Mass Selective Detector Research Articles

Optimization of Odorous Compounds Analysis in Water Using Headspace-SPME and GC-MSD, and Detection Characteristics in the Nakdong River Basin

Objectives : This study developed a simple and automated analytical method using headspace-SPME (solid phase microextraction) and GC (gas chromatography)-MSD (mass selective detector) to simultaneously analyze ten odorous compounds (dimethyl trisulfide (DMTS), 3-hexenylacetate (HA), 2-isopropyl-3-methoxypyrazine (IPMP), 2-methylbenzofuran (MBF), 2-isobutyl-3-methoxypyrazine (IBMP), β-cyclocitral (CC), trans-2-decenal (DCNL), 2-trans-4-trans-decadienal (DENL) 2,4,6-trichloroanisole (TCA) 및 β-ionone (ION)), evaluating their distribution characteristics throughout the Nakdong River basin.Methods : To optimize the extraction efficiency of the headspace-SPME method for ten odorous compounds, we evaluated various SPME fiber materials, extraction temperatures, extraction times, desorption temperatures, desorption times and salt (NaCl) dosages. Additionally, using the optimized headspace-SPME, we investigated the detection concentrations at ten main stream sites and six tributary sites in the Nakdong River basin.Results and Discussion : The most suitable SPME fiber material for the pretreatment of ten odorous compounds was CAR/PDMS/DVB. The optimal SPME extraction temperature and time were 75°C and 60 minutes, respectively, and the optimal desorption temperature and time at the GC injection port were 250°C and 3 minutes. Additionally, the optimal salt (NaCl) dosage for a 10 mL water sample was 2 g. Using the optimized headspace-SPME pretreatment method for GC-MSD analysis, the detection limits and quantification limits for the ten odorous compounds ranged from 2 to 10 ng/L and 5 to 25 ng/L, respectively, with HA exhibiting the highest detection and quantification limits. The evaluation of the distribution characteristics of odorous compounds throughout the Nakdong River basin revealed that only three compounds—DMTS, CC and ION—were detected. Among these, DMTS was found at the highest concentration of 115.5 ng/L in the tributary Jincheon-cheon, while CC was detected at the highest concentration of 30.6 ng/L in the main river at Goryeong. In the case of the Nakdong River basin, there was no contamination by odorous compounds in the upstream area. In the middle reach, influenced by effluent of wastewater treatment plants, the detection concentrations of three odorous compounds increased, but they showed a decreasing trend as they moved downstream.Conclusion : Since odorous compounds can lead to distrust in water quality even at extremely low concentrations in the ng/L range in tap water, regular monitoring of water sources is necessary during algal bloom season, including the dry season. Furthermore, continuous research is needed on various odorous compounds beyond the 10 odorous compounds in this study, including the optimization of analytical methods and the detection characteristics in water sources.

Analysis of Extractives in Liquid and Headspace Samples of Silver Fir Using Gas Chromatography Coupled with a Mass Selective Detector

The main objective of the study is to present a chromatographic method that allows rapid and accurate quality control of extractives in liquid and headspace samples of wood and bark of European silver fir (Abies alba Mill.). The chemical identity of silver fir extractives in liquid and headspace samples was investigated. Mature silver firs were harvested and samples of sapwood, heartwood, knotwood and bark were prepared. Liquid samples were obtained by solvent extraction at higher temperature and pressure, while the volatile extractives of silver fir tissues were collected by headspace sampling. The extractives in the liquid silver fir samples were silylated prior to chromatographic analysis. The samples were then measured using gas chromatography (GC) coupled with a mass selective detector (MSD). The samples were introduced into the GC-MSD system using the Automatic Liquid Sampler (ALS) and the Headspace Sampler (HS). A total of 55 compounds were detected in the silver fir wood and bark samples. The liquid samples consisted of a variety of carboxylic/dicarboxylic acids, sugars with sugar alcohols (inositols) and sugar acids, with citric acid, quininic acid and sucrose being the most frequently represented. The liquid bark samples contained mainly sugar-like compounds, while the knotwood extracts contained large amounts of phenolic compounds and lignans. D-pitinol was confirmed as the most characteristic GC-MSD peak of the silver fir extracts. Analysis of the headspace of silver fir revealed α-pinene, camphene, Dlimonene, β-myrcene, ocimene, 2-bornanone or D-camphor and α-terpineol as the characteristic monoterpenes. It was shown that the presented GC-MSD method is a suitable analytical tool for the chemical screening of lowmolecular weight compounds in both liquid and headspace samples of wood and bark. However, the analysis of higher molecular weight extractives requires a different analytical approach supported by other analytical methods such as LC/MS.

