Acetaldehyde Concentrations Research Articles

Comprehensive analysis of particulate matter, gaseous pollutants, and microbiological contamination in an international chain supermarket

Indoor environmental quality is of utmost importance since urban populations spend a large proportion of their life in confined spaces. Supermarkets offer a wide range of products and services that are prone to emitting several air pollutants. This study aimed to perform a comprehensive characterisation of the indoor and outdoor air quality in a multinational supermarket, encompassing not only criteria parameters but also unregulated pollutants of concern. Monitoring included measurements of comfort parameters, CO2, multiple gaseous pollutants, particulate matter (PM10) and bioburden. PM10, volatile organic compounds (VOCs) and carbonyls were subject to chemical speciation. Globally, the supermarket presented CO2, VOCs, and PM10 values below the limits imposed by international regulations. The PM10 concentration in the supermarket was 33.5±23.2 μg/m3, and the indoor-to-outdoor PM10 ratio was 1.76. Carbonaceous constituents represented PM10 mass fractions of 21.6% indoors and 15.3% outdoors. Due to the use of stainless-steel utensils, flour and fermentation processes, the bakery proved to be a pollution hotspot, presenting the highest concentrations of PM10 (73.1±9.16 μg/m3), PM10-bound elements (S, Cl, K, Ca, Ti, and Cr) and acetaldehyde (42.7 μg/m3). The maximum tetrachloroethylene level (130 μg/m3) was obtained in the cleaning products section. The highest values of colony-forming units of bacteria and fungi were recorded in the bakery, and fruit and vegetable section. The most prevalent fungal species was Penicillium sp., corresponding to 56.9% of the total colonies. In addition, other fungal species/sections with toxicological or pathogenic potential were detected (Aspergillus sections Aspergilli, Circumdati, Flavi, Mucor and Fusarium sp.).

Efficacy and Safety of Wilac L Probiotic Complex Isolated from Kimchi on the Regulation of Alcohol and Acetaldehyde Metabolism in Humans.

Alcohol-related hangovers impact both physical and mental wellness, largely due to acetaldehyde levels produced through alcohol metabolism. The present study investigated the efficacy and safety of the Wilac L probiotic complex (Levilactobacillus brevis WiKim0168 and Leuconostoc mesenteroides WiKim0172 isolated from kimchi) in improving hangovers post-alcohol consumption. This study was conducted as a randomized, double-blind, crossover placebo-controlled clinical trial from August 2023 to February 2024. Subjects (n = 26) were randomized into six test groups consuming three products, the Wilac L probiotic complex, Wilac L35 (Wilac L probiotic complex with Pyrus pyrifolia Nakai), or placebo, in different orders with crossover after a wash-out interval of 7-10 days. Blood alcohol and acetaldehyde concentrations were measured 0, 0.25, 0.5, 1, 2, 4, 6, and 15 h after alcohol consumption. The blood acetaldehyde levels measured with Wilac L probiotic complex supplementation were significantly lower than the control at 0.25 (p = 0.0381), 0.5 (p = 0.0498), and 1 h (p = 0.0260) post-consumption. The blood acetaldehyde levels after Wilac L35 consumption compared to the control are significant at 0.25 (p = 0.0115), 0.5 (p = 0.0054), 1 (p = 0.0285), 2 (p = 0.0113), and 6 h (p = 0.0287) post-consumption. No significant adverse events were reported. The Wilac L probiotic complex is associated with decreased blood acetaldehyde levels and improved subjective hangover symptoms.

Effects of GSH on Alcohol Metabolism and Hangover Improvement in Humans: A Randomized Double-Blind Placebo-Controlled Crossover Clinical Trial.

