Semiquantitative Determination Research Articles

Analysis of pentacyclic triterpenoids and phytosterols in cloudberry (Rubus chamaemorus L.) by LC-MS/MS.

Cloudberry (Rubus chamaemorus L.) is a plant rich in various biologically active compounds. In this work, the composition and concentrations of pentacyclic triterpenoids (PCTs) and phytosterols in various parts of cloudberries were studied using high-performance liquid chromatography-tandem mass spectrometry by multiple reaction monitoring mode (MRM, targeted analysis) and precursor ion scan mode (non-targeted analysis and semi-quantitative determination). Moderately polar fractions of cloudberry leaves, sepals and berries extracts are rich in β-sitosterol glycoside and various triterpenoid acids, among which tormentic acid (∼190-1800 μg/g dw part of cloudberries) and its hydroxyl derivatives (∼3.1-470 μg/g dw part of cloudberries) predominate. Non-polar fractions are characterised by the presence of amyrins (0.76-110 μg/g dw part of cloudberries), β-sitosterol (62-750 µg/g dw part of cloudberries) and β-sitosterol glycoside (∼92-360 μg/g dw sepals).

Determination of Cell-Free DNA (cfDNA) Methylation by Methylation-Sensitive High-Resolution Melting (MS-HRM) in Human Plasma for the Diagnosis of Gestational Diabetes Mellitus (GDM)

Considerable interest has focused on cell-free DNA (cfDNA) methylation for noninvasive prenatal diagnosis. We investigated maternal plasma DNA methylation using a simple protocol. Eighty plasma samples from pregnant women were separated for cfDNA methylation determination, including 13 from patients with gestational diabetes mellitus (GDM). Four CpG sites of the LHX3 gene were detected. The results show that methylation-sensitive high-resolution melting (MS-HRM) may be used for semi-quantitative determination of cfDNA methylation. There are extensive cfDNA methylation modifications at different gestational ages and different patterns were observed at different CpG sites. Hypermethylation was observed in the second trimester of pregnancy and GDM. Significant differences were observed in the two CpG sites in LHX3 between those with GDM and in the second trimester. It is suggested that cfDNA methylation and its level may be biomarkers for noninvasive prenatal diagnosis.

Analysis of 132 submandibular salivary glands using the Randox Evidence Investigator and Randox DOA ULTRA WB array.

Occasionally, obtaining an adequate or acceptable postmortem blood specimen for drug analysis is not possible due to factors such as decomposition, exsanguination, or embalming. Submandibular salivary gland tissue, one of three major types of salivary gland tissue in the oral cavity of humans, has been reported to be a viable alternative postmortem specimen for toxicological testing. In this study, we evaluated the performance of the Randox Evidence Investigator instrument and Randox DOA (Drugs of Abuse) Ultra Whole Blood Array for the semi-quantitative determination of 21 immunoassays in an alternative matrix, submandibular salivary gland tissue. We analyzed 132 submandibular salivary gland tissue specimens and compared the generated results to concomitantly collected postmortem whole blood specimen results. Oxycodone 2, meprobamate, barbiturate, benzodiazepine assay 1, zolpidem, and buprenorphine all showed perfect agreement (Cohen's kappa score = 1.00) between the submandibular salivary gland tissue results and the postmortem whole blood results; dextromethorphan, fentanyl, benzoylecgonine, methamphetamine, tricyclic antidepressants, oxycodone 1, and opiate showed an almost perfect agreement (Cohen's kappa score = 0.81-0.99); methadone, generic opioids, and amphetamine exhibited substantial agreement (Cohen's kappa score = 0.61-0.80). Tramadol demonstrated fair agreement (Cohen's kappa score = 0.41-0.60). The lowest measure of agreement was observed with cannabinoids, meeting criteria for slight agreement (Cohen's kappa score = 0.01-0.20). An application of the techniques described in this study could be implemented in postmortem toxicology laboratories as well as medical examiners offices to provide preliminary drugs of abuse test results that can be used to direct additional testing. This study highlights the successful integration of a novel specimen matrix and an "off-label" use of an established analytical technique.