Identification of flavonoids and hydroxycinnamic acids in polysaccharide-containing mixed herbal product (Pectorales species No 1) by Ultra-Performance Liquid Chromatography with Photodiode arrays and Tandem quadrupole Mass-selective detectors

Identification of flavonoids and hydroxycinnamic acids in polysaccharide-containing mixed herbal product (Pectorales species No 1) by Ultra-Performance Liquid Chromatography with Photodiode arrays and Tandem quadrupole Mass-selective detectors

Spatio-temporal distribution, source apportionment, ecological and human health risks assessment of polycyclic aromatic hydrocarbons in Sombreiro River Estuary, Niger Delta, Nigeria

ABSTRACT The spatio-temporal distribution, source apportionment, and risks of polycyclic aromatic hydrocarbon (PAHs) were investigated in the Sombreiro River Estuary, Niger Delta, Nigeria. Water, sediment and oysters were obtained from the estuary and analyzed for 16 priority PAHs using gas chromatograph coupled with mass selective detector after extraction. The levels of the ∑16-PAHs in the water, sediment and oyster ranged from 25-10079 µg/L, 495-12811 µg/kg and 489-10823 µg/kg respectively for all locations and seasons. The results showed significant spatio-temporal variations in PAHs concentrations in all the matrices. The ecological risk assessment revealed high risk posed by the PAHs level to the estuarine ecosystem. The health risk indicated unacceptable carcinogenic risk to human via ingestion of oysters. Besides, for water and sediments, both ingestion and dermal pathways indicated unacceptable cancer risk. Source apportionment suggested that the PAHs in the estuary were from both pyrogenic and petrogenic sources.

Detection of volatile organic compounds in soils (literature review)

Volatile organic compounds (VOC) are major environmental pollutants. Due to their high mobility, they penetrate into all environmental objects, pose an environmental threat and health risks. Getting into the soil, they deteriorate its quality. VOC content requires reliable control. There is presented a review of the literature, including methods of the US Environmental Protection Agency, and regulatory and methodological documents of the Russian Federation regulating methods of selection, storage, preparation and analysis of soil samples for VOC content. The dominant place among methods for monitoring for VOCs belongs to gas chromatography with various types of detectors. For multicomponent analysis of complex objects, gas chromatography with mass selective detection is used due to the wide capabilities provided by the mass detector. A universal mass spectrometry method used in analytical laboratories is electron impact ionization mass spectrometry. For research purposes, modern highly sensitive methods are used – mass spectrometry based on the proton transfer reaction PTR-MS, ion trap mass spectrometry PIT-MS, negative ion ionization mass spectrometry NI-PT-CIMS, time-of-flight mass spectrometry of the transfer reaction proton PTR-TOF-MS. The collection and storage of samples for VOC analysis requires compliance with regulations to prevent both loss of analytes and sample contamination. Sample preparation includes methods such as vacuum and azeotropic distillation, thermal desorption, liquid extraction, various options for static and dynamic headspace analysis.

