Chemical Characterization of Airborne Particles in St. Martinus Cathedral in Weert, The Netherlands

Electron probe X-ray microanalysis (EPMA) of single particles and energy dispersive X-ray fluorescence analysis (EDXRF) were applied to determine the chemical composition, size and probable origin of the suspended particulate matter. The aim of the performed research was to determine the chemical composition, size and abundance of aerosol particles responsible for blackening and soiling of the works of art displayed within the Cathedral of Weert in the Netherlands and to verify the possible sources responsible for these processes.     

Determination of Phenolic Compounds and Coumarins in Sugar Cane Spirit Aged in Different Species of Wood

The identities and quantities of the phenolic compounds and coumarins in twelve samples of sugar cane spirit aged in Quercus sp., Amburana cearensis, Cariniana legalis, Castanea sativa Mill, Ocotea sp., Cotyledon orbiculata L., and Hymenaea sp. casks were determined. These compounds have a direct influence on the sensory characteristics of aged beverages; some of them are considered to be markers for the aging process. The analysis of phenolic compounds was performed by HPLC. Solid phase extraction (SPE) was also used for the determination of coumarins. The concentrations of the principal compounds extracted varied according to the species of wood. The concentrations of total phenolic compounds ranged from 0.08 for a sample stored in a 4000-L jatobá barrel for a period of six months to 40.9 mg · L^?1 for a sample aged in a 50000-L oak barrel for a period of 48 months. The use of the SPE technique removed interfering compounds from the samples, thereby improving the detection of coumarin.     

超高效液相色谱法测定甘蔗和土壤中敌草隆残留

建立了一种测定甘蔗和土壤中敌草隆农药残留的超高效液相色谱(UPLC)方法.样品经水和甲醇提取,二氯甲烷液-液分配后,过中性氧化铝柱纯化,用石油醚:乙酸乙酯的混合液(体积比85:15)淋洗和洗脱,洗脱液经减压浓缩后用5 mL乙腈定容.采用UPLC分离,紫外检测器检测,外标法定量.敌草隆在0.02～5.0 mg/L范围线性...     

Study of the winter and summer changes of the air composition in the church of Szalowa, Poland, related to conservation

The St. Michael Archangel’s Church in Szalowa, Poland, was selected for closer investigation with respect to the indoor/outdoor air exchange and its influence on the air quality and work arts preservation. Chemical composition, size and abundance of particulate matter and concentration of gases NO₂, SO₂, O₃ inside and outside the church were determined. To study seasonal variation of the weather condition (temperature, inversion level, wind direction) and the influence of seasonal sources of the air pollution (like heating of the nearby houses), samples were collected in winter and summer time. It was stated that suspended particulate matter inside the wooden church has in general an outdoor source. Several groups of particles were distinguished such as the organic ones, soil dust, nitrates and sulphates. In case of organic and soil dust particles, the concentration inside was higher than outside. From the results, in comparison to literature data, one can conclude that accumulation of particulate suspended matter in the church is more intense than in other types of buildings. Gaseous pollutants were detected but their concentration was negligible.     

Light Element Analysis of Individual Microparticles Using Thin-Window EPMA

 The determination of the concentration of light elements, such as carbon, nitrogen and oxygen, in e.g. atmospheric aerosol particles is important to study the chemical behaviour of atmospheric pollution. The knowledge of low-Z element concentrations gives us information on the speciation of nutrients (species having nutritional value for plants) and toxic heavy metals in the particles. The capability of the conventional energy-dispersive EPMA is strongly limited for the analysis of low-Z elements, mainly because the Be window in the EDX detector hinders the detection of characteristic X-rays of light elements such as C, N, O and Na. WDS is suitable for analysis of light elements, but the measurement of beam sensitive microparticles requires the minimisation of the beam current and the measurement time. A semi-quantitative analytical method based on EPMA using an ultra-thin window EDX detector was developed. It was found that the matrix and geometric effects that are important for low-energy X-rays can be reliably evaluated by Monte Carlo calculations. Therefore, the quantification part of the method contains reverse Monte Carlo calculation done by iterative simulations. The method was standardised and tested by measurements on single particles with known chemical compositions. Beam-sensitive particles such as ammonium-sulphate and ammonium-nitrate were analysed using a liquid nitrogen cooled sample stage. The shape and size of the particles, which are important for the simulations, were determined using a high-magnification secondary electron image. Individual marine aerosol particles collected over the North Sea by a nine-stage Berner cascade impactor were analysed using this new method. Preliminary results on five samples and 4500 particles show that the method can be used to study the modification of sea-salt particles in the troposphere.     

