Instrumental Methods Of Analysis Research Articles

Development of a novel and fast XRF instrument for large area heavy metal detection integrated with UAV

The disadvantages of the current chemical and instrumental analysis methods for soil heavy metal pollution are that they have a high detection cost, long cycle times, and may cause secondary pollution. The aims of this study were to improve the rapid detection of soil heavy metal pollution over large areas. This study combined aircraft technology, embedded development, computer software, electronic information, and other technical methods to create a novel solution to the problem, i.e., an integrated unmanned aerial vehicle (UAV) based soil heavy metal pollution rapid detection system (UAV-SHMPRDS) was built. The key technologies required for a rapid detection system were developed, including the development of a hardware system based on a UAV and an X-ray fluorescence spectrum (XRF) analyzer, the design and implementation of a control system software system, and the implementation of a data inversion processing algorithm. Finally, a prototype UAV-SHMPRDS was constructed. Testing showed that the system improved regionalized soil heavy metal pollution detection efficiency. This study provides new solutions for the current problems encountered in the actual rapid detection of soil heavy metal pollution.

STUDY OF THE REASONS FOR CORROSION OF METALLIC OIL

Pipeline transport is considered to be the most efficient and economically feasible type, unlike rail, land or other types of transportation. Transported products are usually petroleum products with various physical and mechanical properties that can have various negative effects on the pipeline material, thereby causing corrosion, wear, leakage and emissions. The relevance of research in this direction is due to the fact that due to the relatively complex composition of Kazakhstan's oils during oil pumping, triboelectric effects at the phase interface cause the occurrence of electric charges, which lead to an increase in the efficiency of chemical reactions that cause corrosion of the pipeline material. Therefore, it is necessary to develop specific ways to protect oil pipelines from damage caused by metal corrosion. IR spectroscopic analysis of oil shows the presence of various types of hydrocarbons. Based on the oil dispersal of JSC Ozenmunaigas, the complexity in the molecular composition of oil causes electrical effects that lead to an increase in the corrosion rate. All this should be taken into account when developing corrosion protection. In the process of transportation in the volume of oil and petroleum products, due to the complex microstructure and certain heterogeneity of the macrostructure, electrostatic charges can be formed. Since electrification and heat generation occur during tribolytic effects, these processes require refinement of heat transfer processes at the micro-macro level. In this case, the potential difference between individual sections of the liquid volume can be quite large. Chemical and physico-chemical methods of instrumental analysis were used in the work. In this work, experimental values of the specific electrical conductivity of oil and petroleum products were obtained under laboratory conditions, which allow us to judge their dielectric nature. In this work, the triboelectric effect was studied at the site of the boundary of metals and organic liquids (oil, fuel oil, etc.) to determine their effect on the corrosion of pipeline metals. and the values of electrical conductivity of oils and petroleum products are established.

Functional and Structural Biological Methods for Palytoxin Detection

Palytoxin (PLTX) and its analogues are marine polyethers identified in Palythoa and Zoanthus corals, Ostreopsis dinoflagellates, and Trichodesmium cyanobacteria. Humans can be exposed to these toxins by different routes with a series of adverse effects but the most severe risk is associated with poisonings by the consumption of edible marine organisms accumulating these toxins, as occurs in (sub)-tropical areas. In temperate areas, adverse effects ascribed to PLTXs have been recorded after inhalation of marine aerosols and/or cutaneous contact with seawater during Ostreopsis blooms, as well as during cleaning procedures of Palythoa-containing home aquaria. Besides instrumental analytical methods, in the last years a series of alternative or complementary methods based on biological/biochemical tools have been developed for the rapid and specific PLTX detection required for risk assessment. These methods are usually sensitive, cost- and time-effective, and do not require highly specialized operators. Among them, structural immunoassays and functional cell-based assays are reviewed. The availability of specific anti-PLTX antibodies allowed the development of different sensitive structural assays, suitable for its detection also in complex matrices, such as mussels. In addition, knowing the mechanism of PLTX action, a series of functional identification methods has been developed. Despite some of them being limited by matrix effects and specificity issues, biological methods for PLTX detection represent a feasible tool, suitable for rapid screening.