Integrated approach to determining the identity of the pollution of adjacent territories with oil products

The methodology of arranging laboratory studies of oil-contaminated soils, soils and bottom sediments to determine the source and composition of hydrocarbon contamination is described. The complex approach to laboratory analysis of samples of oil-contaminated soils, soils and bottom sediments is proposed, which allows a highly reliable identification of the potential source of contamination and/or making conclusions about the identity of the contamination of adjacent territories. The proposed complex of analytical methods includes infrared spectrometry, gas chromatography with mass-selective detection, thin-layer chromatography with flame ionization detection and elemental analysis (C, H, N, S, O). Application of the proposed integrated approach allows highly reliable determination of the nature of oil contamination of soils, estimation of the total gross content of oil products and their hydrocarbon composition, and identification of the potential source of pollution. Possible errors in the interpretation of the results of determining the identity of contamination of territories and the importance of using an integrated approach in drawing conclusions about the source (culprit) of pollution are shown using real soil samples taken from oil-contaminated objects and adjacent territories. The importance of taking into account the losses of volatile oil products at the stage of sample preparation for soil contamination with light oil fractions is demonstrated. The use of standard methods of sample preparation (drying of the samples under study) leads to errors in assessing the level of contamination of territories with volatile hydrocarbons and in the choice of methods of remediation of contaminated territories. To minimize losses of volatile hydrocarbons (petrol and naphtha fractions) at the stage of soil sampling and transportation the use of sorbent is proposed. Addition of a sorbent to the soil contaminated with oil products can reduce losses of volatile hydrocarbons by 15 – 20% in the analyzed samples. Application of the developed complex approach makes it possible to determine the features of the individual hydrocarbon composition, group and elemental composition of petroleum products and identify hydrocarbon indicators (markers) inherent only to a certain type of petroleum product.

The Effect of the Extraction Conditions on the Antioxidant Activity and Bioactive Compounds Content in Ethanolic Extracts of Scutellaria baicalensis Root.

Ethanolic extracts of Baikal skullcap (Scutellaria baicalensis) root were obtained using various techniques, such as maceration, maceration with shaking, ultrasound-assisted extraction, reflux extraction, and Soxhlet extraction. The influence of the type and time of isolation technique on the extraction process was studied, and the quality of the obtained extracts was determined by spectrophotometric and chromatographic methods to find the optimal extraction conditions. Radical scavenging activity of the extracts was analyzed using DPPH assay, while total phenolic content (TPC) was analyzed by the method with the Folin-Ciocalteu reagent. Application of gas chromatography with mass selective detector (GC-MS) enabled the identification of some bioactive substances and a comparison of the composition of the particular extracts. The Baikal skullcap root extracts characterized by both the highest antioxidant activity and content of phenolic compounds were obtained in 2 h of reflux and Soxhlet extraction. The main biologically active compounds identified in extracts by the GC-MS method were wogonin and oroxylin A, known for their broad spectrum of biological effects, including antioxidant, anti-inflammatory, antiviral, anticancer, and others.

Chemical composition, antioxidant and antimicrobial activities of Rumex obtusifolius L. essential oil from the highlands of Ecuador

The chemical composition, antioxidant and antimicrobial activities of the essential oil from the aerial parts of Rumex obtusifolius L. were studied. To the best of the authors’ knowledge, this essential oil has never been fully characterized. The component analysis of the essential oil was done by gas chromatography with flame ionization detector (GC-FID) and mass selective detector (GC-MS). A total of 104 compounds, representing 97.8% of the essential oil, were identified. Aliphatic compounds, mainly methyl ketones (74.2%) and monoterpene hydrocarbons (13.7%) were found to be the most abundant compounds. The major compounds were undecan-2-one (47.6%) and nonan-2-one (13.4%). The antioxidant activity of the essential oil, evaluated by DPPH (IC50 9.11 mg/mL) and ABTS (IC50 36.72 mg/mL) assays, exhibited a weak ability in scavenging radicals. The essential oil also showed a low ferric reducing activity. The essential oil exhibited very good activity against E. coli and S. aureus, but low activities against S. enterica serovar, P. aeruginosa and C. albicans. MIC values of the essential oil varied from 0.38-27.04 μL/mL, with the lowest for E. coli.