The definition of alcohol hangovers refers to a combination of mental and physical side effects that occur after drinking. One of the ways that hangovers can be ameliorated is by promoting the rapid and effective elimination of acetaldehyde to alleviate the discomfort it causes. This study aimed to investigate the effects of GSH (yeast extract containing 50 mg of glutathione) on the hangover-relieving effect. A randomized double-blind placebo-controlled crossover clinical trial was conducted with 40 participants who reported experiencing hangover symptoms. Participants consumed alcohol at a rate of 0.78 g per kg body weight with 40% whiskey, adjusted according to their weight. Alcohol and acetaldehyde concentrations in serum were analyzed at 0, 0.25, 1, 2, 4, 6, and 15 h after alcohol consumption. In the GSH group, the serum alcohol concentration decreased, although this change was not statistically significant. The serum acetaldehyde concentration was significantly lower in the GSH group in comparison to the placebo group (at 0.25, 1, 4, and 6 h (p < 0.01) and at 0.5, 2, and 15 h (p < 0.001) after alcohol consumption). However, there was no significant difference between the two groups on questionnaires such as the Acute Hangover Scale and the Alcohol Hangover Severity Scale. Overall, we consider the discovery that GSH lowered acetaldehyde concentration, a crucial factor in alcohol metabolism, to be more considerable. Therefore, GSH administration effectively reduces acetaldehyde levels in serum. This result suggests that this effect may contribute to the relief of hangover symptoms.

Design of Acetaldehyde Gas Sensor Based on Piezoelectric Multilayer Microelectromechanical System Resonator.

Acetaldehyde is a volatile organic compound that can cause damage at the cellular and genomic levels. The monitoring of acetaldehyde gas at low concentrations requires fast-response and low-cost sensors. Herein, we propose the design of an acetaldehyde gas sensor based on a low-cost Microelectromechanical System (MEMS) process. This sensor is formed by a single-clamped piezoelectric multilayer resonator (3000 × 1000 × 52.2 µm) with a simple operating principle and easy signal processing. This resonator uses a zinc oxide piezoelectric layer (1 µm thick) and a sensing film of titanium oxide (1 µm thick). In addition, the resonator uses a support layer of 304 stainless steel (50 µm thick) and two aluminum layers (100 nm thick). Analytical and Finite-Element Method (FEM) models are developed to predict the mechanical behavior of the gas sensor, considering the influence of the different layers of the resonator. The analytical results agree well with respect to the FEM model results. The gas sensor has a first bending frequency of 4722.4 Hz and a sensitivity of 8.22 kHz/g. A minimum detectable concentration of acetaldehyde of 102 ppm can be detected with the proposed sensor. This gas sensor has a linear behavior to detect different acetaldehyde concentrations using the frequency shifts of its multilayer resonator. The gas sensor design offers advantages such as small size, a light weight, and cost-efficient fabrication.

A Ratiometric Fluorescent Probe Dye-Functionalized MOFs Integrated with Logic Gate Operation for Efficient Detection of Acetaldehyde.

Volatile organic compounds (VOCs) are a class of hazardous gases that are widely present in the atmosphere and cause great harm to human health. In this paper, a ratiometric fluorescent probe (Dye@Eu-MOFs) based on a dye-functionalized metal-organic framework was designed to detect VOCs, which showed high sensitivity and specificity for acetaldehyde solution and vapor. A linear correlation between the integrated fluorescence intensity (I510/I616) and the concentration of acetaldehyde was investigated, enabling a quantitative analysis of acetaldehyde in the ranges of 1 × 10-4~10-5 μL/mL, with a low detection limit of 8.12 × 10-4 mg/L. The selective recognition of acetaldehyde could be clearly distinguished by the naked eye under the excitation of UV light. The potential sensing mechanism was also discussed. Significantly, a molecular logic gate was constructed based on the whole system, and finally, a molecular logic network system for acetaldehyde detection connecting basic and integrated logic operations was realized. This strategy provided an effective guiding method for constructing a molecular-level logic gate for acetaldehyde detection on a simple platform.

Copper (II) Level in Musts Affects Acetaldehyde Concentration, Phenolic Composition, and Chromatic Characteristics of Red and White Wines.

Copper (II), a vital fungicide in organic viticulture, also acts as a wine oxidation catalyst. However, limited data are currently available on the impact that maximum allowed copper (II) ion doses in wine grapes at harvest can have on aged wine quality. This was the focus of the present study. We investigated the copper (II) effects by producing both white and red wines from musts containing three initial metal concentrations according to the limits set for organic farming. In detail, the influence of copper (II) on fermentation evolution, chromatic characteristics, and phenolic compounds was evaluated. Interestingly, the white wine obtained with the highest permitted copper (II) dose initially exceeded the concentration of 1.0 mg/L at fermentation completion. However, after one year of storage, the copper (II) content fell below 0.2 ± 0.01 mg/L. Conversely, red wines showed copper (II) levels below 1.0 mg/L at the end of fermentation, but the initial copper (II) level in musts significantly affected total native anthocyanins, color intensity, hue, and acetaldehyde concentration. After 12-month aging, significant differences were observed in polymeric pigments, thus suggesting a potential long-term effect of copper (II) on red wine color stability.

