Spectrometric Method Research Articles

Enantiomeric Analysis of Chiral Drugs Using Mass Spectrometric Methods: A Comprehensive Review.

Chirality plays a crucial role in the drug development process, influencing fundamental chemical and biochemical processes and significantly affecting our daily lives. This review provides a comprehensive examination of mass spectrometric (MS) methods for the enantiomeric analysis of chiral drugs. It thoroughly investigates MS-hyphenated techniques, emphasizing their critical role in achieving enantioselective analysis. Furthermore, it delves into the intricate chiral recognition mechanisms inherent in MS, elucidating the fundamental principles that govern successful chiral separations. By critically assessing the obstacles and potential benefits associated with each MS-based method, this review offers valuable insights for researchers navigating the complexities of chiral analysis. Both qualitative and quantitative approaches are explored, presenting a comparative analysis of their strengths and limitations. This review is aimed at significantly enhancing the understanding of chiral MS methods, serving as a crucial resource for researchers and practitioners engaged in enantioselective studies.

Selective detection of MnO4- in non-standard explosives by nitrogen-doped carbon quantum dots-copper complexes (NCQDs@Cu)

Nitrogen-doped carbon quantum dots (NCQDs) with bright yellow fluorescence (quantum yield of 27.3 %) were synthesized via a solvothermal method using 2,3-diaminopyridine as the carbon and nitrogen source and ethanol as the solvent. Subsequently, the NCQDs were reacted with Cu2+ in an aqueous solution, forming nitrogen-doped carbon quantum dots-copper complexes (NCQDs@Cu) with great potential for selective determination of MnO4- ions. The aqueous solution of NCQDs@Cu exhibiting a very weak fluorescence (quantum yield of 2.2 %) demonstrated a significant enhancement (quantum yield of 10.0 %) upon interaction with MnO4-(Turn-on). Furthermore, this enhancement remained unaffected by the interfering conventional or unconventional explosives, inorganic ions, and oxidants. Moreover, a good linear relationship existed between the fluorescence intensity of the NCQDs@Cu and the concentration of the permanganate ions in a range of 0 to 5 μmol/L with a detection limit of 32.4 nmol/L. Additionally, the study investigated the underlying principles of the detection mechanism using advanced technologies such as X-ray photoelectron spectroscopy(XPS), The Fourier-transform infrared (FTIR), ultraviolet visible spectrometer (UV–Vis), fluorescence spectrometer and other methods. Finally, the NCQDs@Cu were successfully applied for detecting MnO4- in simulated and actual unconventional explosives, demonstrating a good correlation with standard methods. Therefore, the developed NCQDs@Cu can be used for rapid on-site inspection in explosive incident scenarios. This new method of using carbon dots-metal complexes as fluorescent probes will also provide new ideas for researchers.

Synthesis, characterization, investigation of biological activities and in Silico studies of Bis 4-Bromobenzene sulphonate compounds

In this study, 7 new bis 4-bromobenzenesulfonate (2a-g) derivatives were synthesized. 4-formylphenyl-4-bromobenzenesulfonate (1) was reacted with 1,4-diamino butane, 1,5-diamino pentane, 1,6-diamino hexane, 1,7-diamino heptane, 1,8-diamino octane, 1,9-diamino nonane, 1,10-diamino decane respectively. As a result of the reaction carried out by dry heating, Schiff base-containing alkyl bis 4-bromobenzenesulfonate compounds (2a-g) were obtained. Structure elucidation of the compounds (2a-g) was carried out by FTIR, 1H- and 13C- NMR and mass spectrometric methods. The theoretical studies of compounds 2a and 2b were carried out at DFT/B3LYP/6–311G(d,p) level. Theoretical spectral data were compared with experimental data. The compounds 2a-g were tested against 9 bacterial isolates. . In addition, a total of 3 lung (A549, Calu1 and H1650) and 3 bone (MG63, Saos2 and SW1353) cancer cell lines, and the human lung (Beas2B) and human chondrocyte normal cell line were used to determine the anticancer activities of the synthesized compounds. Their activities against normal cells were examined. Finally, it was utilized molecular docking computations to explore interactions between compounds 2c, 2d, 2f and the Epidermal Growth Factor Receptor (EGFR) and the Vascular Endothelial Growth Factor Receptor (VEGFR1).