Characteristics of environmental stress cracking of PE-HD induced by biodiesel and diesel fuels

In the context of the increasing effect of carbon dioxide emissions on the global climate biodiesel produced from renewable sources has emerged as a promising contender replacing fossil fuels, especially in long-range transport vehicles, using existing engines and infrastructure.High-density polyethylene is one of the prevailing materials for pipe and container applications for storage and transport of such fuels, both, from fossil and renewable resources. The contact with the respective fuels raises questions concerning material compatibility as biodiesel exhibits significant differences compared to conventional diesel fuel affecting its sorption and plasticization behavior in polyethylene. In this study, its behavior with respect to environmental stress cracking, considered one of the most frequent damage mechanisms leading to failure of polymer parts and packaging, was evaluated using the well-established Full Notch Creep Test. This approach allows for a detailed fracture surface analysis using imaging techniques, such as optical and laser scanning microscopy, as well as infrared spectroscopy. Comparing the environmental stress cracking behavior in standard surfactant solutions with that in biodiesel and diesel, respective crack propagation rates, showing different levels of acceleration, were determined and details of the underlying mechanisms could be revealed. Furthermore, the specific infrared absorption of the biodiesel's ester functionality allows its semi-quantitative determination on the fracture surface of the tested specimens after failure. Thus, a preferred uptake of sorptive fluids in the fracture zone due to local morphological changes of the polyethylene could be directly evidenced by infrared spectroscopy.

Utility of Point-of-Care Diagnosis of Chronic Heart Failure Using an Express Test for Semi-Quantitative Determination of NT-proBNP Levels.

To evaluate the accuracy of a rapid test for semi-quantitative determination of NT-proBNP levels in the diagnosis of CHF in comparison with quantitative assessment; to study the strength of the association of the results of this NT-proBNP test with indicators of the CHF severity. The concentration of NT-proBNP was determined in 44 patients at bedside both semi-quantitatively using an express test (BioTest, Novosibirsk) and quantitatively in a laboratory. In 11 patients, the severity of CHF was assessed with the CHF Clinical Status Scale (CSS). Echocardiography was performed in all patients. The sensitivity of the quantitative and semi-quantitative tests coincided and was 95%. The specificity of the quantitative test was 100% in our study, whereas the semi-quantitative test showed a specificity of 92%. The negative predictive value of either test was 96%. The diagnostic accuracy was 98% and 93%, respectively. In patients with significantly high NT-proBNP concentrations, the semi-quantitative test demonstrated a reduced ability to verify values above 1800 pg/ml; in patients with threshold concentrations, the semi-quantitative test showed an increased subthreshold sensitivity. Increases in the NT-proBNP concentration correlated with the severity of CHF according to the stage of the disease. Due to the sufficiently high sensitivity, specificity, ease of use, and speed of obtaining results, the rapid test for semi-quantitative measuring NT-proBNP is promising for outpatient screening bedside diagnosis of CHF and in the emergency room to confirm or exclude CHF. When determining the dynamics of NT-proBNP during the treatment of CHF, the use of the semi-quantitative rapid test with visual assessment of the results may produce an error compared to the quantitative assessment, which will probably not allow tracking the effect of therapy or predicting exacerbation of the disease.

Three in one: coordination-induced emission for inherent fluorescent Al-MOF synthesis combined with inner filter effect@aggregation-induced emission mechanisms for designing color tonality and ratiometric sensing platforms.

