Use Of Correction Factors Research Articles

Temporal and spatial variability in availability bias has consequences for marine bird abundance estimates during the non‐breeding season

Abstract To effectively monitor how marine ecosystems are being reshaped by anthropogenic pressures, we require understanding of species abundances and distributions. Due to their socio‐economic and ecological value, predatory species are often at the forefront of survey efforts. However, survey data are only valuable if they can reliably be converted into estimates of underlying distributions. We consider at‐sea surveys of marine predators that often inform ecological impact assessments of offshore windfarms. These surveys are subject to a form of detection bias called ‘availability bias’ whereby individuals which are submerged below the surface are consequently ‘unavailable’ for detection. Although correction factors are commonly used in these surveys, they are currently based on limited data that may not be species‐, time‐, or area‐specific. Here, we use time‐depth‐recorder data to investigate variation in marine bird availability bias. We found that the proportion of diving marine birds submerged below the sea surface during daylight hours, and therefore unavailable to be counted during surveys, varied by species, month, and area. For three of our focal species wintering around northwest Europe (Atlantic puffin, common guillemot, razorbill), our results were different to comparable values previously used to correct for the availability bias, whereas no correction factors are regularly used for the fourth species (red‐throated diver). We now present availability bias correction factors that are species‐ and month‐specific to the areas the study populations use during their non‐breeding seasons: the North Sea, the north and west coasts of the UK, the Baltic Sea, and Icelandic coastal waters. Practical implication: Variation in the proportion of daylight hours that marine birds spent submerged lead to differences in availability bias correction factors, thereby impacting estimations of their abundances. We encourage use of correction factors that use data from the species, marine area, and month during which surveys are conducted to provide more accurate abundance estimates. Using more relevant correction factors will result in increasingly accurate abundance and distribution estimates of diving marine birds, with relevance for a range of applications including planning for offshore windfarm developments, the designation and monitoring of protected areas, and understanding environmental change.

Versatile ferrous oxidation-xylenol orange assay for high-throughput screening of lipoxygenase activity.

Lipoxygenases (LOXs) catalyze dioxygenation of polyunsaturated fatty acids (PUFAs) into fatty acid hydroperoxides (FAHPs), which can be further transformed into a number of value-added compounds. LOXs have garnered interest as biocatalysts for various industrial applications. Therefore, a high-throughput LOX activity assay is essential to evaluate their performance under different conditions. This study aimed to enhance the suitability of the ferrous-oxidized xylenol orange (FOX) assay for screening LOX activity across a wide pH range with different PUFAs. The narrow linear detection range of the standard FOX assay restricts its utility in screening LOX activity. To address this, the concentration of perchloric acid in the xylenol orange reagent was adjusted. The modified assay exhibited a fivefold expansion in the linear detection range for hydroperoxides and accommodated samples with pH values ranging from 3 to 10. The assay could quantify various hydroperoxide species, indicating its applicability in assessing LOX substrate preferences. Due to sensitivity to pH, buffer types, and hydroperoxide species, the assay required calibration using the respective standard compound diluted in the same buffer as the measured sample. The use of correction factors is suggested when financial constraints limit the use of FAHP standard compounds in routine LOX substrate preference analysis. FAHP quantification by the modified FOX assay aligned well with results obtained using the commonly used conjugated diene method, while offering a quicker and broader sample pH range assessment. Thus, the modified FOX assay can be used as a reliable high-throughput screening method for determining LOX activity. KEY POINTS: • Modifying perchloric acid level in FOX reagent expands its linear detection range • The modified FOX assay is applicable for screening LOX activity in a wide pH range • The modified FOX assay effectively assesses substrate specificity of LOX.

Calculation of EPD for individual AAC product classes

AbstractIn fact, climate change is increasing the relevance of Environmental Product Declarations (EPDs). Currently, product‐specific EPDs are coming into vogue instead of average‐based EPDs. Individual EPDs for distinct products can be beneficial, but the data preparation upfront is crucial to avoid greenwashing through the use of false data. Adjustments to the standards for calculating EPDs are currently under development.The starting point for the calculation of EPD according to EN 15804+A2 is always the annual production and associated consumption of raw materials and energy. The raw material input per product is calculated from recipe data and the respective production quantities as a first step. This shall be done for all products of a plant. Now, the summarized consumptions have to be related with the purchased raw material quantities, correction factors have to be calculated and applied to specify the actual input per product. The use of correction factors is mandatory to avoid inaccuracy and underestimation of actual consumption. Hence, the calculation of one product‐specific EPD requires product‐specific source data preparation for all products.In AAC production, the correction of the consumed raw materials is particularly important concerning internal recycling. For example, the actual consumption of aluminum is of specific interest. While ground sand within the recycled sludge is unchanged and binders still react in the autoclave, the aluminum is no longer reactive. This can lead to additional aluminum consumption that deviates by one‐third and more from the recipe values.In the presentation, a comprehensive approach to the calculation of correction factors for different AAC product classes will be introduced. The final calculations for the EPD are not based on recipe data alone but are corrected using procurement data. Thus, the total consumption of a plant can be adequately allocated to all products in the production program.