ИССЛЕДОВАНИЕ ЭФИРНОГО МАСЛА ШИШЕК КЕДРОВОГО СТЛАНИКА (PINUS PUMILA (PALL.) REGEL)

Cedar elfin Pinus pumila (Pall.) Regel of the pine family – Pinaceae is a widespread plant in Eastern Siberia and the Russian Far East. Most studies of cedar elfin are devoted to the study of needles and woody greenery. Pine cones remain a poorly studied object, the chemical composition of which requires serious study to determine the prospects for further use. The aim of the work is to study the component composition and essential oil content in pine cones. To study the essential oil, samples of pine cones were harvested on the territory of the Magadan region, the Olsky urban district. The determination of the essential oil content in cones was carried out according to the methods of the State Pharmacopoeia of the XV edition. The component composition of the essential oil was determined using an Agilent 7890A gas chromatograph with a mass-selective detector. As a result of the study, it was found that a Clevenger device should be used to determine the content of essential oil in pine cones. The content of essential oil in cones is highest in July, slightly less in August, and in September there is no essential oil in the raw material. It has been established that July is the most favorable period for harvesting pine cones. The main component of the essential oil of pine cones is limonene. The proportion of the main component of the essential oil of pine cones, limonene, is higher in July, and the proportion of the undesirable component 3–karen increases in essential oil in August. The high content of limonene in the essential oil samples is a good prerequisite for further research and development of finished products.

Characterization and risk assessment of polycyclic aromatic hydrocarbons from the emission of different power generator

Epileptic power supply in Sub-Saharan countries of Africa has warranted the use of power generators as an alternative source of power supply. Exhaust emission from these generators is associated with Polycyclic Aromatic Hydrocarbon (PAHs). Hence, this study focused on the determination of levels of PAHs in the emission of different brands of power generators used in Nigeria. Exhaust emissions of different power generators were sampled using a filter-sorbent sampling system with polyurethane foam (PUF) as an adsorbent material. Analysis of PAHs was carried out using a Gas Chromatograph coupled to a mass selective detector (GC- MS) operated on Electron Ionization (EI) mode. The results showed the ∑ PAHs range 14.91–26.0 μgm−3. Bap was the most abundant of all the compounds with a concentration of 2.6 μgm−3 with a range of 2.08–3.07 μgm−3. The Incremental Life Cancer Risk (ILCR) values of all the generator's emission sampled are higher than 10− 4 for both children and adult which indicate a high potential cancer risk from inhalation of emission from these generators while Hazard Quotient (HQ) values from all the power generating set in this study are all above 1 which indicated high associated non-carcinogenic. The study revealed the levels of PAHs associated with the emission of power generators in Nigeria.

Nutritional Profiling of Underutilised Citrullus Lanatus Mucosospermus Seed Flour

The seed of Citrullus lanatus mucosospermus, known as egusi, is versatile and explored for its oil and flour functionality. Raw flour can be used as a raw material in a nutritional program due to its oil-rich, remarkably high protein content, and richness in omega-6 fatty acids. There is a need to explore eco-friendly defatting methods using the supercritical CO2 extraction method (SFECO2) to preserve this seed’s generic richness and to control the flour–oil ratio in processing formulations. The supercritical fluid extraction method uses temperature, pressure, and CO2 flow rate to determine the best yield and extraction parameters. Defatted egusi flour (DEF) was extracted using three runs. Firstly, at 60 °C, 30 g/h, and 450 bar (DEF1); secondly, at 55 °C, 30 g/h, and 600 bar (DEF2); and thirdly, extraction was performed at 75 °C, 30 g/h and 600 bar (DEF3). Trace and major elements were analysed using Agilent 7700 quadruple ICP-MS (Agilent Technologies Network, Palo Alto, CA, USA) and Thermo Cap 6200 ICP-AES (Thermo Scientific, Waltham, MA, USA), respectively. The sugar was separated on a gas chromatograph coupled to a Mass Selective Detector (MSD). The fundamental pasting property measurements were performed using a Rapid Visco Analyser RVA 4500 Perten instrument Sin 214 31208-45 Australia. Data analysis was conducted using IBM SPSS version 29 software (v. 2022). The protein content of defatted egusi flour ranged from 48.4 for DEF2 to 60.4% w/w for DEF1 and differed significantly, with a rich amino acid high in glutamine ranging from 9.8 to 12.9 g/100 g). DEF2 (512.0 cP) showed the highest peak viscosity and was the most viscous among the samples. Defatted flour with lower temperature and lower pressure (60 °C and 450 bar) offered the best nutritional properties, proffering defatted egusi flour from SFECO2, a novel flour for dietary programs.