Impact of pre- and post-fermentation fining with polyvinylpolypyrrolidone on the chemical stability and aromatic profile of Viognier wine.

Polyvinylpolypyrrolidone (PVPP) is a synthetic, insoluble polymer that can be added to white wines to improve the chemical stability of the final product by precipitating unstable low molecular weight phenolic compounds responsible for visual defects and undesirable flavor characteristics (e.g., excessive bitterness and/or astringency). The objective of this study was to characterize the effects of PVPP on the quality characteristics of Viognier wine when added pre- or post-fermentation as compared to an untreated control wine. Both PVPP-treated wines contained significantly lower concentrations of monomeric phenolics and browning pigments than the control wine (p≤0.05). The addition of PVPP prior to fermentation conferred protection against oxidation of the wine as measured by acetaldehyde concentration (p≤0.05). Analysis of the volatile aroma profile of each wine by headspace solid phase microextraction gas chromatographymass spectrometry (HS-SPME-GC-MS)revealed that the overarching aroma profiles of the PVPP-treated wines were significantly different from the control wine, but there was no difference between wines treated with PVPP pre-fermentation versus those treated post-fermentation. Specifically, statistically significant differences were observed in 9 of the 22 quantified aroma compounds, including those notably associated with the "stone fruit" aroma of Viognier. A negative correlation was identified between aroma compound concentration removal and the hydrophobicity of each compound, suggesting that the observed differences in aroma may be due to adsorption of aroma compounds by PVPP. The findings from this study present risks and benefits to wine quality upon treatment with PVPP at commercially recommended levels, and provide potentially valuable information for industrial wine producers.

VOC data-driven evaluation of vehicle cabin odor: from ANN to CNN-BiLSTM.

Emissions of volatile organic compounds (VOCs) in vehicles represent a significant problem, causing unpleasant odors. To mitigate VOCs and odors in vehicles, it is critical to choose interior parts with low odor and VOC emissions. However, prevailing odor evaluation methods are subjective, costly, and potentially harmful to the health of evaluators. In this study, we analyzed 139 automotive interior parts and 92 vehicles, establishing a cost-effective, data-driven method for odor evaluation. The contents of benzene, toluene, ethylbenzene, xylene, styrene, formaldehyde, acetaldehyde, acrolein, and total volatile organic compounds (TVOC) were detected by thermal desorption gas chromatography-mass spectrometry (TD-GC/MS) and high-performance liquid chromatography with an ultraviolet detector (HPLC-UV). Professional odor evaluators assessed the odors, identifying intensity levels from 2.0 to 4.5 in interior parts and 2.5 to 3.5 in whole vehicles. Leveraging this data, we applied four supervised learning algorithms to develop predictive models for the odor intensity of both interior parts and entire vehicles. During model training, we implemented early stopping techniques for the artificial neural network (ANN) and convolutional neural network-bidirectional long short-term memory (CNN-BiLSTM) models, while optimizing the support vector machine (SVM) and extreme gradient boosting (XGBoost) models using the GridSearch algorithm. The evaluation results reveal that the CNN-BiLSTM model performs the best, achieving an average accuracy of 89% for unknown samples within an odor intensity level of 0.5. The root mean square error (RMSE) is 0.24, and the mean absolute error (MAE) is 0.08. The model also underwent a sevenfold cross-validation, achieving an accuracy of 83.43%. Additionally, we employed SHapley Additive exPlanations (SHAP) for the interpretative analysis of the model, which confirmed the consistency of each VOC's odor contribution with human olfactory rules. By predicting odors based on VOCs through supervised learning, this study reduces the costs and enhances the efficiency and applicability of odor assessment across various vehicle interiors.

