Quantitative Compositional Analysis Research Articles

Fatty Acid Composition Analysis of Some Apiaceae Plants Using Gas Chromatography-Flame Ionization Detector (GC-FID)

Background/aim: The Apiaceae family, also referred to as the parsley or carrot family, comprises a diverse group of plants with significant ecological and economic importance. The fundamental building blocks of plant lipids, fatty acids are involved in a number of critical biological functions. Flame ionization detection in gas chromatography (GC-FID) is a potent analytical method widely used for the qualitative and quantitative analysis of fatty acid composition in plant samples. Materials and methods: In this study, we investigated the fatty acid profiles of several Apiaceae plants using GC-FID to elucidate their lipid composition and potential applications. Results: A wide spectrum of fatty acids was confirmed, ranging from C6:0 to C22:6. Astrodaucus orientalis leaf and fruit were found rich in palmitic acid (C16:0; 35.96% and 37.65%, respectively). Ferulago asparagifolia was determined as the richest sample in terms of poly-unsaturated fatty acids such as linoleic acid (C18:2 cis, 25.65%), alpha linoleic acid (C18:3n3, 7.42%) and eicosadienoic acid (C20:2, 32.66%). Ferulago syriaca ethanol and hexane extracts contained considerable amount of oleic acid (C 18:1 n9, 40. 37% and 49.19%, respectively). Conclusion: Our review of the literature revealed that no prior reports have been made about the fatty acid compositions of Astrodaucus orientalis, Ferulago asparagifolia and Ferulago syriaca. As a result, the information provided here may be the first to describe the fatty acid contents of these species. Exploring the lipid profiles of these plants can enhance their potential applications in the food, pharmaceutical, and cosmetic industries.

Quantitative analysis of spectral properties and composition of primitive achondrites (acapulcoites, lodranites and winonaites)

The establishment of robust meteorite-asteroid links has been a major focus of planetary exploration, and a major driver of asteroid sample return missions. Reflectance spectroscopy has been shown to be a powerful tool for this purpose. For the meteorites dominated by silicate minerals, quantitative analysis of spectral absorption features caused by the Fe2+-bearing minerals (mainly olivine and pyroxene) is a common method to determine mafic silicate mineralogy and end member abundances, and establish the relationship between them and possible parent bodies. In this study, the reflectance spectra of 22 primitive achondrites (acapulcoites, lodranites and winonaites) from NASA RELAB database were analyzed to determine their positions in the plot of the band area ratio (BAR) and 1 μm band center (Band I center). We found that Band I center and BAR of acapulcoites and lodranites are in roughly the same range. Acapulcoite-lodranite partially overlap with the field of H chondrites in the plot of the BAR and Band I center. This overlap means that spectral calibrations (also referred to as mineralogical formulas) based on the two types of meteorites needs to be applied with caution. The 2 μm band center of acapulcoite–lodranite is significantly lower than that of H chondrites, which is consistent with the conclusion of previous studies and provides a means to separate these two groups. In addition, the choice of spectral parameter analysis techniques may be a potential error source in similar studies. We provide generalized spectral fields of primitive achondrites in the plot of the BAR and Band I center derived from two widely used technologies.

Impact of barium oxide on the structure and surface properties of glass-crystalline glazes

The influence of barium oxide on glazes in the SiO2-Al2O3-CaO-MgO-K2O system was investigated. Samples were prepared with 0, 2.5, 5 and 7.5 wt% of barium oxide added to this system. The glazes were fired at 1240 °C and the structure and surface properties were determined. Qualitative and quantitative analyses of phase composition, surface properties, structural mid-infrared analysis, and microstructure were performed.Diopside was detected in all glazes as the MgO content was higher than 2.5 wt%. Hyalophane crystals were observed when the BaO content increased to 5 wt%. Mid-infrared studies showed that the appearance of crystalline phases ordered the structure of the glazes; on the other hand, the amorphous phase increased its disorder related to the higher amount of modifying barium cations. The addition of barium oxide did not significantly affect the color of the surface but caused an increase in roughness due to surface crystallization. The microhardness increased with an increased amount of barium in the amorphous phase.