Three phenomena, namely coordination-induced emission (CIE), aggregation-induced emission (AIE), and inner filter effect (IFE), were incorporated into the design of a ratiometric and color tonality-based biosensor. Blue fluorescent Al-based metal-organic frameworks (FMIL-96) were prepared from non-emissive ligand and aluminum ions via CIE. Interestingly, the addition of tetracycline (TC) led to ratiometric detection and color tonality, as the blue emission at 380nm was quenched (when excited at 350nm) due to IFE, while the green-yellowish emission at 525nm was enhanced due to AIE. Based on that, an ultra-sensitive visual-based color tonality mode with smartphone assistance was developed for detection of TC. The sensor exhibited a linear relationship within a broad range of 2.0 to 85.0μMTC with a detection limit of68.0nM. TC in milk samples was quantified with high accuracy and precision. This integration of smartphone and visual fluorescence in solution isaccurate, reliable, cost-effective, and time-saving, providing an alternative strategy for the semi-quantitative determination of TC on-site.

Semi-quantitative analysis of formaldehyde in food using calibration chart based on number of colored wells of microwell plate titration

Microplate titration quantifies sodium hydroxide generated from formaldehyde reacting with excess sulfite in a 96-microwell plate. Phenolphthalein indicators change from red to colorless when all hydroxide ions react. Methodology optimized reagent concentrations, and reaction time and created a Calibration Chart for semi-quantitative determination. The chart shows formaldehyde concentration ranges corresponding to red well counts from 0 to 200 mM in 20 mM increments. Inter-operator repeatability demonstrates precision (3 replicates), correlating red wells with standard formaldehyde concentrations. This instrument-free technique uses readily available commercial plates, eliminating the need for specialized equipment and calibration. The methodology offers simplicity with its reliance on readily available commercial plates and minimal specialized equipment, hence it is cost-effective and easily transportable 96-microwell plates enhancing the methodology's portability, and efficient semi-quantitative analysis of formaldehyde. The analysis of twelve solutions from food samples agrees with the quantitative values using titration.

APPLICATION OF MODERN METHODS OF ANALYSIS FOR DETERMINATION OF POLLUTION AND IDENTIFICATION OF PLANT RAW MATERIALS

Quality control of herbal preparations is an important component to ensure the effectiveness and safety of their use. Phytochemical medicines are made from medicinal plant materials that may contain unwanted chemical compounds, so careful quality control must be performed to ensure their safety and efficacy. The success of quality control of herbal materials requires an integrated approach, i.e. a combination of various techniques and methods that allow analyzing the main classes of compounds. Various methods of analysis are used to overcome these difficulties. Today, the main chemical methods for determining the quality of medicinal products are chromatographic, in particular gas chromatography (GC), often combined with mass spectrometry (MS), liquid chromatography (HPLC), thin-layer chromatography (TLC), column chromatography (CC). Besides, HILIC is the optimal method for the analysis of polar and ionized compounds that are too strongly retained on polar stationary phases and/or poorly separated by standard chromatographic methods. TLC/HPTLC methods are traditionally used by the SPhU and the European Pharmacopoeia for identification of herbs and detection of impurities by visual assessment, as well as for semi-quantitative determination of compounds when comparing the intensity of the spot in the zone of the tested solution with spots in the zones of reference compounds. The mentioned methods have still remained the most acceptable for the identification of herbs, which is explained by the unique chromatographic profile of each plant or extract based on it. At the same time, the instrumental method of HPLC has advantages due to the possibility of quantitative determination of substances that fluoresce in UV or visible light. Nowadays, the direction of scientific research devoted to the optimization of the previously described analytical methods and the development of new ones for the identification of both herbs and herbal materials, as well as herbal remedies, becomes relevant. In addition, the development of methods for the quantitative determination of herbal compounds is a relevant scientific and practical direction.

A ratiometric fluorescence and colorimetry dual-signal sensing strategy based on o-phenylenediamine and AuNCs for determination of Cu2+ and glyphosate.