Small field output correction factors at 18MV.

The response of various detectors in the radiotherapy energy range has been investigated, especially for 6 and 10MV energies for small fields, and is summarized in TRS-483. However, data for accelerator energies above 10MV are sparse or unavailable for many detectors, especially for the energy of 18MV. Small variations in field output factors for the commissioning of a treatment planning system can have a high impact on calculation of dosedistributions. Many studies describe an energy dependence of the response for a large number of detectors. We wanted to close the gap for the 18MV energy regime and determined field output correction factors for different detectors at18MV. An ELEKTA Versa HD accelerator at 18MV was used together with a PTW MP3 water phantom at an SSD of 90cm. The following detectors were examined: PTW Semiflex 31021, PinPoint 3D 31022, diode 60012, diode 60008 and microDiamond 60019, Sun Nuclear EDGE detector, IBA PFD, SFD, Razor Chamber, Razor Nano Chamber and Razor Diode, Standard Imaging Scintillator Exradin W2 1x3, W2 1x1 and Gafchromic EBT3 film. The dose response was determined at a depth of 10cm for square fields between 0.5 and 10cm side length. As reference data a composure of radiochromic film data for small fields ( cm) and data of all compatible chambers for larger fields ( cm) was used. The effective field sizes of small fields were determined from profiles obtained on radiochromic film. The obtained field output correction factors obey the rules of the TRS-483protocol. The W2 1x1 scintillator and the Razor Chamber showed the smallest deviations from the reference curve. The shielded diodes (diode 60008, EDGE detector) showed the highest over-response at small fields, followed by PFD, microDiamond and the unshielded diodes (diode 60012, SFD). The ionization chambers exhibited the well-known volume effect, that is, strong under-response at small fields of up to 9% for the PinPoint 3D, 7% for the Razor Chamber and up to 30% for the Semiflex detector for the smallest studied field size. The small chambers showed a polarity effect in axial orientation, especially the Razor Nano Chamber. Corrections at 18 MV are generally larger than those provided by TRS-483, continuing the trend of increasing corrections between 6 and 10 MV also at a higher accelerator energy. Only the PinPoint 3D Chamber showed a slightly smallercorrection. Field output correction factors were determined for square field sizes between 0.5 and 10cm at 18MV. Most detectors needed a larger correction than at 6 and 10MV. Thus, the use of correction factors will improve beam data for18MV.

An Accurate Approach for Computational pKa Determination of Phenolic Compounds

Computational chemistry is a valuable tool, as it allows for in silico prediction of key parameters of novel compounds, such as pKa. In the framework of computational pKa determination, the literature offers several approaches based on different level of theories, functionals and continuum solvation models. However, correction factors are often used to provide reliable models that adequately predict pKa. In this work, an accurate protocol based on a direct approach is proposed for computing phenols pKa. Importantly, this methodology does not require the use of correction factors or mathematical fitting, making it highly practical, easy to use and fast. Above all, DFT calculations performed in the presence two explicit water molecules using CAM-B3LYP functional with 6-311G+dp basis set and a solvation model based on density (SMD) led to accurate pKa values. In particular, calculations performed on a series of 13 differently substituted phenols provided reliable results, with a mean absolute error of 0.3. Furthermore, the model achieves accurate results with -CN and -NO2 substituents, which are usually excluded from computational pKa studies, enabling easy and reliable pKa determination in a wide range of phenols.