Optimization of Parameters for Atom Probe Tomography Analysis of β-Tricalcium Phosphates.

The biocompatibility and resorption characteristics of β-tricalcium phosphate (β-TCP, Ca3(PO4)2) have made it a coveted alternative for bone grafts. However, the underlying mechanisms governing the biological interactions between β-tricalcium phosphate and osteoclasts remain elusive. It has been speculated that the composition at grain boundaries might vary and affect β-TCP resorption properties. Atom probe tomography (APT) offers a quantitative approach to assess the composition of the grain boundaries, and thus advance our comprehension of the biological responses within the microstructure and chemical composition at the nanoscale. The precise quantitative analysis of chemical composition remains a notable challenge in APT, primarily due to the influence of measurement conditions on compositional accuracy. In this study, we investigated the impact of laser pulse energy on the composition of β-TCP using APT, aiming for the most precise Ca:P ratio and consistent results across multiple analyses performed with different sets of analysis conditions and on two different instruments.

KINEMATIC PARAMETERS, PHYSICAL CHARACTERISTICS, AND CHEMICAL COMPOSITION OF SELECTED METEOR BODIES

Background. Meteoroids can reach the Earth and penetrate its atmosphere creating meteor phenomena. Kinematic parameters, physical characteristics, and chemical compositions of the observed meteor bodies provide information about the properties of their parent bodies — comets and asteroids. On the other hand, these parameters can reflect the physical conditions of meteor- oids staying in different parts of the Solar System and beyond. Methods. The meteor data analyzed in this work were obtained from observations using the automatical video and spectral meteor patrol (AVSMP) of the Institute of Astronomy of V. N. Karazin Kharkiv National University. The methods of meteor astronomy and spectroscopy make it possible to determine the kinematic parameters, physical properties, and chemical com- position of the meteoroids that we studied. Results. The paper presents the research results of meteors brighter than 0m that were recorded by the multi-stations method. These meteors also have spectral observations. For the selected 12 meteors, we obtained the coordinates of meteor radiants on the celestial sphere, the parameters of the atmospheric trajectories of meteor bodies, and the heliocentric orbital parameters of the observed meteoroids for the epoch (J2000). The extra-atmospheric masses of meteoroids were determined from photometric data. The identified emission lines detected in meteor spectra were analyzed. The software developed by the authors of this paper for me- teor spectra processing was used. Qualitative and quantitative analyses of the chemical composition of meteor bodies were carried out. During the quantitative analysis, the values of the relative intensities of the Fe I-15, Mg I-2, and Na I-1 lines were determined. Conclusions. Kinematic parameters and elements of heliocentric orbits presented in this work indicate that the observed me- teor bodies belong to meteor showers and their comets, such as Perseids, Leonids, and Southern Taurids. Some meteor bodies are sporadic. The calculated masses of meteoroids have some scatter of values, but they are generally consistent with observa- tions of other authors in the range of absolute values of the meteor brightness -2m…+1.5m. It was found that some of the studied meteor bodies are Fe-poor or Na-poor in their chemical composition.

Quantitative composition analysis of natural gas by high-pressure proton low-field NMR spectroscopy: Development of an improved experimental methodology

Natural gas (NG) has been proposed as a bridging fuel between fossil and renewable energy sources, playing a significant role in the decarbonization of the energy sector. Its commercial value and the integrity of the NG infrastructure depend on the NG physical properties, which are strongly related to its composition. Thus, the development of low-cost and reliable analytical methods for composition analysis of NG can enable a more efficient operation. Recently, we showed that high-pressure (HP) benchtop 1H NMR spectroscopy combined with indirect hard modelling (IHM) is an efficient and low-cost method for composition quantification of NG. The current work extends this methodology by introducing and testing novel experimental strategies for increasing the reliability and accuracy of the method. This new approach includes the use of a recently published high-pressure tube design and single-scan acquisition combined with novel quality control parameters to obtain highly reproducible peak shape 1H NMR spectra over long periods. The proposed methodology tested on binary, ternary, and more complex mixtures at 200 bar and 160 bar gives compositions in excellent agreement with the vendor certificates.