Determination of polychlorinated naphthalenes in ambient air by isotope dilution gas chromatography-triple quadrupole mass spectrometry

环境空气中的多氯萘(PCNs)一般为痕量水平(pg/m3),要实现其准确定量必然对分析方法的提取、净化和仪器分析提出较高要求。研究通过考察提取溶剂种类、净化流程和色谱-质谱参数,建立了加速溶剂萃取(ASE)-多层硅胶复合中性氧化铝柱的净化方法,并利用同位素稀释气相色谱-三重四极杆质谱(GC-MS/MS)对环境空气中的多氯萘进行测定。同时,通过在采样、提取和进样分析前分别添加同位素内标,开展质量控制和保证。结果表明,在2~100 ng/mL范围内3~8氯萘的平均相对响应因子(RRF)的相对标准偏差(RSD)均小于16%。PCNs同类物的方法检出限为1~3 pg/m3(以样品体积为288 m3计算)。采用基质加标法评价了方法对环境空气样品中PCNs测定的精密度和准确度,低、中、高加标水平下3 ~8氯萘的平均加标回收率分别为89.0%~119.4%、98.6%~122.5%和93.7%~124.5%,测定结果的平均相对标准偏差分别为1.9%~7.0%、1.6%~6.6%和1.0%~4.8%。整个分析过程中,采样内标和提取内标的平均回收率分别为136.2%~146.0%和42.4%~78.1%, RSD分别为5.6%~7.5%和2.7%~17.5%,满足痕量分析的要求且平行性较好。方法的灵敏度和准确度高,精密度良好,适用于环境空气中3~8氯萘的准确定量测定,可在一定程度上缓解多氯萘监测对高分辨气相色谱-高分辨质谱的依赖,为实现多氯萘的国际履约提供方法支持。

High-resolution NMR and MALDI-MS molecular profiling of craft beers

Beer is a complex aqueous mixture of organic and inorganic compounds, such as carbohydrates obtained from barley or wheat malts, hops and yeast, ethanol, proteins, vitamins, and minerals. Phenols and their derivatives obtained by chemical interactions with biogenic amines, together superior alcohols and amino acids, are the other compounds present in minor proportions in beer, Phenolic components possess high antioxidant activities, and regulate the oxidative stability of beer, although bitterness of this beverage originates from hops. Since these antioxidants can produce beneficial effects on the human health after consumption, it is challenging to have in hand the molecular profiles of beers, in order to investigate their contents in bioactive compounds. Today, a significant number of small producers have strongly invested in craft beers, produced by using different hop blends, starting materials that are rich in phenolic antioxidants. The present work discloses an instrumental analytical method which enables the rapid obtainment of the molecular profiling of craft beers, with the assistance of selective extractions made by using multi-walled carbon nanotubes (MWCNTs). In this investigation, high-resolution 1H NMR, and LDMS and MS/MS analysis were applied for the “beeromic” analysis of a craft beer brewed in Calabria (the Southern part of Italy). The spectral data, confirmed that this kind of beer predominantly contains the hop bitter metabolites humolones and lupulones, also highlighting the presence of phenols and phenolamides which are known for their bioactivity against cancer. A profile of the principal volatile hop components was also obtained by GC-MS.

Физико-химический анализ почвенного покрова техногенно нарушенных территорий Кузбасса

