recovery of pritelivir and IS ranged from 89% to 91% with RSD not exceeding 7%. Pritelivir was stable under the storage and sample handling conditions. This validated HPLC-UV method was utilized to quantify pritelivir in the placental perfusion medium samples, and the resulting concentrations were authenticated with incurred sample reanalysis to confirm the reliability of the method.

MOF-derived multi-"hotspot" 3D Au/MOF-808 (Zr) nanostructures as SERS substrates for the ultrasensitive determination of thiram.

Aconvenient self-assembly methodis proposed for synthesis of 3D Au/MOF-808 (Zr) composite nanostructures with a cerium metal-organic framework loaded with gold nanoparticles. We combine adsorption properties of MOF materials with surface plasmon resonance of noble metals to construct hotspot-dense 3D Au/MOF-808 (Zr) SERS substrates, by using a two-step method of solvothermal and reduction reactions. The results show that optimal SERS substrates are obtained from a volume ratio of gold nanoparticles to MOF-808 (Zr) solution of 4:1 and a self-assembly time of 2h. Rhodamine 6G (R6G) is used as a molecular probe to characterize and analyze SERS properties of substrates of 3D Au/MOF-808 (Zr) prepared under the optimal process conditions, where the substrates are capable to detect R6G concentrations down to 10-10 M with a relative standard deviation of 8.81%. Finally, we applied the SERS substrates of 3D Au/MOF-808 (Zr) to the detection of pesticide thiram, and establish a quantitative determination method. 3D Au/MOF-808 (Zr) provides a sensitive detection of thiram in lake water by SERS with a detection limit of 1.49 × 10-9 M. Application tests show that a SERS enhancement factor of the MOF-based SERS substrates for the detection of thiram can be significantly increased to 5.91 × 105. Thus, the above results indicate that such substrate has high sensitivity, good adsorption, homogeneity, and reproducibility, which can be extended for sensitive detection of pesticide residues in food and environment.

Quantitative 1H NMR Spectroscopy Method for Determination of Anthraquinone Derivatives in Extracts from Rubia tinctorum L. Roots and Rhizomes

Quantitative 1H NMR Spectroscopy Method for Determination of Anthraquinone Derivatives in Extracts from Rubia tinctorum L. Roots and Rhizomes

A novel method for quantitative determination of multiple substances using Raman spectroscopy combined with CWT

The identification of mixed solutions is a challenging and important subject in chemical analysis. In this paper, we propose a novel workflow that enables rapid qualitative and quantitative detection of mixed solutions. We use a methanol-ethanol mixed solution as an example to demonstrate the superiority of this workflow. The workflow includes the following steps: (1) converting Raman spectra into Raman images through CWT; (2) using MobileNetV3 as the backbone network, improved multi-label and multi-channel synchronization enables simultaneous prediction of multiple mixture concentrations; and (3) using transfer learning and multi-stage training strategies for training to achieve accurate quantitative analysis. We compare six traditional machine learning algorithms and two deep learning models to evaluate the performance of our new method. The experimental results show that our model has achieved good prediction results when predicting the concentration of methanol and ethanol, and the coefficient of determination R2 is greater than 0.999. At different concentrations, both MAPE and RSD outperform other models, which demonstrates that our workflow has outstanding analytical capabilities. Importantly, we have solved the problem that current quantitative analysis algorithms for Raman spectroscopy are almost unable to accurately predict the concentration of multiple substances simultaneously. In conclusion, it is foreseeable that this non-destructive, automated, and highly accurate workflow can further advance Raman spectroscopy.