Spectroscopic assessment and quantitative analysis of the trace element composition of vegetable additives to meat products

In this scientific work, using the method of laser-induced breakdown spectroscopy (LIBS), the spectra of beef samples and impurities in meat products, namely, banana, pineapple, kiwi, bergamot, poria coconut, Chinese angelica, chicken blood vine, were measured by using developed experimental devices. The purpose of the research was to evaluate the qualitative characteristics of additives to meat semi-finished products for the potential formation of the desired properties of the products due to the analysis of the received spectrograms of trace elements of the samples when applying the LIBS method, quantitative analysis for processing the received information. The determined values of the electron temperature of the plasma, the electron density of the used raw material samples, and the assessment of the local heat balance were used as evaluation criteria. When processing the obtained data, the characteristics of the laser-induced plasma surface of the presented samples were analyzed; the electron temperature and electron density were determined, and a quantitative analysis of trace elements was carried out. LIBS technology allows rapid real-time monitoring and qualitative analysis of trace elements online and over long distances. During the research, it turned out that quantitative analysis requires further study and optimisation of experimental conditions, such as pre-treatment of samples. These conditions optimise defocusing, double laser pulse, and sample temperature, which increases the signal/noise ratio of all spectral lines. The combination of fluorescence spectroscopy and Raman technology enables higher detection sensitivity and better molecule control, creating a quantitative analysis method model that can reduce matrix effects and overcome the self-absorption effect. Among the difficulties of using LIBS technology, several elements can be noted online simultaneously, compared to Raman. The combination of spectroscopy and fluorescence spectroscopy can obtain more comprehensive information about the composition of materials, which can become a potential platform for monitoring trace elements in food products.

Research on the pharmacognostic characteristics, physicochemical properties and in vitro antioxidant potency of Rosa laxa Retz. flos.

Rosa laxa Retz. is an unexplored Rosaceae plant in Xinjiang, China, and its flower is traditionally used in Kazak to treat the common cold, fever, and epileptic seizures and lessen the effects of aging. In the present study, the pharmacognostic profiles, physicochemical properties, phytochemical characteristics, and in vitro antioxidant potency of Rosa laxa Retz. flos (RLF) were presented. In the pharmacognostic evaluation of RLF, organoleptic characteristics, internal structures, and powder information were observed, and physicochemical parameters, including moisture content, ash, pH value, swelling degree, and extractives were examined. The quantitative analysis of the chemical composition of four different polar extracts of RLF showed that the aqueous part had the highest total triterpene acid, flavonoid, and polyphenol content (4.50 ± 0.04 mg/g, 50.56 ± 0.03 mg/g, and 60.20 ± 0.09 mg/g, respectively). A high-performance liquid chromatography (HPLC)-diode array detector (DAD) method was established and the contents of gallic acid, ellagic acid, astragalin, and tiliroside in RLF were determined simultaneously. In the set concentration range, the linear relationship among the four components was good (r > 0.999), the average recoveries were 97.36%-100.54%. The contents of gallic acid, ellagic acid, astragalin, and tiliroside in RLF samples were (9.46 ± 2.31) mg/g, (10.60 ±0.75) mg/g, (1.13 ± 2.50) mg/g, and (1.11 ± 2.65) mg/g, respectively. The types of its secondary metabolites were determined by fluorescence, color reaction by chemical solvent method, and ultraviolet-visible (UV-Vis) spectroscopy. The functional groups of its secondary metabolites were determined by Fourier transform infrared (FTIR) spectroscopy. Results showed that RLF contains a variety of secondary metabolic products, including flavonoids, phenolic acid, glycoside, and organic acid. TLC identification showed it contains ursolic acid, β-sitosterol, tiliroside, astragalin, isoquercitrin, kaempferol-3-O-rutinoside, gallic acid, and ellagic acid. The in vitro antioxidant activity of different polar parts of RLF was investigated by DPPH, ABTS, and reduction performance experiments. The aqueous extract had the strongest antioxidant capacity, consistent with the high content of triterpene acids, flavonoids, and polyphenolic compounds. These findings will provide critical information for the study of quality standards and medicinal value of RLF and its extracts, justify its usage in traditional medicinal systems, and encourage the use of this plant in disease prevention and treatment. Its phytochemical composition and pharmacological studies need to be explored in future. RESEARCH HIGHLIGHTS: Optical microscope and scanning electron microscope (SEM) were used to observe the morphology, and microstructure of Rosa laxa Retz. flos (RLF). The physicochemical properties, fluorescence and phytochemical composition of four different polar extracts of RLF were analyzed by UV-Vis and FTIR. Determination of total triterpenic acid, total flavonoids, and total polyphenols in four different polar extracts of RLF by UV spectrophotometry. A high-performance liquid chromatography (HPLC)-diode array detector (DAD) method was established and the contents of gallic acid, ellagic acid, astragalin, and tiliroside in RLF were determined simultaneously. TLC confirmed that RLF contains ursolic acid, β-sitosterol, tiliroside, astragalin, isoquercitrin, kaempferol 3-rutinoside, gallic acid, and ellagic acid. The in vitro antioxidant activity of RLF was studied by DPPH, ABTS, and reducing ability experiments.