As a result of coal mining, the natural landscapes of the Kemerovo region are involved in the process of global technogenic transformation. As a result of open-pit coal mining, catastrophic changes occur in ecosystems, which are accompanied by the destruction of the litho logical basis, degradation, transformation and displacement of huge tracts of soil cover. The aim is to study agro physical, agrochemical, sanitary and epidemiological indicators of soil samples of technogenically disturbed territories of Kuzbass. Objects of research. Samples of the surface layer of the external rock dump of LLC "Korchakolsky Section" the dump rock and the surface layer of the nearby territory, of the forest belt of the processing plant of LLC "JV "Barzassky Partnership" and the Taldinsky coal mine. The samples of undisturbed lands selected near the museum-reserve "Tomskaya Pisanitsa" were used as a reference. Methods. Agro physical (hygroscopic humidity, wilting humidity, soil density, soil porosity) and agrochemical (water and salt pH, total alkalinity, hydrolytic acidity, sum of exchange bases, dry residue, content of Cl–, SO₄2–, HCO3–, NO3–, Ca2+,Mg2+, Al) analysis of selected soil samples, including the content of pollutants of anthropogenic origin. The sanitary and epidemiological indicators of the samples were studied. Methods of chemical and instrumental analysis (electrochemical, chromatographic, molecular absorption spectroscopy) were used for research. Results. The analysis of the degree of technogenic disturbance of the studied landscapes is carried out. Samples of LLC JV "Barzassky Partnership" can be attributed to sandy loam soils of a slightly alkaline type. The nickel content exceeded the MPC by 1.26 times; the BGCP index by 25.25 times. Samples of the Korchakolsky section are attributed to sandy soils of a slightly alkaline type. The content of mobile phosphorus exceeded the MPC by 3.40 times, zinc by 1.1 times, nickel by 1.22 times, arsenic by 2.15 times; the BGCP index by 29.41 times. The samples of JSC Taldinsky Coal Mine are classified as sandy loam with a neutral reaction. The content of the mobile form of phosphorus exceeded the MPC by 5.22 times; nickel by 1.5 times; arsenic by 1.67 times. The samples of the reference soil are attributed to clay soils of a slightly alkaline type. The content of the mobile form of phosphorus exceeded the MPC by 2.27 times; nickel by 1.17 times, the BGCP index by 62.62 times. Conclusions. Based on the analysis of the composition of dump and quarry landscapes of technogenically disturbed territories of the Kemerovo region, detoxification of soils with the use of biological reclamation is recommended.

USAGE OF BI- AND POLYFUNCTIONAL COMPOUNDS AS AN ALTERNATIVE OF SYNTHETIC RESINS IN FI-BERBOARD TECHNOLOGY

Due to the high chemical activity of its filler, fiberboard is a unique material, it's formation can be ensured by chemical reactions of wood components. However, under hot pressing modes, typical for dry-process boards, chemical reactions do not have time to go through to the required extent, which requires the use of special modifiers that enhance the activity of the wood fiber. Bi- and polyfunctional compounds - sucrose, carbamide, and citric acid - were investigated as modifiers. The lowest efficiency was shown by sucrose, which is not able to ensure the compliance of the physical and mechanical parameters of the fiberboards with the requirements of standards; The use of urea and citric acid makes it possible to produce fiberboards that are not inferior in their properties to materials from urea-formaldehyde resin. Using the methods of chemical and instrumental analysis (IR spectroscopy, solid-state 13C NMR spectroscopy), it was found that during hot pressing, urea and citric acid react with components of the wood cell wall. Urea decomposes during pressing with the formation of ammonia and isocyanic acid, which, in turn, provides interfiber interaction. During hot pressing, citric acid reacts with hydroxyl groups of cell wall components by the esterification mechanism. Using the example of citric acid, it was found that plates that meet the requirements of the TSN-30 standart can be made only with a pressing time of 0.4 min / mm of the fiberboard thickness, which exceeds the technology requirements by more than two times. To ensure the competitiveness of the selected modifiers with respect to existing synthetic resins, it is necessary to find ways to reduce the pressing time.

Utilization of Suberinic Acids Containing Residue as an Adhesive for Particle Boards.