Development and validation of a method for simultaneous quantitative determination of albendazole and praziquantel in coated tablets “AP-helmin”

Adapting modern methods of quantitative analysis of active substances in their joint content in the dosage form and validating them is an integral process of pharmaceutical development. We have developed a drug in the form of coated tablets for the treatment of helminthiases of the digestive system in adults. A feature of this drug is the composition of the API of albendazole and praziquantel in a ratio of 1:4. The aim of this research is to develop methodology for quantitative analysis of both substances by the method of liquid chromatography, determination of their possible mutual influence on the process, as well as validation of the proposed methods. Materials and methods. To meet the research's set purpose, the following tasks were identified: choosing the most rational method for the quantitative determination of albendazole and praziquantel; confirming the absence of the mutual influence of APIs on the results obtained; and validating the selected methods of albendazole and praziquantel analysis. Object of the research conducted included coated tablets “AP-helmin”, series 1-5.2021; pharmacopoeial standard sample (PSS) of albendazole, and PSS praziquantel. Quantitative determination of albendazole and praziquantel was conducted according to SPU, method 2.2.29. Results. The article describes the conditions and stages of the quantitative determination of albendazole and praziquantel and the main indicators of method validation. Conclusions. It was proven that quantification with the liquid chromatography method of both substances is validated, and the substances do not affect each other's analysis in the coated tablets "AP-helmin" following the project of QCM for this drug. All calculated parameters meet the required validation criteria

Simultaneous determination of methanol, ethanol, and formic acid in human serum by HSGC-MS: Method development, validation, and application

The concurrent assessment of methanol, ethanol, and formic acid is imperative for accurate clinical toxicology diagnosis in cases of methanol poisoning. Here, we reported a very simple and reliable headspace gas chromatography coupled with mass spectrometry (HSGC-MS) method for simultaneous quantitative determination of methanol, ethanol and formic acid in blood samples. The derivatization variables for formic acid were optimized. The method exhibits high sensitivity, good selectivity and effective separation factor for methanol (6.51 min), ethanol (8.29 min), and formic acid (11.41 min). The method demonstrates excellent reproducibility and accuracy. The limit of detection (LOD) and the limit of quantification (LOQ) were determined to be 3.14–5.83 μg/mL and 10.47–19.34 μg/mL, respectively. Finally, this method was successfully used for measuring the levels of methanol, ethanol, and formic acid in the serum of patients involved in actual methanol poisoning incidents.

Development and Validation of Novel HPLC Methods for Quantitative Determination of Vitamin D3 in Tablet Dosage Form.

In the present work, an efficient isocratic HPLC method was developed for the precise and accurate estimation of vitamin D3 in tablet form. The chromatographic conditions comprised an L3 silica column (5 µm in particle size, 4.6 mm × 250 mm) with a mobile phase n-hexane/ethyl acetate (85:15 v/v) with a flow rate of 2.0 mL/min and a detection wavelength of 292 nm. The new methodology was validated for accuracy, precision, specificity, robustness, and quantification limits according to an official monograph of USP/BP and ICH guidelines. The peak areas of the six replicates of the homogeneous sample were recorded. The mean value obtained was 67,301, and the relative standard deviation (RSD) was 0.1741. The linearity and range were in the acceptable bounds, i.e., 0.999, which was calculated using regression line analysis. The results show that the method is truly acceptable as the RSD, as the flow rate was 0.81%, while for the mobile phase composition, it was 0.72%, which lies in the acceptable range. The limit of detection (LOD) and the limit of quantification (LOQ) values were 0.0539 µg/mL and 0.1633 µg/mL, respectively. The % RSD of the intra and inter-day precision of the method was deemed acceptable according to the international commission for harmonization guidelines. The developed method has potential to be used for the detection and quantification of vitamin D3 during routine analysis for tablets in dosage form.

Development and validation of method of quantitative determination of flavonoids from the above-ground part of Glycyrrhiza glabra L.