Application of EDXRF and Thin Window EPMA for the Investigation of the Influence of Hot Air Heating on the Generation and Deposition of Particulate Matter

This paper presents a systematic micro-analytical study for the assessment of the influence of a typical hot-air blow-in heating system on the generation, transport and deposition of suspended particulate matter (SPM) in the church of Rocca Pietore (Italian Alps). This kind of heating system is very popular in cold regions due to its fast response and economic properties. The size, chemical composition and abundance of individual particles responsible for the negative impact on the displayed artworks are determined by ultra-thin window EPMA. EDXRF is used to determine the bulk chemical composition of SPM. Some gaseous pollutants (SO₂, NO₂ and O₃) are sampled with the application of passive diffusion tubes and quantified with ion-chromatography and spectrophotometry. It is pointed out that several deterioration processes, such as the abrasion of the plastered walls, the re-suspension of the particulate pollution and the generation of NO₂ gas, arise mainly from using the heating system. Each of these observations is a concern for the preservation of the displayed works of art.     

Application of Thin-Window EPMA to Environmental Problems in Hungary

 The combination of single-particle analysis using thin-window EPMA and a reverse Monte Carlo quantification procedure has been proven to provide semi-quantitative elemental concentrations, including light elements. The capabilities of the method are demonstrated through three different environmental applications in Hungary. Lake Balaton is the largest lake in central Europe. It is suspected that the atmosphere is an important source of environmental deterioration of the Lake, relative to the pollutant supply by rivers and direct discharges. Thin-window EPMA results of around 25,000 individual particles indicated that the composition of the aerosol did not show characteristic seasonal variation, it was more correlated to the daily meteorological circumstances. A serious heavy metal pollution of the river Tisza occurred on 10 March 2000, from a mine-dumping site in Romania. Sediment samples were taken from the main riverbed at six sites, on 16 March 2000. In some of the samples, pyrite type particles were observed in high abundance, revealing their dumping-site origin. Biomass burning for energy production has been increased recently, mostly in households and for space heating. Fly-ash and bottom-ash samples were collected at a 600 kW heating plant at Sződliget during standard winter operation. Most particles contained over 65% of unburned organic substance. The concentrations of major elements were obtained for each individual particle using thin-window EPMA, providing accurate matrix composition for further μ-XRF investigations of the trace element composition.     

Flow Injection Piezoelectric Determination of Brix in Sugar Cane Juice and in the Alcoholic Fermentation Process

Abstract

A flow injection piezoelectric procedure is proposed for the determination of brix (total solids dissolved) in the alcoholic fermentation process. A piezoelectric Perspex cell was constructed to fit one of the gold electrodes of a 10 MHz crystal and this sensor was adapted to a flow injection system. The analytical curve is linear over the brix range from 0.5 to 20.0% with a detection limit of 0.3%. Seventy results can be obtained per hour and the relative standard deviation was less than 1.45% for a solution containing 6% of brix (n=15). Applications of this method for the determination of brix in sugar cane juice and in an alcoholic fermentation bench show satisfactory results in comparison with refractometric and densimetric methods, respectively.     