Characterization of polycyclic aromatic hydrocarbons in mangrove sediments from Ifiekporo Creek, Warri, Nigeria

The occurrence and level of polycyclic aromatic hydrocarbons (PAHs) in mangrove sediment from Ifiekporo Creek in Warri, Delta State, Nigeria, were assessed in this study. The extraction of PAHs from the sediment samples was achieved using the PAH analytical test method (USEPA 8270). This method measures the individual concentrations of extractable PAHs in samples. The PAHs were quantified within the C11-C22 subgroup. The basic GC parameters for the analysis of polyaromatic hydrocarbons were analysed using a gas chromatography‒mass selective detector (GC‒MSD). The individual PAH concentrations in the mangrove sediment samples ranged from 850 µg/kg−1 to 3470 µg/kg−1. PAH source apportionment employing isomeric ratios and multivariate statistics indicated both pyrogenic and petrogenic source inputs in the sediment samples. The order of PAH homology in the sediment was 3-ring > 2-ring > 4-ring. The sediment samples were mostly dominated by LMW PAHs. The results of the ecological risk assessment in the study area indicate that there is low ecological risk associated with PAH exposure in sediment. These results provide data on the concentrations and compositional patterns of PAHs, which is useful for understanding the effects, sources, fates, and transport of PAHs in sediment in the study area, as well as for providing relevant information for environmental quality management and forensic studies.

Development and validation of a method for the quantitative determination of metoprolol succinate in the air of the working area by high-performance liquid chromatography using mass spectra

Introduction. Metoprolol is a cardioselective blocker of β-adrenergic receptors. Drugs containing metoprolol have hypotensive, antianginal, antiarrhythmic effects. Moderately dangerous when taken orally, has a general toxic effect. Metoprolol is produced in two forms: in the form of salts of tartaric and succinic acids, the approximate safe level of exposure to which is 0.3 mg/m3. To ensure the safety of workers, it is necessary to carry out sanitary and hygienic air control. Methods for the quantitative analysis of metoprolol in the air of the working area, presented in the current scientific literature, allow monitoring only for metoprolol salts in the form of tartrate. 
 The aim of the study is to develop and validate an analytical method for the quantitative determination 
 of metoprolol succinate in the air of the working area by HPLC-MS. 
 Materials and methods. For the analysis, standard samples of metoprolol succinate and air samples taken at all stages of the life cycle of the production of the drug metoproolol were used. Chromatographic separation and detection were performed on an Agilent 1260 Infinity G6125B high performance liquid chromatograph (Agilent Technologies, USA) equipped with a column and sample thermostat, a degasser, a pump, an autosampler, and a G6125B mass selective detector. A Waters Xbridge® C18 3.5 µm column was used; 2.1×30 mm (Waters, Ireland). Primary data were processed using Open Lab CDS ChemStation Edition (Rev. C.01.07 SR3) software (Agilent Technologies, USA).
 Results. A method for the quantitative determination of metoprolol succinate in air samples by HPLC-MS has been developed and validated. During the validation of the developed methodology, it was found that the validation characteristics (specificity, linearity, accuracy and precision, correctness, reproducibility) are within the acceptance criteria. The analytical range of the technique was 0.1–10.0 µg/ml and allows the developed technique to be used to control the average shift MPCs in the air of the working area.
 Limitations. The results of the study of the air in the working area are applicable only to the production of the drug metoprolol in the form of tablets; the study of air during the synthesis and packaging of the active pharmaceutical substance was not carried out. 
 Conclusion. An analysis of air samples from the production of the drug metoprolol was carried out and the safety of working conditions was proved.