An advanced, comprehensive thermochemical equilibrium model of a downdraft biomass gasifier

A stoichiometric model is formulated for predicting the syngas yield from the reduction zone of a downdraft biomass gasifier. It incorporates the thermodynamic equilibrium of the global gasification reaction, predicts the concentration of the minor gasification products of hydrogen sulphide and ammonia as the sulphur-based and nitrogen-based contaminants, respectively, and implements a new empirical correlation, formulated using existing pertinent experimental data, to account for the mass tar yield. The governing set of model equations is solved in a fully coupled manner, with the boudouard reaction employed to predict char output and the ammonia synthesis reaction used to predict ammonia production. The model does not require the use of correction factors and satisfactorily predicts the concentration of methane, a shortcoming that has tended to plague existing equilibrium models. The syngas composition, tar and char yields, gasification temperature, cold gas efficiency and lower heating value are obtained for various biomass feedstock with a specific ultimate analysis, for different equivalence ratios and varying moisture content. Where possible, predictions are compared with corresponding experimental data and found to be in very good agreement.

Calculation of the effective mechanical characteristics of the undermined rock mass

An approach has been developed to construct functional expressions for calculating the effective mechanical characteristics of the undermined rock massif during its repeated mining, taking into account the disturbance of the different-type massif continuity and the time passed after the undermining. The approach was developed as applied to the conditions of the Starobin potash salt deposit. It is based on introducing special correction factors into the expressions for mechanical characteristics of the massif. At the same time, the state of the undermined massif area is considered in the continuum model approximation. It is shown that one of the most important factors to be considered when constructing the functional dependence for mechanical characteristics of the undermined layered massif is to take into account the mutual slippage of layers and their lamination related to it, because the strength characteristics such as bonding strength and internal friction coefficient mainly change when the massif is undermined. The algorithm for calculating the mechanical properties of the undermined massif proposes the use of correction factors that take into account the heterogeneity of the rock massif; lamination and slippage of the contacting layers; changes in the properties of the undermined massif with variation of the depth of repeated mining; changes in the properties resulting from the technological disturbance of the massif initial equilibrium state (primary undermining, time passed since the primary undermining).

Economic and mathematical modeling of long-term development of national industry in the conditions of digitalization with the use of a production function

The article substantiates the expediency of modeling the development of national industry taking into account how the main interconnected key sectors of Ukrainian economy (not only processing and extractive industries, but also agriculture) are developing, as well as taking into account the factors that cause changes in this development over time. Based on previous researches, multiplicative production function has been chosen as the base for building the model, which was modified by taking into account the peculiarities of the Fourth Industrial Revolution and the specifics of individual industries in Ukraine. The economic-mathematical model of long-term development of specified branches of economy of Ukraine in the conditions of digitalization was proposed, in which the value added in the branch is the dependent variable, and the classic components of production functions (labor and the capital) are the independent variables, as well as the new factor – digitalization, and factors, specific to individual industries (world food price index for agriculture and world raw material price index for the extractive industry). A specific feature of the model is also the use of correction factors that reflect the change in the return of factors over time and increase the accuracy of calculations. In addition, separate models have been developed to calculate each of the main factors, based on the dynamics of investments, taking into account the recursive influence of value added, propensity to invest, the condition of the world economy and other specific factors. The calculation of value added in agriculture, extractive and processing industries of Ukraine in 2010-2019 was performed using the model. The adequacy of the model was validated based on the results of its parameterization, which showed sufficient accuracy for the implementation on practice, as the average absolute error of approximation ranges from 2.94% to 4.14% depending on the industry, with abnormal 2014-2015 excluded from the calculations. The value of GDP in the country as a whole was calculated on the basis of the results of value added calculations by key industries. Taking into account the fact that the proposed set of models does not include all industries, a regression model was used to calculate GDP, to which value added for the identified key industries was used as factor. It is established that the proposed model is quite accurate and can be used to calculate the GDP of Ukraine on the basis of value added calculations in agriculture, extractive and processing industries. Given the prospects of practical use of the model for management decisions, the elasticity of the main driving factor (investments) of the development of individual industries was assessed for the main variables, which, in particular, showed that the exchange rate of hryvnia to the US dollar has a negative impact on investments, and the most pronounced – on investments in fixed assets of the processing industry. This questions the widespread idea that the devaluation of the hryvnia stimulates domestic production.