Fission Gas Bubbles Characterisation in Irradiated UO2 Fuel by SEM, EPMA and SIMS

The behaviour of gases produced by fission is of great importance for nuclear fuel operation. Within this context, an experimental method for the characterisation of the fission gas including gas bubbles in an irradiated UO₂ nuclear fuel was developed in our laboratory using SIMS, EPMA and SEM results. SIMS and EPMA have been used to measure the radial distribution of xenon and SEM gives information on bubble formation across the fuel pellet radius. Using SIMS, xenon concentration can be determined in the matrix and in the bubbles. A quantification method, allowing the determination of the total inventory of xenon, is proposed and qualified with EPMA results. It is concluded that the complementary micro-analytical techniques SIMS, EPMA and SEM are very powerful tools for the characterisation of the fission gas bubbles in irradiated nuclear fuel.     

Assessing the size-dependent chemical speciation of soil particles using electron probe X-ray microanalysis

Soils of the Pereemnaya river catchment, East Siberia, Russia, characterized by high percentage of particles under 10 μm size and the almost total absence of clay minerals, were studied using ultra-thin window electron probe X-ray microanalysis (EPMA). Three subfractions – 10–5 μm, 1–5 μm and <1 μm were distinguished within <10 μm fraction on the basis of mineralogical composition and chemistry peculiarities. Besides the single particles characterization, the bulk chemistry of specified subfractions and their contributions to the bulk soil chemistry were evaluated. It was shown that concentrations of alkali and alkaline-earth metals within <10 μm fraction increased in the row (5–10 μm) < (1–5 μm) < (<1 μm). The presence of two mica types – low-Fe and rich-Fe – was detected in all the subfractions. Being compared with the soil bulk chemistry, the data obtained for fraction <10 μm show that this fraction is the major source of alkali and alkaline-earth metals and consequently the main contributor to element release due to weathering.     

A seasonal study of atmospheric conditions influenced by the intensive tourist flow in the Royal Museum of Wawel Castle in Cracow, Poland

Increasing mass tourism can generate important microclimatic perturbations and also elevate indoor pollution by the transport of fine particulate matter. The purpose of this research was to study the indoor air conditions in the Royal Museum of Wawel Castle in Cracow, Poland, displaying amongst other valuable works of art also a unique collection of Flemish tapestries. The investigation involved in the determination of transport and deposition of particulate matter brought in by visitors. The microclimate inside the exhibition rooms was also monitored. Samples of suspended particulates were collected inside and outside the museum in winter and summer 2006. On days with intensive tourist visits the concentration of total suspended particulates was significantly higher (i.e., 130 µg/m³ in winter and 49 µg/m³ in summer) than on those days without tourists (i.e., 73 µg/m³ and 22 µg/m³ in winter and summer, respectively). The concentrations of all investigated elements were also considerably higher during the tourist flow. This was especially valid for soil dust associated elements (Si, K, Ca, Al, and Ti), with considerably higher levels in summer than winter. This could be linked with much more frequent tourist activity in the summer period. Also, the concentration of Cl was much higher in winter than summer, due to the use of de-icing salts on the roads and pavements.     

Determination of Nb, Ta, Zr and Hf in Micro-Phases at Low Concentrations by EPMA

 Depletion of high field strength elements (HFSE: Nb, Ta, Zr, Hf ) relative to other lithophile trace elements in arc magmas and variations of Nb/Ta and Zr/Hf ratios in mantle-derived rocks can be addressed through studies of minerals, which concentrate and fractionate these elements. The presence of rutile, a common accessory Ti-oxide phase in various mantle rocks, has often been invoked to explain the Nb and Ta depletion in arc lavas because it has the highest HFSE abundances among the known mantle minerals. In this study, we measure the concentrations of Nb, Ta, Zr and Hf (at > 200 ppm) in rutile of two metasomatized mantle lherzolites using a Cameca SX-100 electron microprobe and obtain Nb/Ta ratios with an accuracy of about ± 5%. Mass balance calculations indicate that ≤ 1−5% of Nb and Ta in the rocks reside in major minerals and that the balance is hosted by accessory Ti-oxides. The Nb/Ta ratios vary significantly in nearby rutile grains in both peridotites (17–33, average 23; 12–37, average 21). Therefore, individual rutile grains may not be representative of the total grain population. However, Nb/Ta ratios measured in the bulk rock lherzolites by solution ICP-MS (21 ± 0.3) are within the analytical error of the average Nb/Ta values calculated for 5–7 rutile grains in both samples. These results emphasise that a representative grain selection must be analysed in order to determine trace elements contents of bulk rocks from data on accessory phases.     

