Fluorescence Analysis Method Research Articles

X-ray fluorescence analysis of chalcogenide glass with electron beam fluorescence excitation

The method of X-ray fluorescence analysis with the fluorescence excitation by an electron beam with 30 keV energy was used to determine the germanium, arsenic, and selenium content in the Ge1–xSex, As1–xSex, and Ge1–x–yAsySex glassy alloys. This technique allows determining the quantitative glass composition with an accuracy of ±0.0002 in the surface layer of a depth of ~0.1 µm from parameters x and y of the linear calibration dependences.

Possibilities of the method of an X-ray fluorescence analysis when evaluating essential element concentrations in food raw materials of plant origin

The population growth on the earth and the prospects for its increasing put forward a problem of providing clear drinking water to society and valuable fodder, food and energy resources on one of the first places every 25–30 years. The acuteness of the problem becomes more and more appreciable every year as mankind consumes the potential energy of the biosphere almost 10 times faster than its natural accumulation occurs by green plants during photosynthesis. Thus, the task of searching plant raw materials, which would become a source of biologically active substances and have positive influence on the health of animals and persons, is especially relevant today.

English

Antioxidant activities and phytochemical compounds of ethanol and hot water extracts of Agaricus bisporus species fruiting body and mycelia cultivated in Kenya were spectophotometrically determined and evaluated. The total antioxidant activity was analysed using 1,1-diphenyl-2-picrylhydrazil, hydroxyl, superoxide radical scavenging and reducing power assays, while phytochemicals were assayed through calorimetric assays. Total phenolic, β-carotene, lycopene, flavanoid and ascorbic acid composition of A. bisporus extracts was analysed by calometric assays and found to contain 40.26 to 4.61 mg/g, 48.99 to 2.86 mg/g, 67.82 to 11.87 mg/g, 93.8 to17.2 mg/g and 11.62 to 10.22 mg/g) respectively. The mineral elemental analysis done using energy dispenser x-ray fluorescence (EDXRF) analytical method revealed that the samples contain zinc (42.9 mg/l), iron (33 to 48.5 mg/l), copper (18 to 24 mg/l) and manganese (7.5 to 9 mg/l). Generally, the mycelium extracts were more effective radical scavengers than the fruiting bodies. Due to the above characteristics, A. bisporus mushroom could be considered a food complement with antioxidative activity in the diet for the health benefits they present. Their effectiveness was also evaluated by their EC50 values through interpolation from linear regression analysis of their respective data. Key words: Button mushroom (Agaricus bisporus), edible mushroom, antioxidant, reducing power, scavenging ability, phytochemicals.

A rapid and convenient method for fluorescence analysis of in vitro cultivated metacestode vesicles from Echinococcus multilocularis.

We here describe a convenient method for preparation, fixation and fluorescence analysis of in vitro cultivated metacestode vesicles from E. multilocularis. Parasite materials could be prepared in one hour, did not need to be sectioned, and were subsequently utilized for further whole-mount staining assays directly. Using these preparations, in combination with conventional fluorescence staining techniques, we could detect the expression and subcellular localization of a specific protein and identify in situ proliferative or apoptotic cells in the germinal layer of metacestode vesicles. Based on this approach, future molecular and cellular analysis of Echinococcus metacestode vesicles in the in vitro system will be greatly facilitated.

A Novel Analytical Method for Trace Ammonium in Freshwater and Seawater Using 4-Methoxyphthalaldehyde as Fluorescent Reagent.

A novel fluorescent reagent for determination of ammonium, 4-methoxyphthalaldehyde (MOPA), was successfully synthesized in this study. Under alkaline conditions, MOPA could reacted with ammonium rapidly at room temperature, producing fluorescent substance which had maximum excitation at 370 nm and emission wavelength at 454 nm. Based on this, a novel fluorescence analysis method was established for the determination of trace ammonium in natural water. Experimental parameters including reagent concentration, pH, reaction equilibrium time, and metal ions masking agent were optimized. The results showed that the optimized MOPA concentration was 0.12 g/L, pH was in the range of 11.2–12.0, and sulfite concentration was 0.051 g/L, respectively. Metal ions masking agent had no obvious effect on the fluorescence signal. With the reaction time of 15 minutes, linear range of this method was between 0.025 and 0.300 μmol/L, and the method detecting limit was 0.0058 μmol/L. The matrix recovery of the proposed method was in the range of 93.6–108.1%. Compared with the OPA method, this method was much more sensitive and rapid without the interference of background peak and would be more suitable for developing a portable fluorescence detection system.