Quality and safety of products using GM soybeans in the diet of bulls

The production of high-quality and safe food products in areas contaminated by radiation due to the Chornobyl Nuclear Power Plant accident remains a pressing issue. The aim of this study was to determine the concentration and transfer factors of 137Cs, Pb, Cd, Cu, and Zn in bull products when including various high-protein feeds, such as narrow-leaved lupin and genetically modified soybean, in their diets. The study employed zootechnical methods (design and conduct of a scientific-economic experiment on animals), radiological and spectrometric methods (determination of the concentration of 137Cs, Pb, Cd, Cu, and Zn in feeds, longissimus dorsi muscle, liver, kidneys, and testes of bulls), and statistical methods. It was established that when using GM soybean in the grain mixture, the concentration of 137Cs in the muscle tissue of animals in Group II (experimental) decreased relative to the control by 2.57 Bq/kg, or by 40.5% with a statistically significant difference between groups (P > 0.99). Furthermore, the transfer factor of the radionuclide into the muscle tissue of animals in Group II compared to Group I also had 2.15% abs. lower. The content of Pb in the muscle tissue of bulls in both experimental groups exceeded the maximum permissible concentration by 2.52-2.78 times, while the concentration of Cd in the longissimus dorsi muscle and Cu in the liver of animals in Group II also exceeded sanitary-hygienic requirements by 10.0% and 2.0%, respectively. The introduction of 40% (by mass) of maize grain and 30% of GM soybean into the grain mixture instead of the same amount of wheat and lupin chop during the fattening of animals in the third zone of radioactive contamination contributed to significantly higher content and transfer of heavy metals into muscle tissue: Pb – by 10.3% and 0.10% abs., Cd – 10.0 and 0.03, Cu – 17.2 and 0.53, and Zn – by 17.2% and 2.40% abs. The results of the research can be used in agricultural enterprises and private households that produce livestock products in areas with a high anthropogenic load

Stochastic dynamics mass spectrometric and Fourier transform infrared spectroscopic structural analyses of composite biodegradable plastics

<p>The (partial) replacement of synthetic polymers with bioplastics is due to increased production of conventional packaging plastics causing for severe environmental pollution with plastics waste. The bioplastics, however, represent complex mixtures of known and unknown (bio)polymers, fillers, plasticizers, stabilizers, flame retardant, pigments, antioxidants, hydrophobic polymers such as poly(lactic acid), polyethylene, polyesters, glycol, or poly(butylene succinate), and little is known of their chemical safety for both the environment and the human health. Polymerization reactions of bioplastics can produce no intentionally added chemicals to the bulk material, which could be toxic, as well. When polymers are used to food packing, then the latter chemicals could also migrate from the polymer to food. This fact compromises the safety for consumers, as well. The scarce data on chemical safety of bioplastics makes a gap in knowledge of their toxicity to humans and environment. Thus, development of exact analytical protocols for determining chemicals of bioplastics in environmental and food samples as well as packing polymers can only provide warrant for reliable conclusive evidence of their safety for both the human health and the environment. The task is compulsory according to legislation Directives valid to environmental protection, food control, and assessment of the risk to human health. The quantitative and structural determination of analytes is primary research task of analysis of polymers. The methods of mass spectrometry are fruitfully used for these purposes. Methodological development of exact analytical mass spectrometric tools for reliable structural analysis of bioplastics only guarantees their safety, efficacy, and quality to both humans and environment. This study, first, highlights innovative stochastic dynamics equations processing exactly mass spectrometric measurands and, thus, producing exact analyte quantification and 3D molecular and electronic structural analyses. There are determined synthetic polymers such as poly(ethylenglycol), poly(propylene glycol), and polyisoprene as well as biopolymers in bags for foodstuffs made from renewable cellulose and starch, and containing, in total within the 20,416–17,495 chemicals per sample of the composite biopolymers. Advantages of complementary employment in mass spectrometric methods and Fourier transform infrared spectroscopy is highlighted. The study utilizes ultra-high resolution electrospray ionization mass spectrometric and Fourier transform infrared spectroscopic data on biodegradable plastics bags for foodstuffs; high accuracy quantum chemical static methods, molecular dynamics; and chemometrics. There is achieved method performance |<em>r</em>| = 0.99981 determining poly(propylene glycol) in bag for foodstuff containing 20,416 species and using stochastic dynamics mass spectrometric formulas. The results highlight their great capability and applicability to the analytical science as well as relevance to both the fundamental research and to the industry.</p>