Rapid quantitative analysis of coal composition using laser-induced breakdown spectroscopy coupled with random forest algorithm.

Coal is the primary energy source in China, widely used in energy production, industrial processes, and chemical engineering. Due to the complexity and diversity of coal quality, there is an urgent need for new technologies to achieve rapid and accurate detection and analysis of coal, aiming to improve coal resource utilization and reduce pollutant emissions. This study proposes a rapid quantitative analysis of coal using laser-induced breakdown spectroscopy combined with the random forest algorithm. Firstly, a Q-switched Nd: YAG laser at 1064nm was employed to ablate coal samples, generating plasma, and spectral data were collected using a spectrometer. Secondly, the study explores the impact of different parameters in the preprocessing method (wavelet transform) on the predictive performance of the random forest model. It identifies elements related to coal ash content and calorific value along with their spectral information. Subsequently, to further validate the predictive performance of the model, a comparison is made with models established using support vector machine, artificial neural network, and partial least squares. Finally, under optimal parameters for spectral information preprocessing (wavelet transform with Db4 as the base function and 3 decomposition levels), a model combining wavelet transform with Random Forest is established to predict and analyze the ash content and calorific value of coal. The results demonstrate that the Wavelet Transform-Random Forest model exhibits excellent predictive performance (coal ash content: R2 = 0.9470, RMSECV = 4.8594, RMSEP = 4.8450; coal calorific value: R2 = 0.9485, RMSECV = 1.5996, RMSEP = 1.5949). Therefore, laser-induced breakdown spectroscopy combined with the random forest algorithm is an effective method for rapid and accurate detection and analysis of coal. The predicted coal composition values show high accuracy, providing insights and methods for coal composition monitoring and analysis.

LIBS combined with SG-SPXY spectral data pre-processing for cement raw meal composition analysis.