Microanalysis of Hydrogen, Boron and Fluorine in Vesuvianite by Means of SIMS, EPMA and FTIR

Vesuvianite, a complex sorosilicate, often contains variable (from trace-to-minor-element) amounts of H, B and F. We describe a microanalytical study of H, B and F in vesuvianite by means of Electron Probe Microanalysis (EPMA), Secondary Ion Mass Spectrometry (SIMS), and single-crystal Fourier-Transform InfraRed (FTIR) spectroscopy. Most crystals investigated are B- (up to 3.67 wt% B₂O₃) and F-rich (up to 2.38 wt%); H₂O ranges from 0.243 to 0.665 wt%. The H data obtained by SIMS allowed us to calibrate the quantitative analysis of H₂O by FTIR spectroscopy. The resulting molar absorption coefficient (ɛ _i = 100 000 ± 2000 L · mol⁻¹ · cm⁻²) is in excellent agreement with working curves available from the literature. Moreover, the SIMS data allowed us to obtain the calibration curve to estimate the B₂O₃ content on the basis on the FTIR absorbance: a _i = 34000 ± 1400 · B₂O₃ (wt%).     

Regeneration of Q-State PbS Particles in Langmuir-Blodgett Films

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Analysis and Comparison of Aroma Compounds of Brown Sugar in Guangdong,Guangxi and Yunnan Using GC-O-MS

Guangdong, Guangxi and Yunnan are the three provinces in China that yield the most brown sugar, a brown-red colored solid or powdered sugar product made from sugar cane. In the present study, the differences between odor compounds of brown sugar from Guangdong, Guangxi, and Yunnan provinces in China were compared and analyzed by gas chromatography-olfactometry-mass spectrometry (GC-O-MS). A total of 80 odor compounds, including 5 alcohols, 9 aldehydes, 8 phenols, 21 acids, 14 ketones, 5 esters, 12 pyrazines, and 6 other compounds, were detected. The fingerprint analysis of the brown sugar odor compounds showed 90% similarity, indicating a close relationship among the odor properties of brown sugar in each province. Moreover, the orthogonal partial least squares discriminant analysis (OPLS-DA) was performed to identify the compounds contributing to the volatile classification of the brown sugar from three provinces, which confirmed that OPLS-DA could be a potential tool to distinguish the brown sugar of three origins.     

Arsenic Speciation in Plant Samples from the Iron Quadrangle, Minas Gerais, Brazil

Several plants, especially ferns, have been shown to tolerate and accumulate high arsenic concentrations in soils. The leaves and roots of the ferns Pteris vittata (Chinese brake) and Pityrogramma calomelanos as well as a medical plant (Baccharis trimera) were sampled together with their associated soils in a region impacted by ore mining, the Iron Quadrangle in Brazil, where arsenic concentrations in the soils vary sharply (6–900 μg g⁻¹). The bioaccumulation factors were found to be low compared to the literature data, which can be explained by the low water-soluble fraction of arsenic in soil. The arsenic species in the plants were mainly arsenite. In comparison to the rhizoid samples, the concentrations of arsenic were higher in the leaves of the fern samples. The medical plant behaved differently. The bioaccumulation factor was low (0.7), and trimethylarsine oxide was detected as the third arsenic species beside arsenite and arsenate in both the roots and the leaves.     