A multianalyte LC-MS/MS method for accurate quantification of Nitrosamines in Olmesartan tablets

This research summaries the development, optimization and validation of liquid chromatography tandem mass spectrometric (LC-MS/MS) method for concurrent measurement of seven nitrosamines viz; NDMA, NDEA, NDIPA, NDPA, NEIPA, NMPA & NMBA in Olmesartan tablet. Controlling these nitrosamines at trace levels is imperative for ensuring the safety of drug substances and products for consumption. Various regulatory authorities stress the significance of utilizing highly sensitive analytical methods to precisely measure nitrosamines at trace levels. The method applied effective chromatographic separation and optimized parameters for mass spectrometric detection. Detection was carried out using APCI positive ion mode. Chromatographic separation was achieved using a Thermo Accucore PFP column (150 mm x 4.6 mm, 2.6 µ), with a simple gradient elution of mobile phase consisting of 0.1 % formic acid in water (mobile phase A) and methanol (mobile phase B). The total run time was 20 min, with a flow rate of 0.800 mL/min.The method was validated according to the International Council on Harmonisation (ICH Q2 (R2)) guidelines. The established method demonstrated excellent linearity (R2> 0.99) and sensitivity for all the nitrosamines. Detection and quantification limits were sufficiently low for trace nitrosamine levels having good S/N ratio. The method showed good accuracy in Olmesartan tablet samples, with recoveries ranges between 80 % to 120 %. The new analytical approach has exceptional repeatability and reliability, making it possible to precisely quantify the levels of seven nitrosamines in Olmesartan medoxomil tablets in a single analytical run.

The role of Nuclear Magnetic Resonance (NMR) spectroscopy in cattle metabolism

Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful analytical tool that has significantly advanced the understanding of cattle metabolism. Nuclear Magnetic Resonance (NMR) spectroscopy plays a pivotal role in the study of cattle metabolism, offering distinct advantages over other spectrometric methods. NMR spectroscopy is a powerful analytical tool that provides detailed molecular insights by exploiting the magnetic properties of atomic nuclei. Unlike mass spectrometry and infrared spectroscopy, NMR does not require extensive sample preparation or destruction, preserving the integrity of biological samples. This non-invasive nature is particularly beneficial for longitudinal studies in cattle, where metabolic changes over time are of interest. One of the key strengths of NMR spectroscopy is its ability to simultaneously detect and quantify a broad range of metabolites in complex biological matrices, such as blood, urine, and tissue extracts. This comprehensive metabolic profiling is crucial for understanding the biochemical pathways and physiological states in cattle. NMR's high reproducibility and quantitative accuracy further enhance its suitability for metabolic studies, enabling precise monitoring of metabolic fluctuations in response to dietary changes, environmental stressors, or disease conditions. NMR spectroscopy also offers unique advantages in elucidating structural information about metabolites. Through multidimensional NMR techniques, researchers can determine the molecular structure and conformation of metabolites, providing deeper insights into metabolic functions and interactions. This structural elucidation is often challenging with other spectrometric methods, which may lack the resolution or require derivatization of samples. Moreover, NMR spectroscopy's non-destructive nature allows for the analysis of living tissues and in vivo studies, facilitating real-time monitoring of metabolic processes. This capability is instrumental in studying dynamic metabolic responses and adaptations in cattle under different physiological states. Additionally, the development of advanced NMR techniques, such as high-resolution magic angle spinning (HR-MAS) and hyperpolarization, has further expanded the scope of NMR applications in metabolic research. NMR spectroscopy stands out as a superior method for studying cattle metabolism due to its non-destructive approach, comprehensive metabolic profiling, structural elucidation capabilities, and potential for in vivo analysis. These advantages make NMR an indispensable tool in advancing our understanding of cattle metabolism and improving livestock health and productivity. Keywords: Nuclear Magnetic Resonance (NMR), Cattles, Metabolomics.