The aim of this study was to determine the optimal extraction factors of flavonoids from the above-ground part of licorice (Glycyrrhiza glabra L.) and to develop a method for their quantitative determination by differential spectrophotometry. The object of the study was collected in the Volgograd region during flowering and dried samples of the herb of the medicinal plant. Ethyl alcohol 70% was chosen as the optimal extractant of flavonoids from the studied raw materials. It was found that the extraction of the maximum amount of flavonoid fraction is observed at three times extraction of plant raw material for 30 minutes each in the ratio with extractant 1:30. Quantitative determination of flavonoid compounds was performed by measuring the optical density of coloured complexes formed in extracts from the above-ground part of G. glabra L. with 2.5% aluminum chloride solution. Detection of the optical density of the tested solutions was conducted at a wavelength of 408 nm, corresponding to the maximum of the standard sample solution of rutin (Sigma, USA) after the addition of 2.5% aluminum chloride solution. Determined by differential spectrophotometry method the content of the sum of flavonoids in recalculation on rutin in extracts from the studied samples of plant raw materials of G. glabra L., obtained under the selected conditions, is 4.34±0.06%. The relative error of determination did not exceed 5%. A validation analysis was also conducted, the results of which showed the specificity, linearity and precision of the developed methodology. The studied validation parameters were within the acceptance criteria.

Atypical components in the composition of nepheline from rocks of the Khibiny massif according to IR spectroscopy data

Nepheline is one of the main rock-forming minerals of the rocks of the Khibiny alkaline massif. Nepheline composition changes depending on the crystallization temperature, which makes it an indicator of rock formation conditions. In addition, nepheline is one of the main concentrators of hydrocarbon gases. The study of nepheline from different rocks of the Khibiny massif by local IR spectroscopy with Fourier transformation (micro-FTIR) has revealed the presence of water and acetylene in its structure. The water content estimated according to the method of statistical quantitative determination of water in nominally anhydrous minerals varies in the range from 0 to 0.78 wt.%. The highest water content has been observed in high-temperature nepheline of early formations (foyaite of the central and outer parts of the massif), and the lowest – in relatively low-temperature nepheline of later rocks of the Main Ring Fault (urtite, apatite-nepheline rock and poikilitic (kalsilite)-nepheline syenite – rischorrite). The study reveals that water enters the structure of nepheline in the form of H2O molecules that occupy vacancies in the potassium sites. The water content in nepheline is controlled by the number of vacancies in its structure. The presence of acetylene has been determined on a qualitative level. Additional studies are required to assess its quantitative content.

Accurate Detection of G-Series Agent Simulants by Pseudo-Multiple Reaction Monitoring on Miniature LIT-MS.

Rapid and accurate on-site detection of chemical warfare agents (CWAs) could defend military and civilian populations against current and emerging chemical weapons. With the development of ambient ionization and linear ion trap technology, the rapid and accurate quantitative determination method of CWAs based on direct ionization and multistage mass spectrometry has attracted widespread attention. In this study, a microliter electrospray ionization-miniature linear ion trap mass spectrometry (LIT-MS) instrument was designed and constructed, and the effects of quadrupole enhanced dipole resonance excitation on the resolution and sensitivity were investigated; consequently, the parameters of CWAs detection were optimized. Based on the broad time-frequency ion excitation technology, accurate multiple reaction monitoring (MRM) quantitative analysis of DMMP (G-series agent simulants, m/z 125 → m/z 93) was obtained. The linear correlation coefficient in the concentration range of 1 to 20 μg/mL could reach 99.02%, and the relative standard deviations (RSD) of continuous repeatability, interday repeatability, and intraday repeatability were all less than 10%. The results showed that the accurate pseudo-MRM detection method based on miniature linear ion trap mass spectrometry for CWAs detection was feasible.

A green perspective on simultaneous HPLC and UV spectrophotometric estimation of Udenafil and Dapoxetine hydrochloride in pharmaceutical formulations

