Éva Széles

Determination of trace elements in lithium niobate crystals by solid sampling and solution-based spectrometry methods

Solid sampling (SS) graphite furnace atomic absorption spectrometry (GFAAS) and solution-based (SB) methods of GFAAS, flame atomic absorption spectrometry (FAAS), inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) were elaborated and/or optimized for the determination of Cr, Fe and Mn trace elements used as dopants in lithium niobate optical crystals. The calibration of the SS-GFAAS analysis was possible with the application of the three-point-estimation standard addition method, while the SB methods were mostly calibrated against matrix-matched and/or acidic standards. Spectral and non-spectral interferences were studied in SB-GFAAS after digestion of the samples. The SS-GFAAS method required the use of less sensitive spectral lines of the analytes and a higher internal furnace gas (Ar) flow rate to decrease the sensitivity for crystal samples of higher (doped) analyte content. The chemical forms of the matrix produced at various stages of the graphite furnace heating cycle, dispensed either as a solid sample or a solution (after digestion), were studied by means of the X-ray near-edge absorption structure (XANES). These results revealed that the solid matrix vaporized/deposited in the graphite furnace is mostly present in the metallic form, while the dry residue from the solution form mostly vaporized/deposited as the oxide of niobium.

Sampling Strategies for Testing and Evaluation of Soil Contamination in Riparian Systems at the Tisza River Basin, Hungary

During the year 2000, two significant pollution waves came from Romanian mines to Hungary and went along the Tisza River, causing serious damage to the ecosystem of the river. The first one, cyanide pollution, at the end of January had an instantaneous effect on the living system; the second, heavy‐metal pollution in March, resulted in a long‐term effect. The heavy‐metal pollution that arrived with floods had two results. On the one hand, increased water speed decreased the grade of sedimentation in the riverbed, and on the other hand, river flooding introduced contaminated water and sediment to the floodplain. After the withdrawal of the flood, a few centimeters of grey sediment remained in the floodplain. Subsequent floods in 2000 and 2001 resuspended and diluted the contaminated sediment on the floodplain. Heavy metals (primarily lead, zinc, cadmium) deposited on the floodplain may have a potential time bomb effect. The aim of this study was to investigate the copper, cadmium, zinc, and lead contamination and bio‐availability on the floodplain applying a novel sampling strategy.

Effects of Particle Size on the Quality of Winter Wheat Flour, with a Special Focus on Macro‐ and Microelement Concentration

Abstract In countries with suitable conditions for growing winter wheat, there are millions of tons of poor‐baking‐quality wheat harvested every year. In this investigation, representative samples of low‐quality‐wheat lots were analyzed. The baking quality properties, protein, ash, and macro‐ and microelement concentrations were determined for different particle‐size fractions of flour. Flour fractions of different particle sizes sieved from the same flour samples yielded significantly different analyses for protein, ash, and macro‐ and microelements. It was determined that the particle fraction of 125–63 µm had better baking parameters than the original flour sample, and it constituted 32.5% of the total mass of the original amount of flour. In addition, the mineral‐element concentration was also found to be much higher than that of the original flour, which means that besides its better baking quality, it also had a higher nutritional value. The single, unmixed utilization of the 125‐ to 63‐µm flour fraction would mean more economic production for the baking industry and a higher value end product for the consumer. Based on our findings, we also recommend that in the chapters on materials and methods of the articles dealing with different kinds of flour, the authors should indicate the particle sizes of the flour samples analyzed because these may result in more objective evaluations of the readings.

Formation of metal selenium nanospheres in bacteria: Is it a possible detoxification mechanism?