Dissolved and particulate metals and metalloids in the eastern Mekong Delta, Vietnam

The article reports the concentration levels of particulate and dissolved metals and metalloids (Be, Se, Sb, Tl, V, Pb, Cd, Cu, Zn, Ni, Mo, Co, Fe As, Ag) in the eastern region of the lower Mekong Delta (Vietnam) in order to assess their possible influence on the environmental quality of river water. To measure the concentrations of trace elements, a mass spectrometric method was used. The critical particulate elements had included V, Cu, Ni, Co, Pb, Cd and potentially critical – Mo, Ag, Se, Tl. In the dissolved phase these were Cu, Zn, and Pb, Cd, Co, Ag, Se respectively. The high accumulation ability of studied elements to suspended particulate matter (102–107) suggests their important role in the distribution of elements. The water salinization boundary in the riverbeds of the delta moves upstream 30–50 km further in the dry season compared to the wet season.

Statistical comparison for assessing agreement between two mass spectrometric methods for the analysis of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs) in contaminated soils

A gas chromatography coupled to high-resolution mass spectrometry (GC-HR/MS) has been used as the standard method for the quantification of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs), which are regulated at screening and action levels in the environment. However, several alternative methods have been attempted due to the disadvantage of its high cost. Although a gas chromatography with triple quadrupole mass spectrometry (GC-QqQ-MS/MS) has been used in a wide variety of sample matrices, showing that they are interchangeable, there has been a lack of comprehensive studies on statistical agreement with GC-HR/MS. In this study, a pairwise comparison of the total concentrations of PCDDs/Fs in 90 soil field samples obtained by two mass spectrometric methods was performed using the Passing-Bablok (P&B) regression and Bland-Altman (B&A) analysis for the method comparison. According to the result of the B&A analysis, the concentration range of PCDDs/Fs was between 98.2 and 1760 pg/g showed good agreement between two methods at the 95 % confidence level (CL). Although there was a large discrepancy between the two methods in the low concentrations (<16.5 pg/g of PCDDs/Fs), this result was similar to the P&B regression analysis. As the verification results by B&A and P&B regression analysis, the interchangeable concentration range between the two methods was confirmed to be adequate for the monitoring of PCDDs/Fs regulating levels in soils.

Trifolium pratense as a novel phytogenic supplement, is an anticoccidial agent in chickens