Rapid testing of cement raw meal plays a crucial role in the cement production process, so there is an urgent need for a fast and accurate testing method. In this paper, a method based on the Savitzky-Golay (SG) smoothing and sample set partitioning based on joint x-y distance (SPXY) spectral data pre-processing is proposed to improve the accuracy of the laser-induced breakdown spectroscopy (LIBS) technique for quantitative analysis of cement raw meal components. Firstly, the spectral data is denoised by SG smoothing, which effectively reduces the noise and baseline variations in the spectra. Then, the denoised data is divided into sample sets by combining the SPXY sample division method, which improves the efficiency of data analysis. Finally, the delineated data set is modeled for quantitative analysis by a back-propagation (BP) neural network. Compared to the modeling effect of the four oxide contents of CaO, S i O 2, A l 2 O 3, and F e 2 O 3 in the Hold-Out method, the correlation coefficient (R) was improved by 26%, 10%, 17%, and 4%, respectively. The root mean square error (RMSE) was reduced by 47%, 33%, 43%, and 21%, respectively. The mean absolute percentage error (MAPE) was reduced by 63%, 60%, 36%, and 51%, respectively. The results show that there is a significant improvement in the model effect, which can effectively improve the accuracy of quantitative analysis of cement raw meal composition by LIBS. This is of great significance for the real-time detection of cement raw meal composition analysis.

In situ and ex situ quantification of nanoparticle fluxes in magnetron sputter inert gas condensation: A Cu nanoparticle case study

Magnetron sputter inert gas condensation was coupled with quadrupole mass spectrometry for the in situ characterization of a nanoparticle beam. The proposed method allows us to determine the size distribution and the mass flux of the nanoparticles. The measured quadrupole mass spectrometer grid current is converted into a nanoparticle flux and subsequently into a mass flux. Cu nanoparticles were deposited onto Si substrates using different filtering modes of the quadrupole mass spectrometer. Characterization was carried out using a combination of x-ray photoelectron spectroscopy and scanning electron microscopy. Quantitative analysis of the elemental composition of the Si surface revealed a Gaussian distribution of the deposited nanoparticles over the diameter of the rotating substrate holder with a good quantitative agreement with the predictions made from the in situ quantification method.

Application of a whey protein ingredient for simultaneous co-enrichment of infant formula with α-lactalbumin and milk fat globule membrane

α-Lactalbumin (α-lac) and milk fat globule membrane (MFGM) are bioactive components of human milk beneficial for infant health and development. The strategic design of high-quality dairy ingredients, to include bioactive components such as α-lac and MFGM can contribute to the continued scientific advancement of infant formula (IF). It was demonstrated in this study that a unique whey protein ingredient could be used to achieve co-enrichment of IF with α-lac and MFGM. Model IF containing alternative whey ingredients specifically enriched in either α-lac or MFGM were also designed for comparison. A further finding was that the magnitude of IF MFGM enrichment could not be confirmed using microscopy alone and so, quantitative compositional analysis was required. This research demonstrated that the bioactive profile of an IF could be enhanced by selecting a unique whey protein ingredient co-enriched in α-lac and MFGM during formulation.

Analysis of Cation Composition in Dolomites on the Intact Particles Sampled from Asteroid Ryugu.

Characterization of the elemental distribution of samples with rough surfaces has been strongly desired for the analysis of various natural and artificial materials. Particularly for pristine and rare analytes with micrometer sizes embedded on specimen surfaces, non-invasive and matrix effect-free analysis is required without surface polishing treatment. To satisfy these requirements, we proposed a new method employing the sequential combination of two imaging modalities, i.e., microenergy-dispersive X-ray fluorescence (micro-XRF) and Raman micro-spectroscopy. The applicability of the developed method is tested by the quantitative analysis of cation composition in micrometer-sized carbonate grains on the surfaces of intact particles sampled directly from the asteroid Ryugu. The first step of micro-XRF imaging enabled a quick search for the sparsely scattered and micrometer-sized carbonates by the codistributions of Ca2+ and Mn2+ on the Mg2+- and Fe2+-rich phyllosilicate matrix. The following step of Raman micro-spectroscopy probed the carbonate grains and analyzed their cation composition (Ca2+, Mg2+, and Fe2+ + Mn2+) in a matrix effect-free manner via the systematic Raman shifts of the lattice modes. The carbonates were basically assigned to ferroan dolomite bearing a considerable amount of Fe2+ + Mn2+ at around 10 atom %. These results are in good accordance with the assignments reported by scanning electron microscopy-energy-dispersive X-ray spectroscopy, where the thin-sectioned and surface-polished Ryugu particles were applicable. The proposed method requires neither sectioning nor surface polishing; hence, it can be applied to the remote sensing apparatus on spacecrafts and planetary rovers. Furthermore, the non-invasive and matrix effect-free characterization will provide a reliable analytical tool for quantitative analysis of the elemental distribution on the samples with surface roughness and chemical heterogeneity at a micrometer scale, such as art paintings, traditional crafts with decorated shapes, as well as sands and rocks with complex morphologies in nature.