Определение толщины гальванических покрытий Ni-P, Sn-Bi и Sn-Pb методом атомно-эмиссионной спектрометрии с тлеющим разрядом постоянного тока

Glow discharge atomic emission spectrometry allows determining the chemical composition of the coatings and their thickness as well as to conduct the depth analysis. Atomic-emission determination of the coating thickness on a single calibration curve can be performed by using the sputtering rates of coatings with different chemical composition. To realize this method the set of comparative samples with Ni-P coating was made. Samples are certified for the coating thickness by a regulated chemical, metallographic and X-ray fluorescence analysis methods. Using the atomic emission spectrometer with a dc glow discharge under optimal operating parameters, which provides a flat bottom of the crater, the calibration curve for dependence of the Ni-P coating thickness against its cathode etching was obtained. It is shown that the metrological characteristics of the current method for control of Ni-P coating thickness is not worse than the methods regulated by GOST. Samples of Sn-Bi and Sn-Pb coatings were made. The thickness of the coating was determined by the regulated methods of analysis, the optimal operating parameters of the glow discharge, which provides a flat bottom of the crater, were determined, and the absolute and relative sputtering rates of coatings in dc glow discharge were measured. Using the atomic emission calibration curve for Ni-P coating and established relative rates of sputtering, the thickness of Sn-Bi and Sn-Pb coatings was determined. It is shown that the metrological characteristics of this method are not worse than the methods regulated by GOST. Methodology for measuring the thickness of Ni-P, Sn-Bi and Sn-Pb coatings using atomic emission spectrometry with a dc glow discharge was developed and certified. Key words : atomic emission spectrometry, DC glow discharge, electroplating Ni-P, Sn-Bi and Sn-Pb, sputtering rate, operating parameters of the discharge, thickness of the coating. (Russian) DOI: http://dx.doi.org/10.15826/analitika.2015.19.1.007 A.L. Chicherskaia, A.A. Pupyshev Ural Federal University named after the first President of Russia B. N. Yeltsin, Yekaterinburg, Russian Federation

Comparison of three-dimensional fluorescence analysis methods for predicting formation of trihalomethanes and haloacetic acids

This work investigated the application of several fluorescence excitation–emission matrix analysis methods as natural organic matter (NOM) indicators for use in predicting the formation of trihalomethanes (THMs) and haloacetic acids (HAAs). Waters from four different sources (two rivers and two lakes) were subjected to jar testing followed by 24hr disinfection by-product formation tests using chlorine. NOM was quantified using three common measures: dissolved organic carbon, ultraviolet absorbance at 254nm, and specific ultraviolet absorbance as well as by principal component analysis, peak picking, and parallel factor analysis of fluorescence spectra. Based on multi-linear modeling of THMs and HAAs, principle component (PC) scores resulted in the lowest mean squared prediction error of cross-folded test sets (THMs: 43.7 (μg/L)2, HAAs: 233.3 (μg/L)2). Inclusion of principle components representative of protein-like material significantly decreased prediction error for both THMs and HAAs. Parallel factor analysis did not identify a protein-like component and resulted in prediction errors similar to traditional NOM surrogates as well as fluorescence peak picking. These results support the value of fluorescence excitation–emission matrix–principal component analysis as a suitable NOM indicator in predicting the formation of THMs and HAAs for the water sources studied.

Comparative analysis of efficiency of syngeneic and allogeneic transplantation without irradiation of the EGFP+ mice bone marrow cells with the microspectral fluorescence method

The results of experiments on syngeneic and allogeneic transplantation of the whole fraction of mice bone marrow cells without irradiation are presented. The data were obtained on the dynamic of donor cell colonization of bone marrow, spleen, thymus, and blood of the recipient mice. The degree of immunogenicity of the donor cells for both syngeneic and allogeneic transplantation of bone marrow was determined based on the method of microspectral fluorescence analysis. The low immunogenicity degree of donor cells was demonstrated for both transplantation variants within the framework of the conducted experiment. It is important to note that the allogeneic transplantation did not cause any reduction in the mean lifespan of the mice. These results, in combination with the results of our previous studies in which an increase of average lifespan by 34% was shown with syngeneic transplantation within the C57BL/6 EGFP+ strain allow one to anticipate the development of various methods of cellular therapy without risk of fatal consequences of immunological incompatibility between donor and recipient.