A ratiometric fluorescence sensing strategy has been developed for the determination of Cu2+ and glyphosate with high sensitivity and specificity based on OPD (o-phenylenediamine) and glutathione-stabilized gold nanoclusters (GSH-AuNCs). Water-soluble 1.75-nm size GSH-AuNCs with strong red fluorescence and maximum emission wavelength at 682nm were synthesized using GSH as the template. OPD was oxidized by Cu2+, which produced the bright yellow fluorescence oxidation product 2,3-diaminophenazine (DAP) with a maximum fluorescence emission peak at 570nm. When glyphosate existed in the system, the chelation between glyphosate and Cu2+ hindered the formation of DAP and reduced the fluorescence intensity of the system at the wavelength of 570nm. Meanwhile, the fluorescence intensity at the wavelength of 682nm remained basically stable. It exhibited a good linear relationship towards Cu2+ and glyphosate in water in the range 1.0-10 µM and 0.050-3.0µg/mL with a detection limit of 0.547 µM and 0.0028µg/mL, respectively. The method was also used for the semi-quantitative determination of Cu2+ and glyphosate in water by fluorescence color changes visually detected by the naked eyes in the range 1.0-10 µM and 0.30-3.0µg/mL, respectively. The sensing strategy showed higher sensitivity, more obvious color changes, and better disturbance performance, satisfying with the detection demands of Cu2+ and glyphosate in environmental water samples. The study provides a reliable detection strategy in the environment safety fields.

Effect of Al Substitution on Visible Short-Wave Infrared Reflectance Spectroscopy (VSWIR) of Goethite and Ferrihydrite

Goethite and ferrihydrite are the two major iron hydroxides, essential mineral constituents in the terrestrial surface system. Aluminum (Al) is the most common substituent in iron hydroxides, and it may significantly change the bulk and surficial physicochemical properties of iron hydroxides. Consequently, a practical and convenient approach is needed to efficiently identify the Al substitution degrees of iron hydroxides in natural occurrences. This study presents a comprehensive investigation of the VSWIR characteristics of laboratory-synthesized Al-substituted goethite and ferrihydrite, to establish diagnostic VSWIR parameters for the identification and quantification of Al substitution levels in iron hydroxides. The findings revealed that Al substitution can affect the band positions (P) of goethite and ferrihydrite at ~650 nm, ~900 nm, and ~1400 nm. The relationships between the Al substitution of ferrihydrite and VSWIR parameters can be expressed as P900 = −0.43 × Al(%) + 931 and P1400 = −0.07 × Al(%) + 1428, while that of goethite can be expressed as P650 = 0.42 × Al(%) + 657 and P900 = 2.29 × Al(%) + 936. The peak fitting results showed that the absorption intensity at 480–550 nm linearly decreases with increased Al substitution. The obtained VSWIR spectra of Al-substituted goethite and ferrihydrite provide a critical supplement to the spectral library for (Al) iron hydroxides, and these VSWIR parameters can be utilized for the semi-quantitative determination of Al substitution in natural iron hydroxides

Intact Transition Epitope Mapping-Force Interferences by Variable Extensions (ITEM-FIVE).

Investigations on binding strength differences of non-covalent protein complex components were performed by mass spectrometry. T4 fibritin foldon (T4Ff) is a well-studied miniprotein, which together with its biotinylated version served as model system to represent a compactly folded protein to which an Intrinsically Disordered Region (IDR) was attached. The apparent enthalpies of the gas phase dissociation reactions of the homo-trimeric foldon F-F-F and of the homo-trimeric triply biotinylated foldon bF-bF-bF have been determined to be rather similar (3.32 kJ/mol and 3.85 kJ/mol) but quite distinct from those of the singly and doubly biotinylated hetero-trimers F-F-bF and F-bF-bF (1.86 kJ/mol and 1.08 kJ/mol). Molecular dynamics simulations suggest that the ground states of the (biotinylated) T4Ff trimers are highly symmetric and well comparable to each other, indicating that the energy levels of all four (biotinylated) T4Ff trimer ground states are nearly indistinguishable. The experimentally determined differences and/or similarities in enthalpies of the complex dissociation reactions are explained by entropic spring effects, which are noticeable in the T4Ff hetero-trimers but not in the T4Ff homo-trimers. A lowering of the transition state energy levels of the T4Ff hetero-trimers seems likely because the biotin moieties, mimicking intrinsically disordered regions (IDRs), induced asymmetries in the transition states of the biotinylated T4Ff hetero-trimers. This transition state energy level lowering effect is absent in the T4Ff homo-trimer, as well as in the triply biotinylated T4Ff homo-trimer. In the latter, the IDR-associated entropic spring effects on complex stability cancel each other out. ITEM-FIVE enabled semi-quantitative determination of energy differences of complex dissociation reactions, whose differences were modulated by IDRs attached to compactly folded proteins.