Oil rape is a valuable fodder because in early spring and late autumn it produces green forage used for the nutrition of domestic animals. It has been replacing sunflower and soy in colder and wetter regions. It is additionally advantageous because it leaves behind more nitrogen in soil, which is beneficial to other plants in plant rotation. There are some possible ways for the fixation of nitrogen in soil and they are as follows: by the means of oil rape straw ; by relatively long roots ; by the action of nitrogen bacteria, which perform the nitrogen synthesis within their root system, which is the case in some leguminous plants. Oil seed rape is expected to be wider used in crop rotation of West and Middle Europe, Croatia included. Due to this various sorts have been introduced and potential positive impacts have been studied in order to boost the process. This paper presents information on barley and wheat yield in case when they were sown after oil seed rape and corn. The aim of the research is to determine the presence of positive impacts upon the soil with special attention paid to a potential increase of nitrogen content after oil seed rape was grown. The preceding crops had statistically significant effect. Rape yield was significantly higher compared to the one with corn as preceding crops. Very similar results were obtained in 2007.The maize hybrids seed from three different FAO groups (FAO 400, FAO 500 and FAO 600) in four fractions (KO, KP, SO and SP) produced in two climatically different years (extremely dry 2000 and extremely wet 2001) had been different in quality and chemical composition. The effects of year, genetic specifity and seed fraction at the kernel mass, chemical composition (starch, proteins, cellulose, oil and moisture content) and seed vigour have been evaluated. The influence of agroecological conditions during two production years have been exposed at seed chemical composition and vigour indicators (cold test – CT and bulk seed electrical conductivity - EC). The genetic specificity and seed fraction had significant influence at all tested indices, with the exception of the influence of the fraction at the starch content

Macro- and microelement contents of blue and red kernel corns

The role of special corns in human diets is increasing as a result of their favourable nutritional values. Little is known about mineral contents of different red and blue corns, although they may help to inhibit deficiency diseases mainly in the developing countries. During this study, mineral contents (15 elements) of 3 red and 9 blue corn varieties were examined with ICP-OES and ICP-MS. Highest contents of macroelements were as follows: P (3859.5±562.1 mg kg −1 ), K (4325.0±469.5 mg kg −1 ) and Mg (1450.0±104.6 mg kg −1 ) in the variety Black Mexican, S (1555.0±128.6 mg kg −1 ) in Santo Domingo Blue. In case of microelements, iron, zinc and selenium were highlighted. Except one genotype, iron contents were above 30 mg kg −1 . Blaumais, Hopi Turquoise and Hopi Blue contained more than 40 mg kg −1 (41.0–46.3), which were above values published in the literature (10.0 mg kg −1 in average). For zinc, we measured 15.2–31.5 mg kg −1 . Selenium contents (0.1–0.2 mg kg −1 ) were also higher than in the literat...

BOOSTER: Development of a toolbox for triage of large group of individuals exposed to radioactive material

The effective management of an event involving the exposure of a large number of people to radioactive material requires a mechanism for fast triage of exposed people. BOOSTER is a project founded by the European Union under the Seventh Framework Programme, addressing this requirement. It is a capability project designed to provide an integrated system which could easily be deployed and used. For this purpose, the BOOSTER consortium, relying on the expertise of seven members, researches and develops new approaches to allow an effective and fast management of most kind of nuclear threats. BOOSTER System was designed to help first responders mitigating the crisis by providing the necessary information to quickly assess the radiological situation, to support triage staff in performing an efficient and fast categorization of the potentially affected victims, and to give medical staff crucial information for further treatment at medium or long term post-accident.

Silver precipitation: A new and easy to use method for measuring of wheat kernel surface area

Morphology, shape and surface area of wheat kernel are important factors for the characterisation of winter wheat (Triticum aestivum) varieties in the milling industry. The surface area of kernel, due to the lack of a simple and reliable method, is not measured, but usually calculated from the length and diameter of kernel. Silver precipitation, a new original method has been developed for the measurement of kernel surface area. This method is suitable for measuring the surface of cereal seed in case of individual kernel or more kernels together. According to the silver precipitation method, metal silver was precipitated on the kernel surface. After this step the precipitated silver was dissolved from the kernel and the silver concentration in the solution was measured by inductively coupled plasma optical emission spectrometry. The concentration of silver in the solution is in close correlation with the surface area of kernel. The method was calibrated to the direct surface measurement of individual kernels and was compared to the calculated surface results.