Novel kinetic modeling of photocatalytic degradation of ethanol and acetaldehyde in air by commercial and reduced ZnO: Effect of oxygen vacancies and humidity

A comprehensive kinetic model has been developed to address the factors and processes governing the photocatalytic removal of gaseous ethanol by using ZnO loaded in a prototype air purifier. This model simultaneously tracks the concentrations of ethanol and acetaldehyde (as its primary oxidation product) in both gas phase and on the catalyst surface. It accounts for reversible adsorption of both compounds to assign kinetic reaction parameters for different degradation pathways. The effects of oxygen vacancies on the catalyst have been validated through the comparative assessment on the catalytic performance of commercial ZnO before and after the reduction pre-treatment (10% H2/Ar gas at 500 °C). The influence of humidity has also been assessed by partitioning the concentrations of water molecules across the gas phase and catalyst surface interface. Given the significant impact of adsorption on photocatalytic processes, the beginning phases of all experiments (15 min in the dark) are integrated into the model. Results showcase a notable decrease in the adsorption removal of ethanol and acetaldehyde with an increase in relative humidity from 5% to 75%. The estimated number of active sites, as determined by the model, increases from 7.34 10−6 in commercial ZnO to 8.86 10−6 mol gcat−1 in reduced ZnO. Furthermore, the model predicts that the reaction occurs predominantly on the catalyst surface while only 14% in the gas phase. By using quantum yield calculations, the optimal humidity level for photocatalytic degradation is identified as 25% with the highest quantum yield of 6.98 10−3 (commercial ZnO) and 10.41 10−3 molecules photon−1 (reduced ZnO) catalysts.

Ethanol, acetaldehyde, and methanol in the gas phase and rainwater in different biomes and urban regions of Brazil

In the context of the increasing global use of ethanol biofuel, this work investigates the concentrations of ethanol, methanol, and acetaldehyde, in both the gaseous phase and rainwater, across six diverse urban regions and biomes in Brazil, a country where ethanol accounts for nearly half the light-duty vehicular fuel consumption. Atmospheric ethanol median concentrations in São Paulo (SP) (12.3 ± 12.1 ppbv) and Ribeirão Preto (RP) (12.1 ± 10.9 ppbv) were remarkably close, despite the SP vehicular fleet being ∼13 times larger. Likewise, the rainwater VWM ethanol concentration in SP (4.64 ± 0.38 μmol L−1) was only 26 % higher than in RP (3.42 ± 0.13 μmol L−1). This work demonstrated the importance of evaporative emissions, together with biomass burning, as sources of the compounds studied. The importance of biogenic emissions of methanol during forest flooding was identified in campaigns in the Amazon and Atlantic forests. Marine air masses arriving at a coastal site led to the lowest concentrations of ethanol measured in this work. Besides vehicular and biomass burning emissions, secondary formation of acetaldehyde by photochemical reactions may be relevant in urban and non-urban regions. The combined deposition flux of ethanol and methanol was 6.2 kg ha−1 year−1, avoiding oxidation to the corresponding and more toxic aldehydes. Considering the species determined here, the ozone formation potential (OFP) in RP was around two-fold higher than in SP, further evidencing the importance of emissions from regional distilleries and biomass burning, in addition to vehicles. At the forest and coastal sites, the OFP was approximately 5 times lower than at the urban sites. Our work evidenced that transition from gasoline to ethanol or ethanol blends brings the associated risk of increasing the concentrations of highly toxic aldehydes and ozone, potentially impacting the atmosphere and threatening air quality and human health in urban areas.

Heterogeneous nucleation optimization from AgCl and reduction control in ethylene glycol for fast and reproducible synthesis of silver nanowires

Silver nanowires synthesized by the most commonly used polyol method are typically accompanied by nanoparticles and nanorods, which have a negative impact on the performance of silver nanowire-based devices. Herein, we report a reproducible and easy method for preparing silver nanowires with yields exceeding 70% by optimizing the heterogeneous nucleation of silver from silver chloride precursors and regulating the reduction in ethylene glycol. The yield of silver nanowires depended on the morphology and concentration of silver chloride and the decomposition time of ethylene glycol. The Raman spectra were used to study the effect of the decomposition time of ethylene glycol on the concentration of acetaldehyde in solution, which influenced the reduction rate of silver ions. Then, the reaction time of silver nanowires was further reduced from 24 min to 10 min by increasing the reaction temperature from 160 °C to 170 °C. On the basis, the silver nanowire based capacitive screen with a good capacitive response and anti-aging performance was further fabricated. This method provides a new way for the macro preparation of silver nanowires with high yields.