Clinical research has affirmed that the combination of Udenafil and Dapoxetine hydrochloride yields greater improvement in erectile dysfunction compared to the use of individual medications. There is a requirement of precise quantitative method for accurate determination of Udenafil and Dapoxetine when taken together. Consequently, our interest lies in developing and validating analytical methods for the simultaneous estimation of Udenafil and Dapoxetine - Various strategies, such as UV spectrophotometric approaches and an innovative, straightforward, accurate, sensitive, and robust High-Performance Liquid Chromatography (HPLC) procedure, have been explored. An Isocratic HPLC approach was employed using reversed-phase CHEMSIL ODS C18 column (4.6 mm x 250 mm, 5 µm) as a stationary phase and detection wavelength (λ max) 230 nm for the two analytes in the chromatographic column. The mobile phase comprised of (70:30, v/v) mixture of Acetonitrile and 10 mM Ammonium formate buffer having pH 5, adjusted with formic acid. The elution was carried out at a constant flow rate of 1 mL/min. The UV simultaneous equation technique estimated the medicine's quantities and derived a simultaneous equation for DAP and UDN using 2 wavelengths, 230 nm and 298 nm. Furthermore, the two advanced methods underwent rigorous statistical validation, guided by the valuable ICH Q2R1 guidelines, affirming their effectiveness as a successful analytical tool for the concurrent analysis of both tablets in bulk and the synthetic mixture fabricated in the laboratory. To assess the environmental impact of contemporary UV spectrophotometric and HPLC techniques, the Green Analytical Greenness Metric (AGREE) software and the Green Analytical System Index (GAPI) were employed to evaluate the greenness profile. This examination confirmed the method's environmental friendliness concerning solvent usage, chemical ingredients, energy consumption, and waste production. The developed UV method is more sustainable and greener compare to HPLC method for simultaneous estimation of compound, which can be utilised by industry for quantification of each individual drug in their combination products.

Development of a Quantitative Determination Method for Polysorbate 80 in Biologicals by Size-Exclusion High-Performance Liquid Chromatography

Development of a Quantitative Determination Method for Polysorbate 80 in Biologicals by Size-Exclusion High-Performance Liquid Chromatography

Solvents in the industrial synthesis of naphazoline nitrate: implementation of the principles of "Green chemistry" and analysis

The aim: implementation of the principles of green chemistry by regenerating the synthesis solvent 1,2,4-trichlorobenzene and reusing it during the synthesis of the Naphazoline nitrate substance. Study of the influence of the regenerated solvent on the quality of the final product by controlling analytical quality parameters. Development of a method for the quantitative determination and validation of synthesis solvents in a substance. Materials and methods: samples of the substance were synthesized according to the optimized proprietary technology of Farmak JSC. The obtained batches of fresh and regenerated 1,2,4-trichlorobenzene were analyzed according to the monograph of the European Pharmacopoeia on Naphazoline nitrate 0147. Results: the possibility of using regenerated 1,2,4-trichlorobenzene for the synthesis of the substance Naphazoline nitrate has been proven. It is shown that the regenerated solvent does not have a negative effect on the profile of impurities and the polymorphic form of the substance. Analytical quality parameters met the requirements of the internal specification and the requirements of the European Pharmacopoeia monograph. The developed and validated method of quantitative determination of synthesis solvents makes it possible to determine them at the required level. Conclusions: the introduction of regenerated 1,2,4-trichlorobenzene into the synthesis scheme made it possible to significantly reduce the amount of waste per 1 kg of product, which in turn significantly reduced the negative impact on the environment. Analytical quality parameters for regenerated 1,2,4-trichlorobenzene meet the requirements of the internal specification. Industrial series obtained on the regenerated solvent meet the requirements of the monograph of the European Pharmacopoeia. The polymorphic form of the substance batches manufactured on regenerated 1,2,4-trichlorobenzene corresponds to the polymorphic form of the substance batches manufactured on the fresh solvent. The obtained results on the influence of the regenerated solvent on the profile of impurities in the finished substance show the similarity of the profile of the series manufactured on both solvents. According to the requirements of ICH Q3C Impurities: Guideline for residual solvents, a method for quantitative determination of the residual content of 1,2,4-trichlorobenzene in the final product by gas chromatography was developed and validated. The absence of synthesis solvents at the limit of detection is shown

Determination of chromatographic conditions for quantitative assessment of active components in complex nasal spray after manufacturing and expiry date