Development and Validation of an HPLC-MS/MS Method for Quantification of Apixaban in Human Plasma

Introduction. Apixaban is an anticoagulant used in a number of thromboembolic diseases with an improved benefit-to-risk ratio, according to multiple clinical studies. Due to the prescription of apixaban as antithrombotic therapy in patients with COVID-19, an increase in its use has been observed. Thus, due to the widespread use of apixaban and the need to conduct pharmacokinetic and bioequivalence studies of the drug, it is important to develop and validate a simple and sensitive method for the quantitative determination of apixaban in human blood plasma.Aim. The aim of the study is to develop and validate a method for the determination of apixaban in human blood plasma using high-performance liquid chromatography with tandem mass selective detection (HPLC-MS/MS) for the subsequent bioanalytical study.Materials and methods. The determination of apixaban in human plasma was carried out by HPLC-MS/MS with rivaroxaban as an internal standard. The method of protein precipitation with acetonitrile was used as sample preparation. Mobile phase: 0.1 % solution of formic acid in water (eluent A); 0.1 % solution of formic acid in acetonitrile (eluent B). The total run time was 3.00 min. Column: Shim-pack Velox Biphenyl; 2.7 µm; 50 × 2.1 mm. Ionization source: electrospray with positive ionization mode. MRM transitions: 460.15 → 443.10 m/z (apixaban); 436.05 → 144.95 m/z (rivaroxaban).Results and discussion. The developed method was validated in accordance with the EAEU requirements for the following parameters: selectivity, calibration curve, accuracy and precision, lower limit of quantitation, suitability of standard samples, matrix effect, recovery, stability, carry-over, dilution effects. The parameters met the acceptance criteria.Conclusion. The confirmed analytical range of the developed and validated method was 1.00–300.00 ng/mL in blood plasma. The method for determining apixaban in blood plasma is simple and sensitive. This method was tested during the analytical part of the bioanalytical study and can be used to conduct other pharmacokinetic studies of apixaban drugs.

Antimicrobial Activity of Citrate-Coated Cerium Oxide Nanoparticles.

The purpose of this study was to investigate the antimicrobial activity of citrate-stabilized sols of cerium oxide nanoparticles at different concentrations via different microbiological methods and to compare the effect with the peroxidase activity of nanoceria for the subsequent development of a regeneration-stimulating medical and/or veterinary wound-healing product providing new types of antimicrobial action. The object of this study was cerium oxide nanoparticles synthesized from aqueous solutions of cerium (III) nitrate hexahydrate and citric acid (the size of the nanoparticles was 3-5 nm, and their aggregates were 60-130 nm). Nanoceria oxide sols with a wide range of concentrations (10-1-10-6 M) as well as powder (the dry substance) were used. Both bacterial and fungal strains (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Proteus vulgaris, Candida albicans, Aspergillus brasielensis) were used for the microbiological studies. The antimicrobial activity of nanoceria was investigated across a wide range of concentrations using three methods sequentially; the antimicrobial activity was studied by examining diffusion into agar, the serial dilution method was used to detect the minimum inhibitory and bactericidal concentrations, and, finally, gas chromatography with mass-selective detection was performed to study the inhibition of E. coli's growth. To study the redox activity of different concentrations of nanocerium, we studied the intensity of chemiluminescence in the oxidation reaction of luminol in the presence of hydrogen peroxide. As a result of this study's use of the agar diffusion and serial dilution methods followed by sowing, no significant evidence of antimicrobial activity was found. At the same time, in the current study of antimicrobial activity against E. coli strains using gas chromatography with mass spectrometry, the ability of nanoceria to significantly inhibit the growth and reproduction of microorganisms after 24 h and, in particular, after 48 h of incubation at a wide range of concentrations, 10-2-10-5 M (48-95% reduction in the number of microbes with a significant dose-dependent effect) was determined as the optimum concentration. A reliable redox activity of nanoceria coated with citrate was established, increasing in proportion to the concentration, confirming the oxidative mechanism of the action of nanoceria. Thus, nanoceria have a dose-dependent bacteriostatic effect, which is most pronounced at concentrations of 10-2-10-3 M. Unlike the effects of classical antiseptics, the effect was manifested from 2 days and increased during the observation. To study the antimicrobial activity of nanomaterials, it is advisable not to use classical qualitative and semi-quantitative methods; rather, the employment of more accurate quantitative methods is advised, in particular, gas chromatography-mass spectrometry, during several days of incubation.

Levels of polycyclic aromatic hydrocarbon in the soil around typical automobile repair workshops in Nigeria.