The birch (Betula spp.) outer bark is a valuable product rich in betulin. After removal of betulin extractives, suberin containing tissues are left. Suberin is a biopolyester built from α,ω-bifunctional fatty acids (suberinic acids), which after depolymerization together with lignocarbohydrate complex is a potential adhesive as a side-stream product (residue) from obtaining suberinic acids for polyol synthesis. In this work, we studied the utilization possibilities in particleboards of the said residue obtained by depolymerization in four different solvents (methanol, ethanol, isopropanol and 1-butanol). The adhesives were characterised by chemical (acid number, solubility in tetrahydrofuran, epoxy and ash content) and instrumental analytical methods (SEC-RID, DSC, TGA and FTIR). Based on the results of mechanical characteristics, ethanol was chosen as the most suitable depolymerization medium. The optimal hot-pressing parameters for particleboards were determined using the design of experiments approach: adhesive content 20 wt%; hot-pressing temperature 248 °C, and hot-pressing time 6.55 min.

Design of a tribotechnical diagnostics model for determining the technical condition of an internal combustion engine during its life cycle

The paper proposes a model of tribotechnical diagnostics, which allows us to determine the technical condition of an internal combustion engine within its life cycle and then take measures, including its decommissioning due to excessive wear of major components. The paper also focuses on tribodiagnostic methods that are suitable for assessing the technical condition of internal combustion engines used in various means of transport (automobiles, railway locomotives powered by internal combustion engines, aircraft powered by reciprocating internal combustion engines, special and garden equipment). An internal combustion engine from agricultural equipment was selected for the experiment and monitored throughout its life cycle. The paper describes in detail the appropriate methods used for the proposed tribotechnical diagnostics model, including the results from the measurements by these methods. The said methods were then evaluated and mutually compared. The following advanced instrumental analytical methods were used to evaluate the collected engine oil samples: atomic emission spectrometry (AES), ferrography, automatic laser counter and LNF particle classifier, FTIR infrared spectrometry. The result of the work (paper) is the design of a tribotechnical diagnostics model for determining the technical condition of an internal combustion engine during its life cycle and the determination of limit values for assessing the technical condition of a Honda GCV 165 internal combustion engine. The results are based on individual measurements

Association of Rural Hospital Admissions with Access, Treatment, and Mortality for Patients with Acute Myocardial Infarction in Shanxi, China.

China recently launched healthcare reforms to reduce disparities in healthcare resources between urban and rural areas. However, few studies have determined how admission to rural hospitals has affected patient care and outcomes. This study aims to determine whether admission to a rural hospital is associated with changes in treatment and outcomes. Using a province-wide, administrative database of 62,380 patients (51,355 urban patients vs. 11,025 rural patients) with acute myocardial infarction (AMI) in Shanxi from 2015 to 2017, we identified the differential distance from the patient’s residential address to the nearest hospital and the nearest percutaneous coronary intervention (PCI)-capable hospital as instrumental variables. We estimated the risk-adjusted differences in outcomes and treatments for patients admitted to rural hospitals versus urban hospitals using a two-stage least squares instrumental variable analysis method. Based on instrumental variable analysis, admission to a rural hospital was associated with a 5.3% (95% CI, 0.012 to 0.093; p = 0.011) increase in mortality. There was a 59.8% (95% CI, −0.733 to −0.463; p-values < 0.0001) decrease in receiving PCI, an 18.8% (95% CI, −0.231 to −0.146; p-values < 0.0001) decrease in receiving fibrinolysis, and a 71.8% (95% CI, 0.586 to 0.849; p-values < 0.0001) increase in receiving medication-only treatment for patients admitted to rural hospitals. Rural hospitals in China thus offer relatively poor care for myocardial infarction. Hospital facilities and reperfusion therapies must be improved.