Effect of Solid Fuel Mineral Composition on the Formation of Sour Pulp in Hydro-Slug Removal System of Thermal Power Plants

<p>Researches have been conducted into the causes of acidity of pulp formed in the system of circulating hydraulic ash and slag removal in thermal power plants (TPP) when using coals of Ekibastuz and Karaganda coal fields of the Republic of Kazakhstan. We have carried out a comparative study of combustion of Karazhyra and Maikube coals at the two RK TPPs with BKZ-75-39FB and BKZ-160-100FB steam boilers. For ash collection, wet ash collectors with remounted Venturi tube coagulators have been installed on TPP. In them, a chemical interaction of irrigating water with flue gases occurs, which include CO<sub>2</sub>, SO<sub>2</sub>, SO<sub>3</sub> and ash particles. The ash pulp formed moves to the pipeline, mixes with the slag pulp and is further transported along a tract to the ash dump. We have defined the relationship between the composition of the products of coal combustion and the formation of acidic pulp in the scrubber. Qualitative and quantitative composition of coals and their combustion products have been determined by the methods of X-ray and X-ray fluorescence analysis. As the analysis showed, the main components of ash and slag materials are the oxides SiO<sub>2</sub>, Al<sub>2</sub>O<sub>3</sub>, Fe<sub>2</sub>O<sub>3</sub>, CaO, MgO, K<sub>2</sub>О, Na<sub>2</sub>O. In the wet ash collectors gaseous substances present in flue gases, are dissolved and hydrolysed in irrigating water. While hydroremoving ash and slag, the compounds are dissolved in water and undergo hydrolysis. Oxides SiO<sub>2</sub>, SO<sub>2</sub>, TiO<sub>2</sub>, P<sub>2</sub>O<sub>5</sub> are hydrolyzed into acid, oxides CaO, MgO, K<sub>2</sub>O and Na<sub>2</sub>O – into base, Al<sub>2</sub>O<sub>3</sub>, Fe<sub>2</sub>O<sub>3 </sub>– into amphoteric compounds. Chemical analysis of ash and slag pulp formed after Karazhyra coal combustion has been carried out. Calculation of the acidity of ash and slag material has been performed. Karazhyra coal ash is more acidic in nature. A lower content of amphoteric oxides in Maikube coal appears to be the cause of the pulp formation, with a higher pH. With X-ray diffraction method, the nature of combinations of metal oxides in the samples of coal, slag and ash have been determined. </p>

Fluorescent Properties of Cancerous Liver Tissue

Fluorescence spectroscopy is a technology used fruitfully for biomedical diagnostics as well as for therapeutic purposes. The fluorescent analysis method are applied in biomedical diagnosticsbases on fluorescence of endogenous or exogenous fluorophores. We initially applied fluorescence spectroscopy for the study of human liver cancer (hepatocellular carcinoma) with an exogenous fluorophores, Radachlorin\(^{\circledR }\) 0.35%. The main aim of this study is to determine the spectral variation between normal and malignant liver tissues in 2 cases: the samples expose and non-expose to Radachlorin. The excitation wavelength used for the fluorescence measurements is 405 nm.

Determination of Gentamicin Residual in Duck Meat Using Fluorescence Analysis Method

Gentamicin is a kind of aminoglycoside antibiotics and widely used in the prevention and treatment of the duck diseases. A prediction model was established for the rapid detection of Gentamicin residue in duck meat using fluorescence analysis method according to the strong fluorescent characteristic of the generated derivative for Gentamicin and o-phthaldialdehyde (OPA) in the presence of emulsifier OP-10 and mercaptoethanol.The fluorescence spectra of the duck meat containing Gentamicin were analyzed, the optimum excitation wavelength of the material was 340 nm and the optimum emission wavelength was 442 nm. Fluorescence intensity and the concentration of the standard samples presented the good linear relationship, the linear correlation coefficient was 0.9963 and the limit of detection was 0.47 μg/mL in the dynamic rang of 0.5 ~6.5μg/mL. The correlation coefficient of regression equation was 0.9968 for the samples of duck meat extract. The experimental results showed that the fluorescence analysis method had a good performance and accuracy in detecting the Gentamicin residue in duck meat.