Development of an analytical method for the determination of more than 300 pesticides and metabolites in the particulate and gaseous phase of ambient air

Pesticides can enter the atmosphere during spraying or after application, resulting in environmental or human exposure. The study describes the optimisation and validation of analytical methods for the determination of more than 300 pesticides in the particulate and gaseous phases of the air. Pesticides were sampled with high-volume air samplers on glass-fibre filters (GFFs) and glass columns filled with polyurethane foam (PUF) and XAD-2 resin. Comparing different extraction methods, a QuEChERS extraction with acetonitrile was selected for the GFFs. For the PUF/XAD-2 columns, a cold-column extraction with dichloromethane was used. Instrumental determination was performed using liquid chromatography/electrospray ionisation-time-of-flight mass spectrometry (LC/ESI-QTOF) and gas chromatography/electron impact ionisation-tandem mass spectrometry (GC/EI-MS/MS). Recovery experiments showed recovery rates between 70 and 120% for 263 compounds on the GFFs and 75 compounds on the PUF/XAD-2 columns. Semi-quantitative determination was performed for 39 compounds on the GFFs and 110 compounds on the PUF/XAD-2 columns. Finally, 27 compounds on the GFFs and 138 compounds on the PUF/XAD-2 columns could be determined only qualitatively. For the determination of the PUF/XAD-2 samples, signal suppression (LC) or signal enhancement (GC) due to matrix effects were determined. Method quantification limits of the optimised methods ranged from 30 to 240 pg/m3 for the target compounds on the GFFs, and from 8 to 60 pg/m3 on the PUF/XAD-2 columns. The applicability of the method was demonstrated by means of environmental air samples from an agricultural area in the Netherlands.

Effects of cell morphology, physiology, biochemistry and CHS genes on four flower colors of Impatiens uliginosa.

Flower color is one of the important ornamental traits in the plants, which plays an active role in attracting pollinators to pollinate plants and reproduce their offspring. The flower color of Impatiens uliginosa is rich, there are four main flower colors in nature: deep red, red, pink, and white. However, it remains unclear whether on four different flower colors mechanism of I. uliginosa. We investigate colorimetric measurement, observation of epidermal cells, cellular pH determination, extraction and determination of total anthocyanins and flavonoid, semi-quantitative determination of pigment components, and gene cloning and qRT-PCR of CHS genes to study four flower colors of I. uliginosa. The L* and b* values were the highest in white flower, while the a* values were the highest in pink flower. The same shape of epidermal cells was observed in different flower colors, which was all irregular flat polygons, and there were partial lignification. Their cellular pH values were weakly acidic, while the pH values of the deep red flower was the highest and the white flower was the lowest. The highest pigment content of the four flower colors was total anthocyanin content. And malvidin-3-galactosidechloride (C23H25ClO12), cyanidin-3-O-glucoside (C21H21O11) and delphinidin (C15H11O7) were the main pigment components affecting the color of four different flower colors. The anthocyanin synthesis gene IuCHS was expressed in four flowers, and all three copies of it had the highest expression level in pink flower and the lowest expression level in white flower. These results revealed the influence of main internal factors on four different flower colors of I. uliginosa, and provided a basis for further understanding of the intracellular and molecular regulatory mechanisms of flower color variation, and laid a foundation for the improvement of flower color breeding of Impatiens.