The aim of the work is the development of chromatographic conditions, the study of the validation characteristics of the method of quantitative determination of phenylephrine hydrochloride, nitrofural, lidocaine hydrochloride and diphenhydramine hydrochloride, panthenol, povidone in the joint presence in the nasal spray by a complex method of liquid chromatography with UV detection. Evaluation of the quantitative content of active components after manufacturing and during the shelf life.
 Materials and methods. Agilent 1260 liquid chromatographs, equipped with a diode-matrix detector from the company "Agilent technologies", USA. Chromatographic columns 250×4.6 mm in size, filled with octadecylsilyl silica gel for chromatography (Zorbax StableBond SB-Aq, Agilent company), mobile phase A - phosphate buffer solution pH 7.0 - acetonitrile P (1650:350), mobile phase B – acetonitrile P; elution mode – gradient; mobile phase flow rate – 1.0 ml/min; detection wavelengths – 220 nm (for panthenol, phenylephrine, povidone, diphenhydramine) and 235 nm (for nitrofural and lidocaine).
 Results. Chromatographic separation conditions were developed for the co-presence determination of six target substances: panthenol, phenylephrine hydrochloride, nitrofural, povidone, lidocaine hydrochloride and diphenhydramine hydrochloride. The suitability of the technique for this task was confirmed by determining the validation characteristics. The methodology at the appropriate level is characterized by specificity, linearity, correctness and convergence in the range of application for panthenol (range 20.33-38.26 mg/ml, ΔZ=0.93 ≤ max ΔZ=3.20, a=0.63  max a=5.12, r = 0.9978  min r= 0.9924), phenylephrine hydrochloride (range 1,70-3,21 mg/ml, ΔZ=0.51 ≤ max ΔZ=3.20, a=0.15  max a=5.12, r = 0.9984  min r= 0.9924), nitrofural (range 0.137-0.257 mg/ml, ΔZ=0.91 ≤ max ΔZ=3.20, a=0.032  max a=5.12, r = 0.9987  min r= 0.9924) povidone (range 20,44-38,50 mg/ml, ΔZ=0.23 ≤ max ΔZ=3.20, a=2,33  max a=5.12, r = 0.9942  min r= 0.9924), lidocaine hydrochloride (range 6,80-12,81 mg/ml, ΔZ=0.34 ≤ max ΔZ=3.20, a=0.66  max a=5.12, r = 0.9988  min r= 0.9924), diphenhydramine hydrochloride (range 1,36-2,56 mg/ml, ΔZ=0.20 ≤ max ΔZ=3.20, a=0.15  max a=5.12, r = 0.9980  min r= 0.9924). There are no significant changes when stored at 25 °C for 6 months.
 Conclusions. An analytical method of quantitative determination of the component composition in an extemporaneous nasal spray by a complex method of high-performance liquid chromatography has been developed. The determined validation parameters confirm the correctness of the methodology. The chemical stability of the dosage form is observed for 6 months

Determination of palladium content in catalysts based on different carbon supports by inductively coupled plasma — atomic emission spectrometry (ICP-AES)

Catalytic processes and technologies are the structure-forming elements of modern chemical, petrochemical and pharmaceutical industries. Prospects of their development are strongly determined by continuous improvement of the existing catalysts and developing the advanced and more efficient ones. Among the available catalysts, an important place belongs to palladium catalysts with carbon supports. Palladium as an active component exhibits unique catalytic properties in various transformations of organic substances: hydrogenation, dehydrogenation, isomerization, dehydrocyclization, carbonylation, oxidation, etc. To control the content of the active component of a catalyst, precise and rapid physicochemical methods are used. ICP-AES shows a good performance in the analytical practice due to the rapidity, sensitivity, high accuracy and selectivity in determining various elements. The aim of the study was to develop a scientifically grounded methodological approach to estimate the palladium content in the catalysts synthesized on different carbon supports made of carbon black and Sibunit, which combines only the acidic decomposition of a sample and analysis by ICP-AES. A series of palladium catalysts synthesized on the carbon supports with different structural and textural characteristics was studied. An urgent goal is to control the content of the active component in the composition of catalysts. This characteristic affects the phase and electronic state of the metal, the structural and textural characteristics and thus determines the activity and selectivity of catalysts during operation. Therefore, quantitative chemical analysis is one of the main methods used to control the quality of catalysts. A method for quantitative determination of palladium concentration, which combines acidic decomposition of a sample and ICP-AES has been developed. The carbon support type was shown to exert no effect on the accuracy and reproducibility of data obtained by the analysis of supported palladium catalysts. The content of palladium in such catalysts can be measured using analytical lines 340.458 and 360.955 nm without lowering the measurement accuracy. The selected conditions of sample preparation make it possible to carry out a quantitative analysis of metal systems based on the carbon support with high accuracy. The relative error in determining the elements did not exceed 4%, the relative standard deviation was no more than 0.04. The results of this work can be used to analyze catalysts of similar chemical composition by ICP-AES.