Coccidiosis, caused by a protozoan parasite of the genus Eimeria, is one of the most severe contagious parasite diseases affecting the poultry industry worldwide. Using phytogenics to prevent chicken coccidiosis is a strategy aimed at combating the increasing issue of drug-resistant strains of Eimeria spp. This study demonstrates the anticoccidial activities of a medicinal herb, Trifolium pratense (TP) powder, and its ethanolic extract (designated TPE) against Eimeria spp. TPE exhibited significant suppressive activity against E. maxima oocyst sporulation and E. tenella sporozoite invasion and reproduction in Madin-Darby bovine kidney cells. Furthermore, administration of basal chicken diets containing TP powder or TPE to Eimeria-infected chickens significantly reduced the output of oocysts and severity of intestinal lesions. Dietary supplementation with TP significantly improved relative weight gain in E. tenella- and E. acervulina-infected chickens, while there was no significant improvement in E. maxima-infected chickens. The anticoccidial activities of TP and TPE on E. acervulina, E. tenella and E. maxima were further supported by anticoccidial index scores, which showed greater efficacy than those of amprolium, a commercial coccidiostat used in poultry. TP supplementation positively impacted the primary metabolism of chickens challenged with E. tenella or E. acervulina. The chemical fingerprints of TPE were established using liquid column chromatography; TPE contained 4 major compounds: ononin, sissotrin, formononetin, and biochanin A. In addition, various spectrometric methods were used to ensure the batch-to-batch consistency of TP/TPE. In conclusion, T. pratense is demonstrated to be a novel phytogenic supplement that can be used to control Eimeria-induced coccidiosis in chickens.

Application of fluorescent carbon quantum dots functional modified carboxymethyl cellulose film in toluene gas specific detection

With the increasing consumption of organic solvents in chemical and pharmaceutical industries, the environment pollution of volatile organic compounds (VOCs) has become an urgent problem. Therefore, the rapid-visual detection method is of great significance in the analysis of VOCs. Based on the fluorescence quenching/enhancement mechanism of carbon quantum dots (CQDs), with the help of carboxymethyl cellulose membrane with porous and large specific surface area structure, a series of green CQDs@carboxymethyl cellulose composite film (CQDs@CMC composite film) was prepared in this study. In the typical-targeted pollutants (toluene) detection application, a fluorescence spectroscopy method was established which could achieve the high sensitivity and strong specificity detection. The mainly conclusions were as follows: The fluorescence spectrometric detection method for toluene: A kind of hydrophobic Lmi/Bet CQDs@CMC composite film was prepared and characterized with imidazole/betaine CQDs and porous carboxymethyl cellulose composite film as raw materials. The toluene detection performance was studied, and the recognition mechanism was explored. The results showed that toluene enhanced the fluorescence of Lmi/Bet CQDs@CMC composite film. The fluorescence intensity of composite films was proportional to toluene concentration when the toluene concentration ranged from 200 to 2200 mg/L. The detection limit of toluene was 1.169 mg/L, which provides a theoretical basis for the detection of toluene by fluorescence spectrometry.

Breaking barriers in pharmaceutical analysis: Streamlined UV spectrometric quantification and stability profiling of haloperidol and methylparaben in liquid formulations

This study aims to quantify haloperidol and methylparaben in a liquid pharmaceutical formulation (2 mg/ml) using UV spectrometry and the simultaneous equations method. Additionally, we explored the stability of haloperidol under various stress conditions. The UV analysis revealed maximum absorption peaks at 248 nm for haloperidol and 256 nm for methylparaben, using a 1 % (v/v) lactic acid solution as the solvent. Method validation, conducted according to ICH guidelines, affirmed the method's reliability, showing excellent results in terms of linearity, precision, accuracy, and sensitivity. The method allows direct application to finished products, enabling simultaneous quantification without extractions. Its simplicity, speed, and cost-effectiveness make it ideal for routine controls in pharmaceutical industry haloperidol solution analyses. The method extends to monitoring forced degradation, indicating photolytic and hydrolytic degradation under acidic and basic conditions, while affirming thermal and oxidative stability. This proposed UV spectrometric method serves as a compelling alternative to pharmacopeia-recommended techniques, simplifying simultaneous determination of the active ingredient and preservative. This streamlines analysis, reducing time and costs. Additionally, it proves valuable in small industries lacking sophisticated instrumentation, offering insights into active ingredient behavior during forced degradation.