This study determined the levels of polycyclic aromatic hydrocarbons (PAHs) in the soil around typical automobile repair workshops in Nigeria. Risk assessment associated with human contact with the soil was carried out using hazard quotient (HQ) and incremental life cancer risk (ILCR) from human unconscious ingestion and dermal contact with the soil. Soil samples were obtained at different automobile workshops in Ado-Ekiti, Western Nigeria. The PAHS in the samples were extracted using dichloromethane and extracts were cleaned up using silica-alumina gel open column chromatography. Analysis of PAHs in the soil was done using a gas chromatograph coupled to a mass selective detector operated on electron ionization mode. The results showed the mean PAHs concentration at the sampling locations ranged from 5.58 - 6.4 μg/g and the mean ∑ carcinogenic PAHs was 58.4 μg/g, equivalent to 59.39 % of total PAHs observed. The mean Toxicity equivalence (TEQs) ranged from 0.02 - 6.680 μg/g. Benzo (a) pyrene and dibenzo(a,h)anthracene have the highest toxicity equivalent. The total ILCRs from accidental ingestion and dermal contact in adults were 1 ×10^(-3) and 9.8 ×10^(-5), for adults and children respectively; both are higher than the permissible limit stipulated by the World Health Organization.The HQs obtained are several folds higher than 1. This implies high carcinogenic and non-carcinogenic risks for children and adults. The study revealed the levels of PAHs and also revealed the risks associated with human contact with the soil around automobile repair workshops.

Antimicrobial Activity of Selected Essential Oils against Staphylococcus aureus from Bovine Mastitis

Staphylococcus aureus is a major cause of subclinical mastitis in dairy cows, and its development of antibiotic resistance has limited treatment efficacy. Essential oils (EOs) are natural products with a wide range of antimicrobial properties that could be used to treat bovine mastitis. This study aims to investigate the antimicrobial activity of EOs against S. aureus isolated from subclinical bovine mastitis cases in the State of São Paulo—Brazil. A total of 14 S. aureus isolates were selected, based on the presence of biofilm-forming genes (icaA, icaD, and bap), and were cultured to a final concentration of 103 CFU.mL−1 for the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) analysis of five EOs (Citrus aurantium bergamia—bergamot, Copaifera reticulata—copaiba, Foeniculum vulgare—fennel, Zingiber officinale—ginger, and Ocimum basilicum—basil). The chemical compositions of the EOs were characterized using gas chromatography coupled with a mass-selective detector (GC/MSD). Basil and bergamot EOs exhibited the highest antimicrobial activity against S. aureus strains, with mean MIC/MBC values of 1.561 ± 0.223/2.806 ± 0.255 mg.mL−1 and 2.782 ± 0.228/4.396 ± 0.198 mg.mL−1, respectively. The primary compounds in basil EO were methyl-chavicol, linalool, and α-humulene, while bergamot EO predominantly contained linalyl acetate, limonene, and linalool. This research highlights the potential of basil and bergamot EOs as natural antimicrobial agents for treating bovine mastitis caused by S. aureus, offering a potential alternative to traditional antibiotics and contributing to animal welfare and public health. In addition, it emphasizes the need for further studies to validate the long-term effects, optimal dosages, and application methods.

Profile change of the volatile and non-volatile compounds in dried or baked laver by photooxidation.