Recognition Kinetics of Biomolecules at the Surface of Different-Sized Spheres

Bead-based assay is widely used in many bioanalytical applications involving the attachment of proteins and other biomolecules to the surface. For further understanding of the formation of a sphere-biomolecule complex and easily optimizing the use of spheres in targeted biological applications, it is necessary to know the kinetics of the binding reaction at sphere/solution interface. In our presented work, a simple fluorescence analysis method was employed to measure the kinetics for the binding of biotin to sphere surface-bound FITC-SA, based on the fact that the fluorescence intensity of FITC was proportionally enhanced by increasing the binding amount of biotin. By monitoring the time-dependent changes of FITC fluorescence, it was found that the binding rate constant of biotin to sphere surface-immobilized FITC-SA was much smaller than that of biotin to freely diffusing FITC-SA. This can be attributed to the decreased encounter frequency of the reaction pair, restricted motion of the attached biomolecule, and the weakened steric accessibility of the binding site. These factors would become more obvious when increasing the size of the sphere upon which the FITC-SA was immobilized. Additionally, the effect of nanoparticles on the diffusion-controlled bimolecular binding reaction was more evident than that on the chemical recognition-controlled binding reaction.

An improved method for fluorescence analysis of dissolved organic matter in cave drip water

An improved synchronous fluorimetric method for the determination of dissolved organic matter in cave drip water, by adding ascorbic acid, is described. The method is based on the redox reaction between ascorbic acid and the electron-withdrawing constituents in dissolved organic matter. The results show that adding ascorbic acid can quench the minor peaks, at 200–300 nm, but does not affect the intensity of the main peaks at 300–500 nm. In addition, adding ascorbic acid can maintain relatively high and constant fluorescence intensity over a wide pH range (9-4).

Nuclear-physical analysis of the contamination on the surface of a COMPLAST panel after 12-year exposure at the ISS

Using methods of X-ray fluorescence analysis (XRFA), the Rutherford backscattering of ions (RBS) and spectral X-ray microanalysis (SXRM) in combination with scanning electron microscopy (SEM), we study the elemental composition and structure of contaminants on the surface of a metallic panel with samples of different materials exposed to outer space for 12 years. It turns out that the main elements of the contaminants are C, O, Si, S, Ca, Fe, and Zn. Since these elements are the constituents of materials located on the panel, they are present as a result of destruction of the materials under the action of outer-space factors. X-ray phase analysis (XRPA) of the contaminants shows that carbon is present in the form of an amorphous graphite phase with a small addition of crystalline graphite, while the other components are in an amorphous state. Crystalline silicium dioxide and other silicium compounds are not found.

Flotation, Filtration, and Adsorption: Pilot Trials for Oilfield Produced-Water Treatment

Summary As an oil field matures, it produces larger quantities of produced water. Appropriate treatment levels and technologies depend on a number of factors, such as disposal methods or usage aims, environmental impacts, and economics. In this study, a pilot plant with a capacity of 50 m3/day was used to conduct flotation, filtration, and adsorption trials for produced-water treatment at a crude-oil gathering facility. The flexible design of the plant allows for the testing of different combinations of these processes on the basis of the requirements of the water to be treated. The subject water during this study was a complex and changing mixture of brine and oil from different oil fields. Induced-gas-flotation (IGF) trials were conducted, with different coagulant [poly-aluminum chloride (PAC)] -addition rates from 0 to 820 mg•L-1. Inlet-dispersed oil-in-water (OIW) concentrations were quite varied during the trials, ranging from 39 to 279 mg•L-1 (fluorescence-analysis method). Turbidity also varied, ranging from 85 to 279 FTU. Through coagulation/flocculation and flotation, dispersed oils were removed from the water. PAC addition ranging from 60 to 185 mg•L-1 resulted in the reduction of the dispersed-oil concentration to less than 50 mg•L-1 in treated water; and PAC addition ranging from 101 to 200 mg•L-1 resulted in the reduction of the dispersed-oil concentration to less than 15 mg•L-1 in treated water. Turbidity was also reduced through flotation, with trial average reductions ranging from 57 to 78%. Filtration further reduced turbidity at rates greater than 80% through the removal of any suspended solids remaining from flotation. Activated-carbon adsorption reduced OIW concentrations of flotation-/filtration-treated water to 5 mg•L-1 (infrared-analysis method) through the removal of dissolved oil remaining in the water. Results confirmed that such adsorption treatment would be more practical for water with lower chemical-oxygen-demand (COD) concentration because high-COD concentrations in water reduce the lifetime of activated carbon dramatically.