Extraction of kaempferol derivatives from Zygophyllum paulayanum and its diverse biological activities

Zygophyllum paulayanum (Zygophyllaceae), is a plant commonly found in the desert region, well-known for its antioxidant, anticancer, wound healing, anti-inflammatory and antibacterial, properties. In this present work, we have studied the extraction of kaempferol derivatives from Z. paulayanum which showed excellent biological activities. The whole plant (root, leaves and stem) was extracted using ethanol, hydrolysed with HCl, and studied for the identification of active molecules. Different techniques like TLC, HPLC, and LCMS have been used to identify and confirm the kaempferol aglycone flavonoid. A mass spectrometric method based on electrospray ionisation has confirmed the presence of kaempferol flavonoid. Apart from the hydrolysed extract, the unhydrolyzed extract was also tested for LCMS which confirms the presence of glycosides such as kaempferol 3-O-beta-D-glucopyranosyl-7-O-alpha-L-rhamnopyranoside, kaempferol 3-O-β –rutinoside and kaempferol-3-o-rhamnoside. Both extracts of Z. paulayanum exhibited superior antioxidant, anti-inflammatory, antimicrobial, phytoestrogenic and cytotoxic properties which might be due to the presence of kaempferol derivatives.

Phytoecdysteroids from Dioscorea dumetorum (Kunth) Pax. and their antioxidant and antidiabetic activities

Diabetes is a significant global health challenge, affecting circa 540 million adults worldwide. Dioscorea dumetorum, a Nigerian folkloric antidiabetic plant is severely understudied in terms of its bioactive phytochemical constituents. Antidiabetic guided isolation of the tubers and peels of D. dumetorum afforded three phytoecdysteroids bearing a cis-fused A/B ring junction including two new ones: 24-hydroxymuristerone A (1) and 24-hydroxykaladasterone (2), alongside the known muristerone A (3). Additionally, 2,2′,7,7′-tetramethoxy-[1,1′-biphenanthrene]-4,4′,6,6′-tetraol (4), batatasin I (5), and dihydroresveratrol (6) were isolated. Structural elucidation relied on spectroscopic, spectrometric methods, and comparison with existing literature. The ethyl acetate extracts of both the tubers and peels of D. dumetorum exhibited the highest phenolic content, correlating with potent antioxidant activity. Compounds 4 (IC50 = 0.10 mg/mL) and 6 (IC50 = 0.22 mg/mL) demonstrated superior inhibitory effects against α-glucosidase compared to acarbose (IC50 = 0.63 mg/mL). In contrast, compounds 3, 4, and 5 showed reduced α-amylase inhibition, with IC50 values of 2.58, 3.78, and 1.12 mg/mL, respectively, compared to acarbose (IC50 = 0.42 mg/mL). These observed bioactivities validate the traditional use of D. dumetorum and contribute valuable phytochemical data to the scientific literature of the species.

Novel tetraaza macrocyclic Schiff base complexes of bivalent zinc: microwave-assisted green synthesis, spectroscopic characterization, density functional theory calculations, molecular docking studies, in vitro antimicrobial and anticancer activities.

In the present manuscript, novel macrocyclic Schiff base complexes [Zn(N4MacL1)Cl2-Zn(N4MacL3)Cl2] were synthesized by the reaction of ZnCl2 and macrocyclic ligands (N4MacL1-N4MacL3) derived from diketone and diamines under microwave irradiation method and conventional method. The structures of the obtained complexes were identified by various spectrometric methods such as Fourier transformation infra-red (FT-IR), nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HR-MS), powder X-ray diffraction, molar conductivity, and UV-vis. The structures of the synthesized compounds were optimized by using the def2-TZV/J and def2-SVP/J Coulomb fitting basis sets at B3LYP level in density functional theory (DFT) calculations. The macrocyclic Schiff base complexes exhibited higher activities against Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus), Gram-negative bacteria (Escherichia coli and Xanthomonas campestris), and fungal strains (Fusarium oxysporum and Candida albicans) in comparison to macrocyclic Schiff base ligands. Furthermore, the newly synthesized macrocyclic compounds were assessed for their anticancer activity against three cell lines: A549 (human alveolar adenocarcinoma epithelial cell line), HT-29 (human colorectal adenocarcinoma cell line), and MCF-7 (human breast adenocarcinoma cell line) using the MTT assay. The obtained results showed that the macrocyclic complex [Zn(N4MacL3)Cl2] displayed the highest cytotoxic activity (2.23 ± 0.25µM, 6.53 ± 0.28µM, and 7.40 ± 0.45µM for A549, HT-29, and MCF-7 cancer cell lines, respectively). Additionally, molecular docking investigations were conducted to elucidate potential molecular interactions between the synthesized macrocyclic compounds and target proteins. The results revealed a consistent agreement between the docking calculations and the experimental data.