Influence of Saturated Organic Matter on the Accuracy of In-Situ Measurements Recorded with a Nuclear Moisture and Density Gauge

The impact of machines on forest soils is regularly assessed and quantified using absolute bulk density, which is most frequently obtained by soil cores. However, to allow for repeated measurements at the exact same locations, non-destructive devices are increasingly being used to determine soil bulk density and moisture content in field studies. An example of such a device is a nuclear moisture and density gauge (NMDG), originally designed as a control measurement for soil bulk density and moisture content in geotechnical applications. Unlike road construction or foundation projects that use mineral soil or gravel, forest soils have complex structures and the presence of organic matter, which can skew moisture and density readings from a NMDG. To gain further knowledge in this respect, we performed controlled tests in a sandbox to quantify the influence of varying amounts of saturated organic matter (3, 5, 10, and 15%) mixed with mineral soil in different layers (0–5, 0–10, 0–20 and 0–40 cm) on the accuracy of soil moisture content obtained by a NMDG and soil theta probe at varying depths. Main results illustrated that the presence of saturated organic matter per se was not problematic but moisture content overestimations and related underestimation of dry bulk density occurred when the tested measurement depth was below the created organic layer. Since forest soils often exhibit higher organic matter contents in the upper horizon, correction factors are suggested to minimize the moisture content variations between NMDG and reference method. With the use of correction factors, NMDG can present a non-destructive, fast, and accurate method of measuring soil moisture and bulk density in forestry applications.

Analysis of Applicability of Grid-based Spatial Analysis Data for Flood Risk Assessment

The risk assessment techniques currently used in Korea have proven to have limitations as they provide flood risk assessments only. Although these assessment techniques comprehensively evaluate various factors such as wind and flood damage and social disruption, the administrative task-handling capacity is limited at the local government level. In this study, using electronic maps (which include building and road name addresses) and number of buildings in 31 cities and counties in Gyeonggi-do, only the statistical values located within the impact range of flood damage were extracted and evaluated for flood risk. The differences in statistical values resulting from data types were supplemented by the use of correction factors in the grid data. As a result of calculating the detailed index of each local government in Gyeonggi Province using the corrected grid data, the index was calculated in this order: Hwaseong, Yongin and Pyeongtaek. However, when the flood risk map and the number of overlapping buildings were used, the index was calculated in this revised order: Goyang City, Gwangmyeong City, and Gimpo City. This provided results that are more accurate than that of the existing methodologies.

Herbarium-based measurements reliably estimate three functional traits.

The use of functional traits has surged in recent decades, providing new insights ranging from individual plant fitness to ecosystem processes. Global plant trait databases have advanced our understanding of plant functional diversity, but they remain incomplete because of geographic and taxonomic biases. Herbarium specimens may help fill these gaps by providing trait information across space and time. We tested whether herbarium specimen-derived measurements are reliable estimates of three important, commonly measured functional traits-specific leaf area (SLA), branch wood specific gravity, and leaf thickness. Leaves and branches were collected from species cultivated at Fairchild Tropical Botanic Garden and Florida International University in Miami, FL, USA. Fresh components of SLA (area), branch wood specific gravity (volume), and leaf thickness were measured following standard trait measurement protocols. We compared these trait values to corresponding measurements using plant tissues dried in a plant press following standard herbarium plant collecting protocols. Herbarium-derived trait measurements (dried tissues) were highly correlated with those measured using fresh tissues following standard protocols (SLA: R2 = 0.72-0.97, p < 0.01; wood specific gravity: R2 = 0.74-0.75, p < 0.01; leaf thickness: R2 = 0.96, p < 0.01). However, except for leaf thickness, linear model slope or intercept coefficients differed from 1, indicating herbarium-derived trait measurements may provide biased estimates of fresh traits without the use of correction factors. Herbarium-derived traits cannot always be used interchangeably with those measured from fresh tissues because of tissue shrinkage. However, herbarium-derived trait data still have the potential to drastically expand the temporal, geographic, and taxonomic scope of global trait databases.

Reducing Bias Due to Outcome Misclassification for Epidemiologic Studies Using EHR-derived Probabilistic Phenotypes.

Epidemiologic studies using electronic health record (EHR)-derived phenotypes as outcomes are subject to bias due to phenotyping error. In the case of dichotomous phenotypes, existing methods for misclassified outcomes can be used to reduce bias. In this article, we present a bias correction approach for EHR-derived probabilistic phenotypes: continuous predicted probabilities of the outcome of interest. This approach makes use of correction factors that can be computed by hand and do not require specialized software. We used simulation studies to investigate the performance of the proposed approach under a variety of scenarios for accuracy of the probabilistic phenotype, strength of the outcome/exposure association, and prevalence of the outcome of interest. Across all scenarios investigated, the proposed approach substantially reduced bias in association parameter estimates relative to a naive approach. We demonstrate the application of this approach to a study of pediatric type 2 diabetes using data from the PEDSnet network of children's hospitals. This straightforward correction factor can substantially reduce bias and improve the validity of EHR-based epidemiology.