An stable approach to a kind of problems involving the inversion of a Volterra integral equation of the first kind: application to x-ray fluorescence analysis

In some physical problems it is necessary to obtain a function coming from the inversion of an unstable problem, and use it to calculate some global quantities by integrating it weighted by the appropriate weighting functions. When the desired function comes from a first kind Volterra integral equation, the explicit inversion can be avoided by integrating by parts in the integrals in which the above mentioned function appears. That is the case of the fundamental parameters method of x-ray fluorescence analysis. To obtain the concentrations of chemical elements in the sample which is analyzed it is necessary to calculate some integrals of the spectral distribution of the fluorescence exciting x-ray beam multiplied by a weighting function which depends on the concrete analysis to be done. The spectral distribution of the fluorescence exciting beam is related to the experimental measurements of the fluorescence excited on a set of targets made up of pure elements by a Volterra integral equation of the first kind, and it can be obtained by inverting the Volterra equation. By integrating by parts in the integrals in which the spectral distribution appears we avoid the unstable reconstruction of the spectrum of the fluorescence exciting x-ray beam and the concentrations can be calculated in a stable fashion.

Clusters Formation in Salts Solution in Polar Dielectric Liquids and Electrically-induced Separation of Solvated Ions

The aim of study is to demonstrate that separation of solvated ions in solution of mix of salts under the action of external periodic electric field happens because of around ions there are formed clusters consisting of molecules of solvent and the sizes of such clusters have dimensions ~ 0.1 μm. In investigations the sizes of clusters theoretically were defined and experimentally value of frequency of external electric field which action excites the effect of separation of the solvated ions was defined. Experiments were done in the Technical Physics Chair of the National Research Tomsk Polytechnic University. At theoretical determination of the dimensions of clusters Poisson's equation was solved and was considered that polar molecules of solvent are oriented under the action of electric field of an ion. The chemical composition of samples of solutions was determined by means of the X-ray excited fluorescent radiation analysis method. Theoretical estimates and results of experiments confirmed the assumption that clusters which are formed around ions in solutions have the dimensions ~ 0.1 μm. Results of investigation testify that placing of volume distributed electric charge of ion in Original Research Article British Journal of Applied Science & Technology, 4(18): 2014 2539 dielectric liquid is accompanied by formation of the supramolecular particles, which we called “clusters”, linear sizes of which is significantly more than first and second radiuses of solvation (~ 1 Angstrom) and reach size ~ 0.1 μm. At such sizes inertial properties of clusters and their natural frequencies give the chance to operate their movement by means of action of external electric field on solution.

Quantitative X-ray fluorescence analysis of multielemental subjects of complex shape without implementation of reference standards

A theoretical dependence of the ratio of intensities of X-ray fluorescence lines of chemical elements on the ratio of their concentration in a sample is suggested. The effect of various experimental factors on parameters of the obtained model is considered. A method of quantitative X-ray fluorescence analysis of multielemental subjects using the suggested calibration dependence without the implementation of reference standards is described. The adequacy and analytical advantages of the developed approach are demonstrated for the determination of the elemental composition of a sample of a metal alloy of complex shape.

Prospects of using the method of X-ray fluorescence analysis as a method of control of microelement balance in patients with diffuse alopecia

The possibility of using the method of X-ray fluorescence analysis to assess the bioelemental status of the human organism of people with diffuse alopecia is shown. In modern conditions of life support the increase level of ecological discomfort of the environment exeeds the potential protection capacity of the body and leads to the stress and disruption of adaptation with all that it implies, in some cases, it is expressed as alopecia.

Pharmacognostic studies of insect gall of Quercus infectoria Olivier (Fagaceae)

ObjectiveTo study the detailed pharmacognostic profile of galls of Quercus infectoria Olivier (Q. infectoria olivier) (Fagaceae), an important medicinal plant used in the Indian system of medicine. MethodsSamples of galls of Q. infectoria were studied by macroscopical, microscopical, physiochemical, phytochemical, fluorescence analysis and othjer methods for standardization as recommended by WHO. ResultsMacroscopically, the crude drug is globose with horny appearances on external surface (1.4–2.3 cm in length and 1–1.5 cm in diameter), with greyish-brown to brownish-black in colour externally and dark brown buff colored. Surface is smooth with numerous horny protuberances giving rough touch, and with unpleasant odour. Microscopically, a wide zone of radially elongated parenchyma cells between upper and lower epidermis were found. The vascular strands were present at all places and radially elongated sclerides touched the lower epidermis. In physico-chemical studies, the moisture, total ash, acid insoluble ash, alcohol soluble, water soluble, petroleum ether, chloroform extractive value and tannin content were found to be 2.790, 5.020, 0.110, 38.780, 41.210, 0.402, 1.590 and 49.200 percentage respectively. Preliminary phytochemical screening showed the presence of phenols, flavonoids, steroids, triterpenes, tannins, saponins and alkaloids. ConclusionsThe results of the present study serve as a valuable source of information and provide suitable standards for identification of this medicinally important plant drug material for future investigations and applications.