Development of UPLC–MS/MS method for the simultaneous quantification of valproic acid and phenytoin in human plasma and application to study pharmacokinetic interaction in epilepsy patients

Valproic acid and phenytoin are two prevalent antiepileptic medications known for their narrow indices and propensity for cardiovascular and respiratory system toxicity. Therefore, therapeutic drug monitoring (TDM) of valproic acid (VAL) and phenytoin (PHE) concentrations in patient plasma is extremely beneficial for improving clinical choices, avoiding adverse reactions, and optimizing treatment for individual patients. In this study, a rapid and sensitive ultra-performance liquid chromatographic tandem mass spectrometer (UPLC-MS/MS) method was developed and validated for the simultaneous quantitative determination of valproic acid (VAL) and phenytoin (PHE) in human plasma. Negative electron spray ionization (ESI-) mode with selective ion recording (SIR) was employed to determine the transitions of m/z 142.98 and m/z 250.93 for VAL and PHE, respectively. The internal standard (IS) betamethasone (BETA) was ionized using positive electron spray ionization (ESI+) and detected by multi-reaction monitoring (MRM) mode to obtain precursor ions and specific fragment ions for quantification, and the MRM transition was chosen to be m/z 393.17 → 355.16. The separation was performed using a Phenomenex Synergi Hydro-RP (4 μm, 250 × 4.6 mm, I.D.) with an isocratic mobile phase consisting of acetonitrile – water (75:25, v/v) at a flow rate of 0.8 mL/min. The column temperature was maintained at 25 °C. The lower limit of quantification of VAL and PHE was 3.6 μg/mL and 0.72 μg/mL, respectively, which resulted in a recovery of more than 85 % for most analytes. According to US-FDA bioanalytical technique validation, the specificity, intra- and inter-day precision and accuracy, matrix effect, carryover, dilution, and stability of all analytes were within acceptable ranges. This analytical method was successful in evaluating the levels of valproic acid and phenytoin in human plasma from epileptic patients.

Indicator displacement-based colorimetric assay for dibutyl phthalate in pharmaceutical products with titanium(IV)-pyridylazo resorcinol (PAR)

Taking advantage of the competitive binding affinity towards Ti(IV) between 4-(2-pyridylazo) resorcinol (PAR) and phthalate, a simple indicator displacement (ID)–based colorimetric assay was designed for indirect determination of a well-known phthalic acid ester, dibutyl phthalate (DBP). The indicator PAR and Ti(IV) formed a purplish-red-colored Ti(IV)-PAR complex (λmax = 540 nm) at a 1:1 ratio. In the presence of pre-hydrolyzed DBP, colorless complex formation of phthalate ion (emerging from alkaline hydrolysis of DBP) with Ti(IV) resulted in a hypsochromic shift in absorbance maximum, accompanying a color change from purplish-red to yellowish-orange (λmax = 390 nm) by the release of PAR from Ti(IV)-PAR system. Based on this mechanism, the linear response range of the system for DBP was found to lie between 0.16 and 0.37 mmol L–1 with an experimental detection limit of 11.6 µmol L–1. The recommended Ti(IV)-PAR system was successfully applied to DBP-containing pharmaceutical products (as real sample) after a simple clean-up process for removing possible water-soluble interferents. The analytical results obtained from the recommended method (by applying the standard addition approach) and the reference liquid chromatography-tandem mass spectrometric (LC–MS/MS) method were statistically compared using DBP-extract of the drug samples. Consequently, a simple and selective colorimetric ID strategy was proposed for the analysis of DBP in pharmaceuticals for the first time.