Studying of proline content and organic contaminants in Hungarian and Greek honey samples

Introduction Honey has been used since the earliest times. It is widely appreciated as the only concentrated form of sugar available worldwide (FAO, 1996) and it also used as a food preservative (Cherbuliez, 2001; Meda et al., 2005). Therefore, honey plays an important role in our nutrition and its many positive effects on health are well-known. Unfortunately, there were some problems with quality of honey, in some case in the European Union. A dangerous acaricide (p-dichlorobenzene) was found in high concentration in Greek honey some years ago. Turn the Hungarian honey was mixed with other honey, which has low quality. These problems propose that we need a good identification system to protect the fine quality of honey. For a build-up of an applicable traceability system, it is very important to study the nutritional properties and the origin of different honey samples. In a previous paper we have shown some studied quality parameters, which can be good for a traceability system by honey (Szeles et al., 2006). Beside the mineral content, pH, HMF content, etc., it is also important to study the free amino acid content. Many studies have found analytical markers of botanical and geographical origin for honey, based on among other things the amino acid content (Anklam, 1998). Amino acids account for 1% (w/w), and proline is the major contributor with 50–85% of the total amino acids. Besides proline, there are 26 amino acids in honeys, their relative proportions depending on the honey origin (nectar or honeydew) (Hermosin et al., 2003). The content of proline is an indication of the quality of honey and is also an indication of adulteration (Meda et al., 2005). In the present study we analysed the proline content and some toxic organic materials (p-dichlorobenzene and other insecticides) in Hungarian and Greek honeytypes. The aim of this work was, first to obtain information about the proline content, as a basic quality parameter in honey and study the usability of this parameter to an identification system. Secondly, to obtain information about toxic organic material content of Hungarian but even Greek honeys. To carry out this study, 17 samples of honeys, from four different regions of Greece and also four different regions of Hungary and 5 botanical sources, were analysed.

Studying of quality parameters and organic contaminants in honey samples

Honey is valuable food for mankind since the ancient times. It was the only sweetener till the start of the industrial sugar mass production. As honey plays an important role in our nutrition and its positive effects on health is well known, it is very important to study the nutritional properties and the origin of different honey samples. The usually determined quality parameters of honey: pH values, water content, sugar content, acidity, HMF content, enzyme activity, pollen content, amino acid content, ash content, etc. It is also important to know the content of the organic contaminants in honey. A short time ago there were some quality problems with Hungarian and Greek honey in the European Union. A toxic material (para-dichlorobensene) was found in honey originated from Greece. The amount was higher than the allowable limit in the ELf. Therefore, it is necessary to build up a good and applicable traceability system for honey. During the past few years the traceability concept has become increasingly familiar in many sectors of the food industry. Traceability is an essential tool for ensuring both production and product quality. The opportunity to connect traceability with the whole documentation and control system represents an effective means for boosting the consumers perception of a foods safety and quality. In our work we have done, which quality parameters can be used for a good identification system. We have analyzed the following parameters of national and Greek honey types: mineral contents (trace elements), pH values, sugar content, acidity, HMF content, diastase activity. We have also analyzed the para-dichlorobensene in the honey samples. The samples were taken directly from Hungarian beekeepers (all professionals) and supermarkets (area of geographical origin unknown). We have measured also Greek honey. The samples were originated from some Greek islands, near Athens and from some Greek supermarkets. For the traceability it is necessary to know the following parameters: element content-free amino acids content-pollen content. Besides, it is important to analyze organic contaminants in honey.

Normalisation method for evaluation of metal contamination of soil

The yttrium normalisation method is a good tool for detection of chromium contamination in soil samples (Prokisch et al. 2000). It gives a chance to detect 5-10 times less anthropogenic chromium contamination in soil than any of the other traditional evaluation method. The principle of the normalization is the following: elements such as chromium, aluminum and yttrium exist naturally in the soil in a strongly bonded form. In a 5-9 pH range there is no leaching of these metals in the soil profile and surface. The obtained in homogeneity of these elements originates from the resuspension and migration of the small soil particles. These metals remain in the solid phase. Therefore, in a non contaminated area there is close correlation among the concentration of these elements. If the measured Cr concentration in a sample is not on the Cr-Al trend line then the distance of plotted point from the line indicates the amount of anthropogenic chromium. The aim of this study was to test the method for chromium and other elements (nickel, copper) on a land scale and a country scale resolution by the evaluation a huge dataset what was created in the laboratory in the last years. Data were used for the calculations has two origin. The first soil sample set (land scale) were taken from a 40 ha arable land applying a 50 m grid scale. The origin of the other sample set (<country scale) was the soil samples of Soil Information and Monitoring System (TIM), what is an independent subsystem of the integrated Environmental Information and Monitoring System (KIM) (V£rallyay 1995) in Hungary.