A solid-surface fluorescence study of Rhodamine B and fluorescein adsorbed onto a filter paper, and semi-quantitative determination using EEM data

A solid-surface fluorescence study of Rhodamine B and fluorescein adsorbed onto a filter paper, and semi-quantitative determination using EEM data

Valor diagnóstico de la microalbuminuria y la relación calcio / creatinina en la detección precoz de la preclampsia

Wc liave evaluated the biochemical and clinical parameters for early cletection of their alterations in pregnant woinen with late preeclampsia. Eighty nine patients between 24 and 32 gestation weeks were studied. Fifleen ofthem (18%) developed arterial hypertension (mean 141.5± 3111mHg). The perinatal results, gestational age at delivety, birth weight and Apgar score of the ncwborns were not signicantly different among the groups that were evualated. The microalbuminuria was analyzed through radioimmunoanalysis and reactive strips for the immunochemi cal semiquantitative determination. The calciura vas analyzedusing the cornpleximetric method and the urinaty creatinc using the colorirnetric method of Jaffe. No significative differences were found among the results ofeach evaluated method. The RIA showed greater sensibility, greater specificity and greater positive or negative predictive value with respect to other methods, but the differences were not wide enough to consider it the method of choice. In the group of patients (1115) who developed arterial hypertension. all the b iochemicalinethods showed a normal ity higher than 80%. We conclude that none of these methods used alone is useful for the early prediction of the appearance of prceclampsia.

Visual detection of H2O2 and glucose by HBcAb-HRP fluorescence-enhanced CdTe QDs/CDs ratiometric fluorescence sensing platform

This study presents the development of a sensitive and simple enhanced ratiometric fluorescence sensing platform in the consist of CdTe quantum dots (QDs), carbon dots (CDs), and hepatitis B core antibody labeled with horseradish peroxidase (HBcAb-HRP) for the visual analysis of H2O2 and glucose. The sulfur atoms in HBcAb-HRP have a strong affinity for Cd(II), which effectively enhances the fluorescence intensity of the CdTe QDs due to the generation of more radiative centers at the CdTe/Cd-SR complex. In the presence of H2O2, the Cd-S bonds are oxidized to form disulfide products and results in linear fluorescence quenching, while CDs maintain stable. Becasue glucose can be converted into H2O2 with the aid of glucose oxidase, this sensing platform can also be used for analyzing glucose. The detection limits for H2O2 and glucose are 2.9 μmol L−1 with RSD of 2.6% and 1.6 μmol L−1 with RSD of 2.4% respectively. In addition, under UV lamp irradiation, the orange-yellow CdTe QDs gradually quench with increasing H2O2 and glucose, while the blue CDs remain unchanged. A color change from orange-yellow to blue enables a visual semi-quantitative determination of H2O2 in commercial contact lens solution and glucose in human serum without any pretreatment. Thus, this CdTe QDs/CDs ratiometric sensing platform has significant potential for the rapid analysis of H2O2 and glucose in actual application.

Colorimetric surface lipid quantification in Drosophila.

Insects are covered with free neutral cuticular hydrocarbons (CHC) that may be linear, branched, and unsaturated and vary in their chain length. The CHC composition is species-specific and contributes to the adaptation of the animal to its ecological niche. Commonly, CHCs contribute substantially to the inward and outward barrier function of the cuticle and serve pheromonal communication. They are generally determined by gas-chromatography, a time-consuming method requiring detailed expertize, but it is not available in many laboratories. Here, we report on the establishment of a colorimetric method allowing semi-quantitative determination of unsaturated CHCs in Drosophila flies. This method is based on the in vitro reaction of vanillin with double bounds in lipid molecules in an acidic solution to generate a reddish color. We found a robust correlation between gas chromatographic and vanillin-colorimetric data on unsaturated CHCs amounts in single flies. As the role of unsaturated CHCs in the performance of insects in their environment is only partly understood, we think that this novel method would allow fast and broad analyses of this type of CHCs in insects both in the field and in laboratories and thereby contribute to a substantial improvement in the investigation of this matter.