In-Vitro Dissolution Study of Solid Dispersion Adsorbate of Nateglinide by Eco-Friendly Liquid Chromatography-Tandem Mass Spectrometric Method through Harmonized Approach of White Analytical Chemistry and Analytical Quality by Design

In-Vitro Dissolution Study of Solid Dispersion Adsorbate of Nateglinide by Eco-Friendly Liquid Chromatography-Tandem Mass Spectrometric Method through Harmonized Approach of White Analytical Chemistry and Analytical Quality by Design

The Study of Composite Materials Properties Based on Polymers and Nano-Additives from Industrial Wastes from Kazakhstan.

This research is aimed at studying the properties of polymer anticorrosion coatings based on ED-20 resin widely used in practice and industrial wastes. In this work, three basic types of nanoscale nanofillers were chosen: dispersed particles-microsilica, microspheres obtained at Kazakh enterprises, and carbon nanotubes. Physicochemical research methods were used in the research: a laser analyzer for studying the dispersibility of industrial waste and spectrometric research methods. The properties of materials were investigated by standardized methods. The obtained results show that the introduction of microsilica and microspheres obtained at Kazakhstani enterprises, used as additives, improves both the physical and mechanical properties of epoxy composites compared to the standard (control) material. The results of experiments have shown that the optimal content of additives of microsilica and microspheres provides an improvement in the physical and mechanical properties of epoxy composites in comparison with the standard (control) material. Studies have shown that the introduction of microspheres into ED-20 polymer increases impact toughness. The introduction of microsilica into the matrix contributes to the increase of elastic modulus. Experimental studies of optical properties of samples of carbon composite polymer films based on polystyrene (PS) with additives of carbon nanotubes C60 and C70 and multilayer carbon nanotubes were also carried out. The experimental results obtained for the optical properties of polymer composites based on basic polymers from solid waste and carbon nanotubes showed that the optical properties of polymer composites undergo noticeable changes.

Comparative studies of essential oils from Matricaria recutita L.

The aim of the work is to determine the component composition of the essential oil of medicinal chamomile, grown on the educational and research site of medicinal plants of Zaporizhzhia State Medical and Pharmaceutical University (ZSMPHU), and commercial essential oil that was purchased via the Internet. Materials and methods. The object of the study was chamomile essential oil obtained by hydrodistillation and commercial oil. Qualitative and quantitative determination of the components of essential oils was established using the chromato-mass spectrometric method on a high-performance gas chromatograph “Agilent 7890B GC System” (Agilent, SantaClara, CA, USA) with a mass spectrometric detector “Agilent 5977 BGC/MSD” (Agilent, SantaClara, CA, USA). Results. Dominant compounds of essential oil of chamomile, grown on the educational and research site of medicinal plants ZSMPHU were 2H-pyran-3-ol, tetrahydro-2,2,6-trimethyl-6-(4-methyl-3-cyclohexen-1-yl) ) – 7.54 %, chamazulene – 5.32 %, alpha-bisabolol – 4.30 %, 1H-cycloprop[e]azulen-7-ol, decahydro-3,1,7-trimethyl-4-methylene – 3.25 %, myrtenyl acetate – 3.03 %, azulene, 1,2,3,3a,4,5,6,7-octahydro-1,4-dimethyl-7-(1-methylethenyl) – 2.16 %, bisabolol oxide B – 1.86 %. Commercial chamomile essential oil was dominated by 3-methoxy-3-methylbutanol (56.15 %), diethyl phthalate (17.46 %), linalyl acetate (6.99 %), linalool (4.41 %). Conclusions. Industrial cultivation of chamomile in southern Ukraine shows a high biologically active substances content and can be in demand in the pharmaceutical industry’s consumer market for raw materials.