Post Colectomy and Post Fixation Margin Measurement Correction Factor

This study evaluated the shrinkage of surgical margins in colorectal specimens prior to resection and at final examination and established a correction factor to ensure a sufficient resection margin. The proximal and distal surgical margins in normal anatomic positions were measured in patients with colorectal cancer prior to resection during surgery. Fresh specimens were sent to the pathology laboratory, and the distance of the tumor to the proximal and distal margins were measured before formalin fixation and after 24 h formalin fixation. The mean proximal surgical margins prior to resection, after resection, at 24 h after fixation, and after a histopathological examination were 19.8 (SD7.1) cm, 17 (SD7.5) cm, 14 (SD5.6) cm, and 13. 6 (SD5.3) cm, respectively. The values for the distal surgical margin were 12 (SD10.9) cm, 10.3 (SD9) cm, 7. 9 (SD7.7) cm and 7.7 (SD6.4) cm in respective order. The correction factor calculated for the proximal and distal resection margins prior to resection and after the final pathological examination were 1.45 and 1.55, respectively. It would be beneficial to establish and make use of correction factors when predicting shrinkages in surgical margins in curative colorectal cancer surgery.

Fat Mass in Young Malian Children with Moderate Acute Malnutrition: A Concern Regarding the Use of Correction Factors

Fat Mass in Young Malian Children with Moderate Acute Malnutrition: A Concern Regarding the Use of Correction Factors

Definition of Fuel and Lubricant Consumption Rates and Production of Tractor Units As Part of John Deere Tractors

Tractors are mainly applied in agriculture. The share of import in the structure of tractor machinery market is constantly growing. One of the information sources for the optimization of the machine and tractor fleet and the development of standards to satisfy the needs of typical farms in tractors and agricultural machines for crop production are the performance standards of machinery and fuel consumption. The recommended norms of fuel production and consumption imply the rational use of shift time, optimal composition of machine-tractor units and effective operation modes of tractors and self-travelling agricultural machines. In recent years, many tractors and agricultural machines of foreign companies, including John Deere, are working in the fields of Trans-Urals, Siberia and Russia as a whole. The standards of production and consumption of fuels and lubricants for these agro-climatic conditions are not available for all machine-tractor units. Therefore, it is becoming ever more relevant for agricultural producers to develop such. The studies to establish fuel consumption standards and performance rates of machine-tractor units as part of John Deere tractors were carried out in the fields of agricultural enterprises of the Tyumen Region. The paper presents the results of the study. For example, the productivity of a tractor for a field located at a distance of 5–6 km and an average length of furrow of 1300 m can be in the range of 5.8–6.0 ha/h. Taking into account natural and climatic conditions and different physical and mechanical composition of soil, as well as configuration of fields and length of furrows during processing, the data on the consumption of basic lubricants were obtained. Recommendations on the use of consumption rates for fuels and lubricants of modern tractors in various technological operations in agriculture will greatly facilitate planning and calculation of operating costs of machine-tractor units. The paper considers recommendations on the use of correction factors to the nominal range of fuel consumption depending on soil type for John Deere tractors of the 9th series on the example of disk tillage. Software for economic evaluation of agricultural machinery as part of agricultural technology was developed.

Evaluation of Diabetes Care parameters in capillary blood collected with a novel sampling device

ObjectivesThe aim of this study was to determine whether the Hem-Col method of obtaining and storing blood is an acceptable alternative to venepuncture for measuring Diabetes Care parameters. Design and methods: Hem-Col is a novel blood collection device that is designed to collect capillary blood drawn with a finger prick. Hem-Col is a microtube containing an anticoagulant and a preservation buffer to enhance analyte stability in whole blood. The Diabetes Care parameters cholesterol, creatinine, HbA1c, high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, and triglycerides were measured both in blood/plasma collected via Hem-Col and blood/plasma collected with venepuncture. The results were compared to assess the agreement between the two methods. Results: HbA1c shows agreement after storage for up to 120 hours at temperatures ranging from 4 to 37 °C. Cholesterol, HDL cholesterol, LDL cholesterol, triglycerides and creatinine can be measured after 120 hours of storage in Hem-Col buffer, if high temperatures are avoided, and with the use of correction factors or adaptations to reported reference intervals. Conclusion: Hem-Col is suitable for the measurement of HbA1c after storage for up to 120 hours at temperatures ranging from 4 to 37 °C. Cholesterol, creatinine, HDL cholesterol, LDL cholesterol and triglycerides can be measured after 120 hours of storage in Hem-Col buffer, if high temperatures are avoided. Further studies are required to determine whether Hem-Col can replace the venepuncture for the Diabetes Care parameters.