The Corrected Value of the Y La Mass Absorption Coefficient in Silicon

In earlier experiments some irregular effects were observed in the X-ray spectra of yttrium doped -sialon ceramics. Yttrium L was totally absorbed whereas yttrium K was present in the spectra. Since the only reasonable explanation for these observations seems to be the effect of the silicon K-absorption edge on the entire absorption of the Y L, the experimental determination of the Y L mass absorption coefficient (mac) in silicon was performed. The silicon layer has been deposited by thermal vacuum evaporation simultaneously on the surfaces of the silica glass plate, the nickel plate and on the polished surface of the yttrium oxide sample. The silicon-covered silica glass plate was used for the layer thickness measurements (interference microscope). The silicon layer on the nickel plate was employed in the measurements of the Ni L mac value in silicon in order to verify the correctness and accuracy of the methodology. The yttrium L intensities were then measured at the silicon covered and uncovered parts of the yttrium oxide sample surface. The measured intensities were corrected with respect to the primary electron backscattering in silicon and their energy reduction in the layer. Typical EPMA instrumentation was used in all measurements. The value of the yttrium L mass absorption coefficient in silicon computed on the basis of the Lambert-Beer law appeared to be not lower than 7100 [cm²g^–1] against the value of about 3255 [cm²g^–1] reported in X-ray tables.     

Advances in Electron Backscatter Diffraction for the Characterisation of Interfaces

This aper describes state-of-the-art analysis of grain boundary populations by EBSD, with particular attention paid to advanced, non-standard analysis. The capability and versatility of EBSD for the characterisation of interfaces is emphasised. The discussion is focussed on boundaries in face-centred cubic metals, since the majority of work has been carried out on this subset of materials. Data processing based both on misorientation alone and customised additions which include the boundary planes are described. Although commercial EBSD packages offer data processing options for interfaces, it is clear that there is a wealth of more in-depth data that can be gleaned from further analysis. In particular, determination of all five degrees of freedom of the boundary population provides an exciting opportunity to study grain boundaries by EBSD in a depth that was hitherto impossible.     

The Use of SIMS, SEM, EPMA, LRS and X-Ray Diffraction Measurements for the Examination of Corrosive Layers and Protective Coatings on Steels and Alloys in Advanced Power Stations

The development of modern power generation systems with higher thermal efficiency requires the use of constructional materials of higher strength and improved resistance to the aggressive service atmospheres. In this paper the following examples are discussed:1) The oxidation behaviour of 9% (w/w) Cr steels in simulated combustion gases: the effects of O₂ and H₂O content on the oxidation behaviour of 9% (w/w) Cr steels in the temperature range of 600–800°C showed that in dry oxygen a protective scale was formed with an oxidation rate controlled by diffusion. However, in the presence of water vapour, after an incubation period, the scale became non-protective as a result of a change in the oxidation mechanism.Oxidation experiments on 10% (w/w) Cr steel in simulated steam atmosphere at 650°C have shown that a haematite layer is formed. The investigation suggests that several independent processes, such as oxide dissociation and solid state diffusion of iron cations in the scale, significantly contribute to the overall oxide growth process.2) The development of light-weight intermetallics based on TiAl-basis: TiAl-based intermetallics are promising materials for future turbine components because of their combination of high temperature strength and low density. These alloys, however, exhibits poor oxidation resistance at temperatures above 700°C. The experimental results showed that the oxidation behaviour of TiAl-based intermetallics can be significantly improved by minor additions of 1–2 at-% silver.     

Determination of Iodine in Enriched Chlorella by ICP-OES in the VUV Region

A method of determining iodine in the vacuum ultraviolet region by inductively coupled plasma optical emission spectrometry in enriched Chlorella is established and evaluated. Alga Chlorella samples enriched with iodine were solubilized with tetramethylammonium hydroxide. The iodine content was quantified by inductively coupled plasma optical emission spectrometry using the 182.980nm emission line of iodine to avoid the spectral interference from phosphorus which occurs in Chlorella at the 178.218nm emission line of iodine. The methods accuracy was confirmed by a modified Sandell and Kolthoff spectrophotometric method (As³⁺, Ce⁴⁺ and brucine) after alkaline ashing, and the agreement between the methods was about 96%. The limit of detection in real samples was 3mgkg^–1 for enriched Chlorella, and the iodine content in the samples varied between 100 and 1300mgkg^–1.