Влияние винных и виноградных спиртов на качество напитков из виноградного сырья

Table grapes that have lost their marketable appearance are considered waste products. However, such grapes still possess some technological properties that make it possible to use them as a raw material for wine and grape spirits. This research featured the effect of the composition and technology of table grape alcohols on the volatile compounds and sensory profile &#x0D; of grape beverages.&#x0D; The study involved six white and six red grape beverages. In the test samples, the fermentation process was stopped by adding wine spirits and grape spirits obtained by rectification of distillates from table grapes. In the control samples, the procedure involved rectified grain alcohol. The physicochemical parameters of drinks and spirits were defined by standard methods. The highly volatile compounds were determined by gas chromatography. The sensory assessment was conducted by panelists from the Winemaking Research Center of the North-Caucasian Federal Scientific Center of Horticulture, Viticulture, and Winemaking.&#x0D; In this study, the wine spirits and the grape spirits obtained from table grapes had no effect on the standard indicators, e.g., volatile acids and acetoin. However, they increased the mass concentrations of highly volatile compounds in the following manner: drinks with grain alcohol ˂ drinks with wine alcohol ˂ drinks with grape alcohol. The content of acetaldehyde increased by 10–14% while the contents of ethyl acetate, esters, and higher alcohols increased by 25–35, 4.5–8.5, and 15%, respectively. The furfural content increased by 0.4–1.4 mg/L in the samples with grape alcohol. The samples with white grape varieties acquired a more prominent floral-honey flavor whereas those with black grapes acquired hints of hazelnut and honey.&#x0D; As a result of the study, it was found that wine alcohol and grape alcohol moderately increased the content of volatile compounds in drinks and had a positive effect on their sensory perception, which proves the expediency of their use in beverage technology.

Suppression of P2X4 and P2X7 by Lactobacillus rhamnosus vitaP1: effects on hangover symptoms

This study aimed to identify substances including Lactobacillus rhamnosus vitaP1 (KACC 92054P) that alleviate hangover-induced emotional anxiety and liver damage. The association between emotional anxiety caused by hangover and the genes P2X4, P2X7, SLC6A4 was investigated. In vitro and in vivo analyses were conducted to assess the influence of free-panica on alcohol-induced upregulated gene expression. Additionally, the concentration of AST, ALT, alcohol, and acetaldehyde in blood was measured. Free-panica, consisting of five natural products (Phyllanthus amarus, Phoenix dactylifera, Vitis vinifera, Zingiber officinale, and Lactobacillus rhamnosus), were evaluated for their regulatory effects on genes involved in alcohol-induced emotional anxiety and liver damage. The combination of these natural products in free-panica successfully restored emotional anxiety, and the concentration of AST, ALT, alcohol, and acetaldehyde in blood to those of the normal control group. These findings support the potential development of free-panica as a health functional food or medicinal intervention for relieving hangover symptoms and protecting liver from alcohol consumption.

VOC concentrations in houses in Japan: correlations with housing characteristics and types of ventilation

ABSTRACT Volatile organic compounds (VOCs) can cause health problems for residents and are one of the causes of sick building syndrome. Therefore, this study measured VOCs in 116 houses in the winter and 66 in the summer in Japan, including detached and apartment houses. The diffusion sampler method was used for field measurements. Living rooms and bedrooms were sampled to confirm the concentration characteristics and differences between the two locations. In addition, a questionnaire survey was conducted to identify the type of house, residence period, and type of ventilation system used. Most VOC concentrations did not exceed the Japanese guidelines during the winter and summer. However, in the winter, the acetaldehyde concentrations exceeded the Ministry of Health, Labour, and Welfare of Japan (MHLW) guidelines, reaching 14.7% in the living room and 12.9% in the bedroom. The VOC concentration was higher in apartments than in detached houses. Even among detached houses, built-for-sale houses had slightly higher VOC concentrations than custom-made houses. The concentration of VOCs according to characteristics, such as the residence period, did not show significant differences except for acetaldehyde. In houses with unbalanced ventilation, formaldehyde and other VOC concentrations were higher in the living room and bedroom than in houses with balanced ventilation.