Quantitative and Qualitative Phytochemical Analysis of Manilkara zapota (Sapodilla) Extract and Its Antibacterial Activity on Some Gram-Positive and Gram-Negative Bacteria.

A molecule's antibacterial and antiviral action is exclusively linked to substances that selectively eradicate bacteria and viruses or inhibit their growth without significantly damaging adjacent tissues. The purpose of this research is to evaluate quantitative and qualitative phytochemical analysis and the antibacterial effects of Manilkara zapota fruit extract on some Gram-positive (Staphylococcus aureus, Enterococcus faecalis, Micrococcus luteus, Bacillus cereus, and Listeria monocytogenes) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae) bacteria in laboratory conditions. Qualitative chemical screening was used to identify different classes of active chemical compounds, and quantitative analysis of the chemical composition of the plant was used to measure the contents of flavonoid, total phenol, anthocyanin, and antioxidant activity. Antibacterial effects of Manilkara zapota ethanol extract were determined by disk diffusion methods, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). Qualitative chemical screening revealed the presence of flavonoids, tannins, quinones, terpenoids, and glycosides while the presence of saponins was not observed. The bacterial inhibition zones against Listeria monocytogenes, Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Klebsiella pneumoniae, and Bacillus cereus are 15.44 ± 0.33, 12.23 ± 0.11, 8.85 ± 0.2, 14.22 ± 0.33, 15 ± 0.44, 9.33 ± 0.13, 10.33 ± 0.36 and 14.55 ± 0.45 mm, respectively. MIC and MBC of the extract in Gram-positive bacteria were 25 and 50, and in Gram-negative bacteria were 50 and 100 mg/ml, respectively. The findings imply that Manilkara zapota extract includes a good amount of plant compounds and can be a significant source for a variety of uses, including antibacterial.

Xenotime-(Y) from granitic pegmatites of the Monatsitovaya mine, Aduisky massif, Middle Urals (chemical composition and age)

The relevance of the work is due to the need to improve the chemical dating method as applied to high-uranium and high-thorium accessory minerals, which are difficult to study using isotopic research methods. The purpose of the work is to study the chemical composition of accessory xenotime from granite pegmatites of the Monatsitovaya mine (western part of the Aduisky massif) and determine its age. Research methodology. A quantitative analysis of the chemical composition of monazite was performed on a CAMECA SX 100 electron probe microanalyzer (IGG Ural Branch RAS, Ekaterinburg). Measurement conditions: accelerating voltage 15 kV, current 250 nA, electron beam diameter 2 μm. The pressure in the sample chamber is 2 × 10–4 Pa. The spectra were obtained on inclined wave spectrometers, the intensity measurements were carried out along the analytical lines: Y Lα, Si Kα, (TAP crystal analyzer), U Mβ, Pb Mα, Ca Kα, Th Mα, P Kα (PET), Yb Lα, Dy Lα, Er Lα, Gd Lα, Lu Lα, Sm Lβ (LiF). The overlap of peaks of spectral lines was taken into account, which is extremely important in the quantitative determination of lead content (the Y Lγ2,3 и Th Mζ1,2 lines are superimposed on the analytical Pb Mα line). The pulse accumulation time at the peaks of analytical lines was twice as long as for the background and was 60 s for Th, 40 s for U and Pb, and 10 s for other elements. When conducting research, linear experimental design was used to vary the time of measuring the intensities of the Mβ line of uranium, Mα lines of thorium and lead. The calculated detection limits are 345 ppm for U, 283 ppm for Th, 65 ppm for Pb, 205 ppm for Y. Results. It has been established that xenotime belongs to the yttrium variety and is characterized by an increased content of uranium (UO2 up to 8.8 wt. %) and thorium (ThO2 up to 4.5 wt. %). According to the results of chemical dating (based on 32 analyses), xenotime-(Y) shows a weighted average age of 276 ± 7 Ma (MSWD = 0.54). When constructing the dependence (ThO2 +UO2 eq) – PbO, the points fall on one isochron. Calculating the age using the isochron slope angle gave a dating of 276 ± 12 million years (MSWD = 0.94). Conclusions. The obtained age values for the xenotime are in good agreement with the dating of the pegmatoid granites of the Krutikhinsky massif, which is located on the western contact of the Aduisky granite massif and relatively close to the Monatsitovaya mine. It is quite possible that some pegmatites in the western part of the Aduisky massif were formed as a result of the formation of the Krutikhinsky massif.