Validation of the Quantitative Determination Method of the active substance in Angiolin eye drops by spectrophotometry

Today, cataracts are the main cause of vision loss. Therefore, the creation of new ophthalmic medicines (drugs), namely eye drops, based on the active substance angiolin ((S)-2,6-diaminohexanoic acid 3-methyl-1,2,4-triazolyl-5-thioacetate) is an urgent task. Previously, we developed a method of standardization of the active substance – by the spectrophotometry. According to the requirements of the SPhU, the next step was the validation of the developed methods. That became the purpose of our work. Validation of the method of quantitative determination of active substances was carried out according to the following indicators: specificity, linearity, range of application, accuracy, correctness and robustness. In the course of the conducted studies, it was established that the method is characterized by sufficient convergence and correctness, as the criterion of insignificance of the systematic error of the method is fulfilled. The systematic error of the method satisfies the requirements of statistical and practical insignificance. The high value of the correlation coefficient r = 1.0000 and 0.99994 satisfies the requirements of the acceptance criterion (r = 0.9998) and confirms the linearity of the dependence between the amount of Angiolin taken and found in the range from 80% to 120%, according to its nominal content in the drug. The requirements for the linear dependence parameters (a, SD0/b, r) of the Angiolin determination method are met in the entire concentration range from 80% to 120% of the nominal value. Thus, the developed method of standardization of active substances in Angiolin eye drops is valid and can be introduced into the project of QCM (quality control methods).

SPECTROPHOTOMETRIC DETERMINATION OF COPPER(II) IN SOIL IN THE FORM OF A PYROGALLOL RED COMPLEX IN THE PRESENCE OF SURFACTANTS

The spectrophotometric method of quantitative determination of copper(II) by reaction of complex formation with pyrogallol red (in the presence of cation and non-ionic surfactants is proposed. Optimal conditions for analysis have been determined. The method has been tested for the determination of copper(II) in the soil extractor sample. The metrological characteristics of the proposed methodology are evaluate: the detection limit is 0.12 mg/kg, relative standard deviation - less than 0.05.

Express quantitative spectrophotometric determination of 2-(((3-(2-fluorophenyl)- 5-thio-4H-1,2,4-triazol-4-yl)imino)methyl)phenol as an active substance of a medicinal product for the treatment of mycoses