Development and validation of spectrophotometric method and paper-based microfluidic devices for the quantitative determination of Amoxicillin in pure form and pharmaceutical formulations

There is a growing need for easy-to-use, low cost and portable quantitative assays to determine active pharmaceutical ingredients in the pharmaceutical industry. Here, we developed a batch spectrophotometric method and a method employing a paper-based microfluidic device for the estimation of Amoxicillin (AMX) in pure solution and pharmaceutical preparations. The detection depends on the coupling reaction of Amoxicillin with diazotized sulfadimidine (DSDM) in an alkaline medium. The yellow azo dye reaction product was measured at λmax 425 nm and linearity was observed from 2 to 30 mg L−1 with a detection limit of 0.32 mg L−1 and a quantification limit of 1.2 mg L−1 was found. The reaction was then transferred onto the paper-based microfluidic device and a plateau change in color intensity was found above 10 mg L−1. Thus, the paper-based microfluidic device can be applied for the semi-quantitative determination of Amoxicillin in pure solution and commercial pharmaceutical products for rapid screening.

Ancient Roman Coins from the Republican Age to the Imperial Age: A Multi-Analytical Approach

We report here the results of a multi-analytical approach to characterize twelve Roman coins dating from the third century B.C. to fifth century A.D. that were found in the surroundings of Rome and for which the year of minting is determined by numismatic analysis. The coins were studied using SEM-EDS, EMPA, XRD, and FTIR techniques, enabling semi-quantitative and quantitative determinations of the chemical and mineralogical composition of the alloys and corrosion products. SEM-EDS analyses highlighted the occurrence of corrosion products on the surfaces and wide chemical variations due to selective enrichment or depletions of the alloying metals. The EMP analyses showed that three of the twelve coins are made of copper (1), one is a copper–tin alloy (2), five are copper–tin–lead alloys with elements in different proportions (3), two are copper–lead alloys (4), and another one is a subaerata coin (5). In addition, the physical parameters of the coins, i.e., density, weight, and diameters, were measured to have an overall characterization.

ИССЛЕДОВАНИЕ МИКРОВКЛЮЧЕНИЙ МЕТАЛЛОВ И МИНЕРАЛОВ В ГОРНЫХ ПОРОДАХ: ПРОБЛЕМЫ ИНТЕРПРЕТАЦИИ РЕЗУЛЬТАТОВ И ИХ ПРИМЕНЕНИЕ ПРИ ИЗУЧЕНИИ МАГМАТОГЕННЫХ СИСТЕМ КАМЧАТКИ И СТАНОВОЙ СКЛАДЧАТОЙ ОБЛАСТИ

The article discusses the problems of interpreting the results of studies on microinclusions of metals and minerals by scanning electron microscopy with energy-dispersive X-ray microanalysis, which are related to the influence of the matrix material. The method was shown to work well when studying “relatively large” (5-10 μm) microinclusions for the purpose of their phase identification and semi-quantitative determination of composition normalized to 100%. The possibilities of “cleaning” the analysis results from “additives” introduced by matrix elements are discussed, as well as criteria for assessing the distance from the boundaries of a micro-object at which the influence of the matrix becomes minimal. The use of the results obtained using these approaches is illustrated by the examples of studying the petrology and metallogeny of igneous rocks of Kamchatka and the Stanovoy fold belt, during which new data were obtained on petrological processes in the mantle-crustal substrate beneath the active volcanic arc and on the evolution of the ore-magmatic system beneath the ancient active continental margin.