Diagnosis of Thyroid Malignancy using Levels of Chemical Element Contents in Nodular Tissue

Introduction: Thyroid benign (TBN) and malignant (TMN) nodules are a common thyroid lesion. The differentiation of TMN often remains a clinical challenge and further improvements of TMN diagnostic accuracy are warranted. The aim of present study was to evaluate possibilities of using differences in chemical elements (ChEs) contents in nodular tissue for diagnosis of thyroid malignancy. Methods: Contents of ChEs such as aluminum (Al), boron (B), barium (Ba), calcium (Ca), chlorine (Cl), coper (Cu), iron (Fe), iodine (I), potassium (K), lithium (Li), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), sulfur (S), silicon (Si), strontium (Sr), vanadium (V), and zinc (Zn) were prospectively evaluated in “normal” thyroid (NT) of 105 individuals as well as in nodular tissue of thyroids with TBN (79 patients) and to TMN (41 patients). Measurements were performed using a combination of non-destructive and destructive methods: instrumental neutron activation analysis with high resolution spectrometry of short-lived radionuclides and inductively coupled plasma atomic emission spectrometry. Results: It was observed that in TMN tissue the mean mass fraction of I was lower while the mean mass fractions of K, Mg, and P were higher than in both NT and TBN groups of samples. It was demonstrated that I content is nodular tissue is the most informative parameter for the diagnosis of thyroid malignancy. It was found that “Sensitivity”, “Specificity” and “Accuracy” of TMN identification using the I level in the needle biopsy of affected thyroid tissue was significantly higher than that using US examination and cytological test of fine needle aspiration biopsy. Conclusions: It was concluded that determination of the I level in a needle biopsy of TNs using non-destructive instrumental analytical method is a fast, reliable, and very informative diagnostic tool that can be successfully used as an additional test of thyroid malignancy identification.

Revisiting low temperature oxidation chemistry of n-heptane

Benefitting from the rapid development of instrumental analysis methods, intermediate products that were difficult to probe in the past can now be measured and quantified in complex reaction systems. To understand low temperature reactions of interest for combustion applications, and reduce the deviations between model predictions and experimental measurements, constant advancement in understanding low temperature oxidation process is necessary. This work examines the oxidation of n-heptane in jet-stirred reactors at atmospheric pressure, with an initial n-heptane mole fraction of 0.005, equivalence ratio of 0.5, a residence time of 1s, and over a temperature range of 500-800 K. Reaction products were analyzed using synchrotron ultra-violet photoionization mass spectrometry, gas chromatography, and Fourier-transform infrared spectroscopy. Ignition delay times of n-heptane/O2/CO2 mixture were measured in a rapid compression machine at 20 and 40 bar over a 600-673 K temperature range. Based on the experimental results, a comprehensive kinetic model of n-heptane low temperature oxidation was developed by considering the sub-mechanisms of keto-hydroperoxide, cyclic ether, heptene isomers, and the third O2 addition reaction, and by updating the rate constants of keto-hydroperoxide decomposition and second oxygen addition reactions. The combination of reaction mechanism development and evaluation of the rate constants of key reactions enabled the model to effectively predict the species concentrations and ignition delay times of n-heptane low temperature oxidation, providing additional insight into alkane low temperature oxidation chemistry.

Determination of Fe and Tb concentrations in geological and environmental samples using the instrumental neutron activation analysis method combined with the γ − γ coincidence technique

The instrumental neutron activation analysis (INAA) method was combined with the γ − γ coincidence technique to measure Iron (Fe) and Terbium (Tb) concentrations in geological (Montana II Soil) and environmental (Coal Fly Ash) standard materials. The measured concentrations, which agree well with the corresponding certified values, are compared with those obtained from the traditional INAA method. It is demonstrated that employing the γ − γ coincidence technique slightly improves the accuracy of the analysis. Furthermore, the coincidence technique enhances the detection limits of Tb by ∼4.5 and ∼5.5 times in environmental and geological samples, respectively, but has almost no enhancement in those of Fe. The γ − γ coincidence technique therefore does not always promote the analysis quality of the INAA method, but it is effective for analyzing elements whose characteristic γ rays sustain a high Compton background and/or are overlapped with other γ rays.