Effects of light or dark storage condition on the profile changes of volatile and non-volatile compounds were evaluated in dried and baked laver for 60 days. Volatile and non-volatile compounds were analyzed using gas chromatography-mass selective detection and high-performance liquid chromatography-quadrupole-time of flight-mass spectrometry, respectively. Baked laver stored in light conditions for 60 days produced the most volatile compounds, whereas dried laver stored in the dark produced the least volatile compounds. Total 11 classes of volatile compounds were detected, including alkanes, alkenes, and ketones, with aldehydes being most abundant in dried laver stored under light. Metabolite analysis of non-volatile compounds led to the selection of 12 compounds with a higher variable importance projection (VIP) value of >1.0: 6 fatty acids (VIP 1.2-2.0), 2 flavanols (VIP 1.3-1.8), hydroxybenzoic acid (VIP 1.5), hydroxycinnamic acid (VIP 2.3), a phenolic acid ester (VIP 1.9), and phloroglucinol (VIP 1.2). Generally, levels of these compounds decreased more following storage in the light than under dark, irrespective of laver preparation. The content of linolenic acid was particularly affected by storage conditions, with light conditions causing a fourfold reduction in linolenic acid level compared with dark conditions, which could result in an increased formation of aldehydes. Gallic acid and sinapinic acid were detected in dried but not baked laver, as they are destroyed by heat treatment. Therefore, laver should be baked and stored in dark conditions to prevent the development of rancidity. PRACTICAL APPLICATION: Laver is one of the representative seaweeds, and the popularity among consumers increases. Although commercially available laver is prepared in dried or baked condition, scientific studies on the changes of metabolites, including volatile and non-volatile compounds during storage, are scarce. The results of this study can be applied to improve proper storage methods to maintain the quality of laver, which can be beneficial for consumers and food industry.

Hepatoprotective Activity of Pine cones Extract

Introduction. Fatty hepatosis is a widespread metabolic disease. There is an annual increase in cases of detection of fatty hepatosis both in Russia and around the world. An urgent task is to search for new medicines for the treatment and prevention of the development of fatty hepatosis.Aim. Investigation of the composition of procyanidins and the biological activity of pine cones extract on a model of fatty hepatosis in vivo.Materials and methods. To obtain the extract, cones of pine harvested on the territory of the Perm Region in December were used. The extract was obtained by processing raw materials with hot water. The component composition of procyanidins in the extract was determined using ultra-efficient liquid chromatography with a mass selective detector. Hepatoprotective activity was studied on a model of fatty hepatosis induced by the introduction of carbon tetrachloride in vivo on white mongrel rats. Silymarin was used as a reference for comparison.Results and discussion. As a result of chromatographic examination, the following procyanidins were identified in a dry aqueous extract of pine cones – B2, B3, C1, C2, D1. As a result of hepatoprotective activity, it was found that no changes were detected in the control (intact) group during the pathohistological examination of the liver. Index (degree) of steatosis: 0. In the experimental group, whose animals were injected with carbon tetrachloride without subsequent treatment, it was found that about 50 % of hepatocytes of the histological section were in a state of macro- and microvesicular fatty dystrophy. The steatosis index is 2. In the group of animals injected with carbon tetrachloride and treated with Karsil®, normalsized hepatocytes with single fatty microvesicles in the cytoplasm. The steatosis index is 0. In the group of animals injected with carbon tetrachloride and treated with pine cones extract, hepatocytes of normal size with an euchromic nucleus, in the central parts in a state of macro- and microvesicular fatty dystrophy (about 20-25 % of all hepatocytes of the histological section). The steatosis index is 1.Conclusion. The extract of pine cones contributes to a moderate decrease in the prevalence of protein, small-focal small-droplet fatty dystrophy of hepatocytes. To increase hepatoprotective activity, it is necessary to investigate the effect of the extract at a dose of 30 mg/kg and above.

Phenological Fluctuations of Secondary Metabolites in Dracocephalum charkeviczii

Plants from the genus Dracocephalum are a source of biologically active compounds, including rosmarinic acid and different flavonoids. Their concentration varies during the vegetation period. In order to examine changes in their content in Dracocephalum charkeviczii Prob., an endemic species of Sikhote Alin and South Kuriles, wild and cultivated plants were collected in three phenological stages: vegetation, flowering/start of fructification, and preparation for withering. By means of HPLC with UV and mass selective detection, 15 polyphenol compounds were detected in methanol extracts from the leaves. Several new compounds—coumaric acid glycoside, quercetin glycoside and rutinoside, and acacetin coumaroylglycoside—were identified in D. charkeviczii. Synthesis of most flavonoids was found to be the highest in the beginning of the vegetation period, and gradually decreased by its end. The concentration of caffeic acid derivatives (chlorogenic acid, rosmarinic acid glycoside, and dehydrorhabdosiin) increased, but the total concentration of compounds decreased by the end of vegetation.