Construction of 3D-graphene/NH2-MIL-125 nanohybrids via amino-ionic liquid dual-mode bonding for advanced acetaldehyde photodegradation under high humidity

The development of metal organic framework (MOF)-based π-π conjugated structures capable of effectively transforming H2O from humid air to •OH radicals for VOCs photodegradation is a significant but difficult task. Herein, an amino-ionic liquid (NH2-IL) based dual-mode bridging strategy was proposed to connect 3D-graphene with NH2-MIL-125 forming IL-3DGr/NM(Ti) nanohybrids for advanced acetaldehyde photodegradation. The rational integration of these components was responsible for: (1) maintaining π-π conjugated electron transport system; (2) generating abundant coordinatively unsaturated sites and oxygen vacancies; (3) increasing surface area of the nanohybrids. With these attributes, IL-3DGr/NM(Ti) demonstrated enhanced charge separation and transportation electrochemical impedance spectroscopy (EIS): 7-times), acetaldehyde adsorption (22 %), light absorption (bandgap: 1.51 eV). The rapid H2O adsorption and photoconversion to •OH radicals by IL-3DGr/NM(Ti) enabled it to demonstrate superior CH3CHO photodegradation rate under high humidity, surpassing many state-of-the-art photocatalysts by 9 to 187 times under static air conditions and with nearly similar catalyst dosages* (photocatalyst weight and initial acetaldehyde concentration (mg ppm−1) ratio). Interestingly, the IL-3DGr/NM(Ti) photocatalytic activity was enhanced by increasing RH% up-to 80 %. Besides, the nanohybrids demonstrated tremendous stability, with only a 3.9 % decline observed after 5 consecutive-cycles. This strategy provides new prospects to improve the compatibility of graphene/MOF materials for futuristic photoelectrical applications under high humidity.

Estimating the Anti-Viral Performance of Photocatalytic Materials: The Correlation between Air Purification Efficiency and Severe Acute Respiratory Syndrome Coronavirus 2 Inactivation

The coronavirus disease 2019 pandemic has increased the demand for anti-viral products. Photocatalytic materials are used to develop coatings and air purifiers that inactivate severe acute respiratory syndrome coronavirus 2. However, the methods for evaluating the anti-viral performance of photocatalytic materials are time-consuming. To address this problem, herein, we propose a screening test for the anti-viral performance of photocatalytic materials based on the ‘acetaldehyde decomposition test’—an air purification efficiency test used to evaluate the decomposition performance of photocatalytic materials. This test is suitable for screening multiple samples and conditions in a short period. The temporal variation in the acetaldehyde concentration was approximated using an exponential function, similar to the temporal variation in the viral infection values. Thereafter, the slope of the regression line for the acetaldehyde concentration over time was used as an indicator in the screening tests. When the anti-viral performance and acetaldehyde decomposition tests were conducted on the same photocatalytic material, a correlation was observed between the slopes of the regression lines. Overall, the proposed screening test shows good potential for evaluating the anti-viral performance of photocatalytic materials.

A primary study of ethanol production in postmortem liver and muscle tissue of rats

ObjectiveTo study the characteristics of postmortem ethanol production and its relation with alcohol congeners in postmortem rat liver and muscle tissues. MethodPostmortem liver and muscle tissues in Sprague–Dawley rats, from postmortem time interval (PMI) day 0–20, were analyzed via headspace gas chromatograph flame ionization detection to observe production of postmortem ethanol and 5 selected alcohol congeners. Result1. Putrid ethanol production increased gradually to a peak and then decreased with the prolongation of PMI; 2. Acetaldehyde, 1-propanol, and 3-methyl-butyraldehyde were produced along with postmortem ethanol; 1-butanol was only detected from day 11–20; 3. The concentrations of acetaldehyde, 1-propanol and 3-methyl-butyraldehyde was related with ethanol production. Fifteen mathematical models were constructed for putrid ethanol production based on acetaldehyde, 1-propanol, and 3-methyl-butyraldehyde. ConclusionA peak in postmortem ethanol production was identified. The production trends of acetaldehyde, 1-propanol, and 3-methyl-butyraldehyde in the liver, and of 1-propanol in muscle, were consistent with those of ethanol, and could potentially to be used as biomarkers of postmortem ethanol production. Further human samples and data analysis are needed to verify this.

Determination and Quantification of Acetaldehyde, Acetone, and Methanol in Hand Sanitizers Using Headspace GC/MS: Effect of Storage Time and Temperature.