Collaborative peer validation of a harmonized SPME-GC-MS method for analysis of selected volatile compounds in virgin olive oils

The requirement for developing an instrumental method for analysis of volatile compounds responsible for the aroma that supports the work of the sensory panel test of virgin olive oils is a matter of great importance. In this paper, five laboratories participated in a collaborative study within the EU H2020 OLEUM project to develop a peer interlaboratory study of a harmonized SPME-GC-MS method for determination of volatile compounds in virgin olive oil responsible for positive attributes (e.g. fruity) and the main sensory defects. Linearity (R 2 > 0.94) and repeatability (mean relative standard deviation, RSD% = 7.60%) were satisfactory. Reproducibility results were uneven depending on the compound. The lowest RSD% values were found for ( Z )-3-hexenyl acetate (19.19%), 1-hexanol (13.26%), and acetic acid (17.47%). The limits of quantification were <0.07 mg/kg for all compounds except for ( E )-2-decenal and pentanoic acid. The study of different quantification methods revealed that the correction of the calibration curves using the internal standard led to a slightly worse repeatability, but better accuracy and reproducibility. The results obtained by five laboratories are preparatory towards a trial proper validation study, already planned in OLEUM project, involving external labs participating on a voluntary basis. • A SPME-GC-MS based protocol with 3 possible quantification methods was developed. • A peer-interlab study was carried out (5 labs, 18 volatiles, 15 virgin olive oils). • Results were compared with a similar study carried with FID detector. • Linearity, recovery, precision and repeatability were satisfactory. • Three compounds showed reproducibility RSD >40%, partially due to high LOQs.

Diagnosis of Thyroid Malignancy Using Chemical Elements of Nodular Tissue Determined by Neutron Activation Analysis

Thyroid benign (TBN) and malignant (TMN) nodules are a common thyroid lesion. The differentiation of TMN often remains a clinical challenge and further improvements of TMN diagnostic accuracy are warranted. The aim of present study was to evaluate possibilities of using differences in chemical elements (ChEs) contents in nodular tissue for diagnosis of thyroid malignancy. Contents of ChEs such as calcium (Ca), chlorine (Cl), iodine (I), potassium (K), magnesium (Mg), manganese (Mn), and sodium (Na) were prospectively evaluated in “normal” thyroid (NT) of 105 individuals as well as in nodular tissue of thyroids with TBN (79 patients) and to TMN (41 patients). Measurements were performed using non-destructive instrumental neutron activation analysis. It was observed that in TMN tissue the mean mass fraction of I was lower while the mean mass fractions of K and Mg were higher than in NT and TBN tissue. It was demonstrated that I content is nodular tissue is the most informative parameter for the diagnosis of thyroid malignancy. It was found that “Sensitivity”, “Specificity” and “Accuracy” of TMN identification using the I level in the needle biopsy of affected thyroid tissue was significantly higher than that using US examination and cytological test of fine needle aspiration biopsy. It was concluded that determination of the I level in a needle biopsy of TNs using non-destructive instrumental analytical method is a fast, reliable, and very informative diagnostic tool that can be successfully used as an additional test of thyroid malignancy identification.

Special Issue on Application of Instrumental Methods for Food and Food By-Products Analysis

The application of various analytical procedures and methods determining the properties and safety of food and food constituents is a particularly important topic when dealing with food and food by-product analyses [...]

Content of Fifty Trace Elements in Thyroid Benign Nodules and Thyroid Tissue adjacent to Nodules investigated using Neutron Activation Analysis and Inductively Coupled Plasma Mass Spectrometry

Thyroid benign nodules (TBNs) are the most common diseases of this endocrine gland and are common worldwide. The etiology and pathogenesis of TBNs must be considered as multifactorial. The present study was performed to clarify the role of some trace elements (TEs) in the etiology of these thyroid disorders. Thyroid tissue levels of fifty TEs were prospectively evaluated in nodular tissue and tissue adjacent to nodules of 79 patients with TBNs. Measurements were performed using a combination of non-destructive instrumental neutron activation analysis and destructive method such as inductively coupled plasma mass spectrometry. Results of the study were additionally compared with previously obtained data for the same TEs in “normal” thyroid tissue. This study provides evidence on many TEs level alteration in nodular and adjacent to nodule tissue and shows the necessity to continue TEs research of TBNs.