Foot fungus (Candida, molds, dermatophytes) is a fairly common problem. According to the WHO, one-fifth of the world’s population is affected by fungal skin diseases. The prevalence of mycosis of the feet, which affects every second person, is especially increasing. Such a pathology can appear quite unexpectedly and at an inappropriate time. Today, Ukraine is under aggressive pressure from its northern neighbor, and military personnel are not only constantly at risk of receiving combat injuries and wounds, but also due to active hostilities, they may not have access to the necessary hygiene products, get cold, overheat in the sun, or not have time to change their clothes in time. and shoes. The reality is the absence or delay of treatment; the disease progresses and can spread quickly. If mycosis has appeared in one soldier, it can quickly affect others. Therefore, the problem of providing medical and pharmaceutical care is an urgent issue today. Expanding the assortment of drugs with the above action will ensure the needs of the Armed Forces and civilian patients with this dermatological pathology. It will be able to optimize antifungal therapy regimens. For quite a long time, 1,2,4-triazole derivatives have been a promising class of organic compounds that attract the attention of scientists from various fields. It has been proven that 2-(((3-(2-fluorophenyl)-5-thio-4H-1,2,4-triazole-4-yl)imino)methyl)phenol has high antifungal activity. A potential medicinal product based on this medicinal substance can be used for the treatment of various dermatological diseases. To continue the creation of new effective dosage forms for the effective therapy of mycosis of the feet, the urgent task of today is the development of an express, accurate, reliable, and affordable method of quantitative determination of the substance under study. The aim of the work is to develop an express, sensitive and easy-to-implement UV-method for the quantitative determination of 2-(((3-(2-fluorophenyl)-5-thio-4H-1,2,4-triazole-4-yl)imino)methyl)phenol. Materials and methods. The research object is a working standard sample of 2-(((3-(2-fluorophenyl)-5-thio-4H-1,2,4-triazole-4-yl)imino)methyl)phenol provided by NUNVF, LLC “Brovapharma” according to the “Research and production technological regulations for the production of 2-(((3-(2-fluorophenyl)-5-thio-4H-1,2,4-triazol-4-yl)imino)methyl)phenol” developed based on scientific developed by the Ukrainian Military Medical Academy in conjunction with the National Military Medical Clinical Center “Main Military Clinical Hospital” (term of validity of the regulations until 12/31/2034). Isopropanol of grade “chemically pure” was used as a solvent. Analytical equipment: spectrophotometer Specord 200, electronic scales Radwag XA 210.4Y, class A measuring vessels. Results. An express, eco-friendly spectrophotometric method was developed for the quantification of 2-(((3-(2-fluorophenyl)-5-thio-4H-1,2,4-triazole-4-yl)imino)methyl)phenol in isopropanol area, having analytically maximum at 310 nm. The studied solutions are stable for 30 minutes. The analytical technique is linear in the range of concentrations 0.440–0.754 mg/100 ml (70–130 %). The detection and quantification limits were 5.80 % and 15.70 % respectively. The score was 0.76, according to the “greenness” icon of the analytical technique, using the tools AGREE. The prediction of the total uncertainty of the results of the developed method is 1.70 % (max∆As 2.00 %). The proposed method is relevant according to the requirements of the State Pharmacopoeia of Ukraine. Conclusions. Pharmaceutical development, introduction into industrial production and further prescribing by dermatovenerologists of an effective, safe, and harmless medicinal product will help to expand the range and reduce the level of high import dependence of the domestic market of medicinal products, which will create a more complete and balanced system of medicinal supply in Ukraine and optimize antifungal therapy schemes.

Multi-residue method validation of a LC-MS/MS method for quantitative determination of 349 pesticides in tomato and their health risk assessment through monitoring studies

As various pesticides are commonly applied in crop fields, analytical methods based on gas chromatography mass spectrometry (GC-MS) and liquid chromatography mass spectrometry (LC-MS) have been developed. Despite the advantages of these techniques, the market requires the analysis of hundreds of pesticides in a short timeframe but maintaining the sensitivity to assess concentrations below legal limits. To improve the efficiency of analytical methods, the analysis of 349 pesticides in a single chromatographic run was validated for each analyte by determining the analytical parameters according to the criteria described in the SANTE 11312/2021 guide. All the 349 analytes had a recovery between 70–120%, precision < 20%, and as LOQ 0.01 mg/Kg, the lowest acceptable concentration value for pesticides. The method comprises QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) -mediated extraction, followed by LC-MS/MS analysis, eliminating the need for additional clean-up steps. The validated method was used to assess pesticide contamination in 34 tomato samples from Tuscany, observing whether the data obtained were below the legal limits. The 2022 data were compared against samples collected over four years, from 2019. Out of a total of 504 samples, only 8.9% of the 349 targeted pesticides were found. To determine the risk assessment, estimated daily intake (EDI) values were calculated for the total Italian population and for regular consumers. The annual EDI variations were between 1.23E-5 and 2.23E-5 mg/Kg body weight (bw) per day.