Accurate determination of the concentration of alcohols and their metabolites is important in forensics and in several life science areas. A new headspace gas chromatography-mass spectrometry method has been developed to quantify alcohols and their oxidative products using isotope-labeled internal standards. The limit of detection (LOD) of the analytes in the developed method was 0.211 µg/mL for methanol, 0.158 µg/mL for ethanol, 0.157 µg/mL for isopropanol, 0.010 µg/mL for n-propanol, 0.157 µg/mL for acetone, and 0.209 µg/mL for acetaldehyde. The precision and accuracy of the method were evaluated, and the relative standard deviation percentages were found to be less than 3%. This work demonstrates the application of this method, specifically in quantifying the concentration of oxidative products of alcohol and other minor alcohols found in hand sanitizers, which have become an essential household item since the COVID-19 pandemic. Apart from the major components, the minor alcohols found in hand sanitizers include methanol, isopropanol, and n-propanol. The concentration range of these minor alcohols found in ethanol-based hand sanitizer samples was as follows: methanol, 0.000921-0.0151 mg/mL; isopropanol, 0.454-13.8 mg/mL; and n-propanol, 0.00474-0.152 mg/mL. In ethanol-based hand sanitizers, a significant amount of acetaldehyde (0.00623-0.231 mg/mL) was observed as an oxidation product, while in the isopropanol-based hand sanitizer, acetone (0.697 mg/mL) was observed as an oxidation product. The concentration of acetaldehyde in ethanol-based hand sanitizers significantly increased with storage time and temperature, whereas no such increase in acetone concentration was observed in isopropanol-based hand sanitizers with storage time and temperature. In two of the selected hand sanitizers, the acetaldehyde levels increased by almost 200% within a week when stored at room temperature. Additionally, exposing the hand sanitizers to a temperature of 45 °C for 24 h resulted in a 100% increase in acetaldehyde concentration. On the contrary, the acetone level remained constant upon the change in storage time and temperature.

ОПТИМИЗАЦИЯ УСЛОВИЙ СИНТЕЗА ПОЛИЭТИЛЕНТЕРЕФТАЛАТА И ВЛИЯНИЕ КАТАЛИЗАТОРОВ НА ЕГО СВОЙСТВА

In order to study the influence of the nature of the catalyst on the production process and the physicochemical properties of polyethylene terephthalate, samples were synthesized using catalysts based on antimony and titanium. Optimal catalyst concentrations were established for the production of polyethylene terephthalate with values close to those of industrial designs EKOPET samples: the characteristic viscosity (0.55-0.75 dl/g), melting temperature (max. 256°С), color number (L* ≥ 82.0; b * -1.5 ± 2.0) and acetaldehyde content (max. 1.0 ppm). The structure and properties of synthesized polyethylene terephthalate samples were studied using the methods of infrared spectroscopy and differential scanning calorimetry; transparency (L*) and color (b*) indicators, intrinsic viscosity, the amount of diethylene glycol, acetaldehyde and the content of terminal carboxyl groups were determined. Questions about the influence of nature, as well as the quantitative ratio of the catalyst on the indicators of color, transparency, intrinsic viscosity and the content of terminal carboxyl groups were discussed. It was revealed that titanium-containing compounds, in comparison with antimony catalysts, increase catalytic activity, which helps reduce the duration of the production process and produce polyethylene terephthalate with high molecular weight characteristics.

Determination of a robust headspace GC-MS/MS method for analysis of ethyl alcohol and acetaldehyde: clinical application to pharmacokinetics study.

Due to the forensic aspects of drinking and exposure to toxic substances, more sophisticated quantitative technology is needed to quantify the concentration of ethyl alcohol and acetaldehyde in the blood. In this study, we developed a headspace gas chromatography tandem mass spectrometry method that could simultaneously detect ethyl alcohol and acetaldehyde in human plasma. Through a simple preparation process, ethyl alcohol and acetaldehyde were quickly detected within 4 min, and a lower limit of quantification (LLOQ) (20 and 0.2 µg/mL) was obtained; these results confirmed the suitability of the system. According to Food and Drug Administration guidelines, the linearity (correlation coefficient > 0.9996), intraday and intraday accuracy, precision, and both short- and long-term stability and freeze-thaw stability satisfied the evaluation criteria (within 100.0 ± 15.0% and 20.0% of the LLOQ). Carryover and batch size assessment for the evaluation of the sample influence during analysis also satisfied the evaluation criteria. A valid method was applied to the pharmacokinetics study, and the plasma from 43 subjects after oral administration of the placebo or HK-GCM-H01 was analyzed. The developed analysis method for ethyl alcohol and acetaldehyde in blood could be used in various fields, such as forensics and those requiring precise quantification.