Effects of Light and Feeding on Expressions of Clock Genes and Metabolic Genes in the Ridgetail Shrimp, Exopalaemon carinicauda

The changes of the circadian clock genes expression, growth, and muscle composition in Exopalaemon carinicauda under different photoperiods and feeding time were investigated by real-time fluorescence quantitative PCR and muscle biochemical composition analysis, respectively. Results showed that four clock genes of Clock, Cry1, Tim, and Per2 showed significant circadian rhythms in both eyestalk and hepatopancreas. Their expression rhythms were highly correlated with the photoperiod in the eyestalk, but in the hepatopancreas, it was significantly correlated with the feeding time. Moreover, the expressions of several metabolic genes were also variable; adipose triglyceride lipase (ATGL) and amyloglucosidase (AGL) changed significantly with the shift of feeding time, whereas methionine synthase (MS) and succinate dehydrogenase (SDH) changed significantly with the photoperiod. This reflected the close relationship between the metabolic and circadian clock in E. carinicauda; Alterations in photoperiod or feeding time lead to changes in the biological clock systems, which affects the daily expression of metabolic genes at the downstream metabolic pathway and closely correlates their expression rhythms with epi-environmental factors such as feeding. It can be seen from the results that the feeding was also a significant factor that affected the crude protein and crude fat contents in muscle tissue of E. carinicauda; their highest values (18.69% ± 0.13%, 1.81% ± 0.02%) were also occurred in the treatment with feeding at 19:00. Differences in muscle composition through a similar mechanism of action, i.e., the biological clock system are affected by the feeding and then regulated changes in downstream metabolic processes. As a result, the optimized conditions for the cultivation of E. carinicauda were a short light-phase photoperiod (8L : 16D) with feeding after sunset (19:00).

Analysis of the Chemical Composition and Structure of Micrometer-Thick Complex Oxide Films: A Case Study of a MgAl2O4 Film on SiO2 Using Electron Probe Microanalysis and Confocal Raman Spectroscopy

Methodological approaches to both qualitative structural analysis and quantitative compositional analysis of transparent complex oxide films on dielectric substrates, performed using a Horiba LabRAM HR800 confocal Raman spectrometer and a Cameca SX100 electron probe microanalyzer, are described. The studies were carried out using magnesium–aluminum spinel films of a thickness of 1–3 µm on a quartz glass substrate, obtained by magnetron sputtering. The characterization of the film structure consisted of recording 3D arrays of its Raman spectra based on z depth profiling. The film has a disordered spinel structure with a partially reversed distribution of Mg and Al cations over octa- and tetra-positions. Operation parameters are identified to evaluate the concentration of structure-forming elements (Mg and Al) and impurities (Ti, Cr, Ca, P, Fe, Ni, and Gd) in the film using various X-ray emission lines (optimal accelerating voltage, etc.). The performance of the procedure was determined, and its capabilities and limitations were assessed. The resulting data on the chemical composition of the film are presented.