Design, synthesis, anti-infective and anti-cancer potential of thiazole based Pyrazoles bearing benzothiazole moiety

A new series of (E)-6-methyl-N-((3-phenyl-1-(4-phenylthiazol-2-yl)-1H-pyrazol-4-yl)methylene)benzo[d]thiazol-2-amine derivatives was developed. Structural investigation of the synthesized derivatives was carried out by several instrumental method of analysis like IR, and 1H-NMR spectroscopy. The titled analogues were examined for in-vitro anticancer and antiinfective activities. The biological findings specified that analogues 5a, 5b, 5d, 5e, 5f and 5g showed most potent antibacterial activity (MIC 62.5-250μg/mL) and 5a, 5e, 5f and 5g displayed most potent antifungal action (MIC 62.5-500 μg/mL) than standard drugs. Compounds 5a and 5e were reported to be most active antimalarial analogue having IC50 value of 0.24-0.49μg/mL. Compounds 5a, 5e and 5f showed shortest mean paralysis time of (25.6±4.56 min, 26.4±4.97 min and 26.8±4.76 min) and mean death time (47.6±8.01min, 45.6±3.04min and 46.6±7.40min), respectively. Compound 5e showed moderate cytotoxicity with IC50 value of 65.4 against MCF-7. The results proved that 1,3-thiazolyl-pyrazole clubbed benzothiazole derivatives showed considerable antiinfective and cytotoxic activity. Keywords: Anti-infective activity, Cytotoxic activity, Spectroscopic methods, Thiazole, Pyrazole, Benzothiazole.

Diagnosis of thyroid malignancy using trace elements of nodular tissue determined by neutron activation analysis

Thyroid benign (TBN) and malignant (TMN) nodules are a common thyroid lesion. The differentiation of TMN often remains a clinical challenge and further improvements of TMN diagnostic accuracy are warranted. The aim of present study was to evaluate possibilities of using differences in trace elements (TEs) contents in nodular tissue for diagnosis of thyroid malignancy. Contents of TEs such as silver (Ag), cobalt (Co), chromium (Cr), iron (Fe), mercury (Hg), iodine (I), rubidium (Rb), antimony (Sb), scandium (Sc), selenium (Se), and zinc (Zn) were prospectively evaluated in “normal” thyroid (NT) of 105 individuals as well as in nodular tissue of thyroids with TBN (79 patients) and to TMN (41 patients). Measurements were performed using non-destructive instrumental neutron activation analysis. It was observed that in TMN tissue the mean mass fraction of I was lower while the mean mass fraction of Rb was higher than in NT and TBN tissue. It was demonstrated that I content in nodular tissue is the most informative parameter for the diagnosis of thyroid malignancy. It was found that “Sensitivity”, “Specificity” and “Accuracy” of TMN identification using the I level in the needle biopsy of affected thyroid tissue was significantly higher than that using US examination and cytological test of fine needle aspiration biopsy. It was concluded that determination of the I level in a needle biopsy of TNs using non-destructive instrumental analytical method is a fast, reliable, and very informative diagnostic tool that can be successfully used as an additional test of thyroid malignancy identification.

Loss of Sensory Cup Quality: Physiological and Chemical Changes during Green Coffee Storage.

Coffee is one of the most valued consumer products. Surprisingly, there is limited scientific knowledge about the biochemical processes during the storage of green coffee that affects its sensory quality. This review analyzes the impact of the different variables involved in the green coffee storage on quality from a chemical point of view. Further, it highlights the relationship between the physiological processes of the grain, its viability, and shelf-life. Notably, the storage conditions and postharvest treatment affect both the longevity and the sensory quality of the coffee, probably due to the biological behavior of green coffee. Various studies found modifications in their chemical profiles involving carbohydrates, lipids, proteins/amino acids, and phenolic compounds. To make future studies more comparable, we recommend standardized protocols for evaluating and linking the sensory coffee quality with instrumental analysis methods and pre-defined settings for experimental storage conditions.