Determination of the humidity correction factor for use in dosimetry calculations

A variation on the air humidity can change the moist-air weight and density. The ion chambers that are commonly used in radiotherapy, connect with the surrounding air. In this paper, we examine the effect of relative humidity change in the ion chamber response. Since direct measurement of the humidity correction factor, kh, in the laboratory is difficult and time-consuming, in this work Monte Carlo simulation has been performed to obtain the kh factor. According to simulation results, at air temperature of 20°C and relative humidity between 20% and 80%, the kh factor is 0.9970. Finally, the necessary of using the kh factor in dosimetric calculations was investigated.

Comparison of different spectral resolution ICP-OES spectrometers for the determination of rare earth elements

This study investigates possible mutual spectral interferences of REEs for three commercially available spectrometers with different spectral resolutions. Comprehensive spectral interference data were obtained by using model solutions of REEs and spectral interference profiles of the most frequently used analytical lines are presented. The interference factors were calculated for line overlap correction and to confirm the effectiveness of the corrections, and model samples containing mixtures of rare earth elements were analyzed. This approach was useful only for spectrometers with low spectral resolution where the spectral interferences were found to be significant. As was expected, considerably better results were obtained by spectrometers with a high spectral resolution, as such corrections were unnecessary. The certified reference material REE-1 (the Strange Lake mine, Quebec, Canada) was used as a real sample representing REE-containing ore. Our results for both types of spectrometer confirm the assumption that high-spectral-resolution spectrometers provide better and more reliable results than low-spectral-resolution spectrometers with corrective factors. Nevertheless, the use of correction factors for the studied analytical lines does lead to improved results in many cases.

On the use of correction factors for the mathematical modeling of insulator based dielectrophoretic devices

Mathematical modeling is a fundamental component in the development of new microfluidics techniques and devices. Modeling allows for the rapid testing of new system configurations while saving resources. Microscale electrokinetic (EK) techniques have significantly benefited by the advances in modeling programs and software packages. However, EK phenomena are complex to model, as they dynamically affect system characteristics, including the physical properties of the particles and fluid within the system. Insulator-based dielectrophoresis (iDEP) is an EK technique that has received important attention during the last two decades. In particular, numerous research groups that study iDEP systems employ a combination of modeling and experimentation for developing new iDEP systems. An important fraction of these research groups has adopted the practice of employing "correction factors" to account for EK phenomena that cannot be accurately predicted in their models due to model complexity and limitations in computing resources. The present review article aims to provide the reader with an overview of the most common approaches in the use of correction factors for the modeling of iDEP systems.

STUDYING THE CHEMICAL COMPOSITION OF ESSENTIAL OIL RECEIVED FROM FRUITS OF PRANGOS ODON-TALGICA WILD-GROWING IN ASTRAKHAN REGION

The chemical composition of Prangos odontalgica (Pall.) Herrnst. et. Heyn essential oil, which grows wild in the Astrakhan region, has not been practically studied, unlike other species of the genus Prangos, growing in Iran, Turkey and Uzbekistan. To obtain the essential oil, all parts of the plant (roots, stems, flowers, leaves, fruits) are used, as well as various methods of isolation (hydrodistillation, supercritical fluid extraction, solid-phase microextraction, and others). Essential oil from the fruit of Prangos odontalgica we obtained by the method of hydrodistillation. The duration of the hydrodistillation process, established experimentally on the basis of a study of the dynamics of change in the yield of essential oil over time, was 3 hours. The yield of essential oil in mass% by volume in terms of absolutely dry raw materials according to the results of a threefold determination is 0.07 ± 0.01%. The method of gas-liquid chromatography carried out a quantitative analysis of the main components of the essential oil Prangos odontalgica. The quantitative content of the components of the essential oil was calculated by the areas of gas chromatographic peaks without the use of correction factors. Qualitative analysis was performed by comparing linear retention indices. In the Prangos odontalgica essential oil, 38 substances were identified (88.4%). It contains sesquiterpenes (31.48%), terpenoids (19.2%), hydrocarbons (15.39%), carboxylic acids and their esters (10.86%), alcohols, phenols (8.84%). Among sesquiterpenes, the predominant components are γ-elemen (9.84%), bisabolol (9.41%), and among terpenoids – trans-nerolidol (3.90%) and linalyl isobutyrate (3.41%).