NIR‐II Luminescence in Cr4+ Activated CaYGaO4 toward Non‐Invasive Temperature Sensing and Composition Detection

AbstractNear‐infrared (NIR) II region (1000–1700 nm) lighting sources possess special potential for temperature sensing and quantitative composition analysis. However, it is a challenge to tune the luminescence toward such long wavelength NIR‐II emission. Herein, Cr4+ ions occupation is designed and verified in olivine‐type CaYGaO4 as [CrO4] tetrahedron by site occupancy confinement. Under 620 nm red light excitation, the phosphors display broadband NIR‐II emission centered at 1330 nm with a full width at half maximum (FWHM) of 233 nm, resulting from spin‐allowed 3T2 to 3A2 transition of Cr4+ ions in Td symmetry. The optical thermometry application is demonstrated by decoding the spectral shift and decay times varying with temperature, and the maximum relative sensitivities are 5.82% and 0.78% K−1, respectively. Furthermore, a flexible film containing CaYGaO4:Cr4+ is fabricated to implement the non‐invasive detections of fillet temperature and NH3 concentration in ammonia. This work represents a step toward developing next‐generation NIR‐II luminescence materials and widens non‐invasive detection applications.

A Robust Capillary Electrophoresis with Laser-Induced Fluorescence Detection (CE-LIF) Method for Quantitative Compositional Analysis of Trace Amino Acids in Hypersaline Samples.

The search for life in our solar system can be enabled by the characterization of extreme environments representing conditions expected on other planets within our solar system. Molecular abundances observed in these environments help establish instrument design requirements, including limits of detection and pH/salt tolerance, and may be used for validation of proposed planetary science instrumentation. Here, we optimize capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) separations for low limit of detection quantitative compositional analysis of amino acids in hypersaline samples using carboxyfluorescein succinimidyl ester (CFSE) as the amine-reactive fluorescent probe. Two methods were optimized for identification and quantification of proteinogenic amino acids, those with and those without acidic side chains, with limits of detection as low as 250 pM, improving on previous CFSE-amino acid CE-LIF methods by an order of magnitude. The resilience of the method to samples with high concentrations of Mg2+ (>4 M diluted to >0.4 M for analysis) is demonstrated on a sample collected from the salt harvesting facility South Bay Salt Works in San Diego, CA, demonstrating the highest Mg2+ tolerance for CE-LIF methods used in amino acid analyses to date. This advancement enables the rapid and robust analysis of trace amino acids and the search for biosignatures in hypersaline systems.

Application of Laser-Induced Breakdown Spectroscopy for Quantitative Analysis of the Chemical Composition of Historical Lead Silicate Glasses

The study of the chemical composition of historical glasses is widely used in archaeometry. The results of such analyses provide information on the probable date, place, and technological features of their production. Over time, a weathered layer may form on the surface of the glass, which differs in composition from the original one. To determine the initial composition using conventional methods (for example, X-ray fluorescence spectroscopy), the weathered layer should be removed. For historical objects, such manipulation is unacceptable and should be minimized. One of the methods for analyzing the chemical composition with minimal damage to a sample is laser-induced breakdown spectroscopy. The aim of this work was to develop a LIBS method, which makes it possible to perform a quantitative analysis of lead silicate glasses, including glasses containing a weathered layer. Reference glasses with a variable content of potassium, silicon, and lead oxides were synthesized, and based on the LIBS spectra, a calibration dependence was obtained that made it possible to measure the concentration of lead and potassium oxides in glasses within 70–85 and 5–20 wt%, respectively. The method was applied to analyze the composition of the glaze on a historic glazed tile from the burial church in the Euphrosinian monastery in Polotsk (the second half of the 12th century AD). The crater formed with the laser beam on the glazed surface was about 200 microns. Such damage is negligible compared to the total surface area of the tile (~10 cm2). The thickness of the weathered glaze layer was 70 microns, which was determined using variation in lead oxide content.