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Validation of analytical methods for measurements of microplastics (MP) is severely hampered because of a general lack of reference materials, RM. There is a great need to develop such reference materials. This study presents a concept of three-component kit with immobilised MP in solid NaCl, a surfactant and clean water that can be applied for the production of many types of MP RMs. As proof of concept, an RM for polyethylene terephthalate (PET) particles in water was prepared and evaluated for its homogeneity. The particles ranged from 30 μm (Feretmin) to about 200 μm adapted by wet sieving. A specific number of PET particles were immobilized in about 0.29 g of solid NaCl by freeze-drying 1 mL of a NaCl suspension. By using manual and automated counting, twenty reconstituted 1-L water samples were evaluated for homogeneity with respect to number of PET particles from 30 μm to > 200 μm/L of water. The number of particles was 730 ± 120 (mean ± one standard deviation (SD); n = 10) and 865 ± 155 particles (n = 10) obtained by optical microscopy in two independent laboratories. This corresponded to relative SDs of 16.4 and 17.9% and a mean of 797 ± 151 particles (18.9% RSD, for n = 20). Homogeneity studies of the NaCl carrier without reconstitution resulted in 794 ± 60 particles (7.5% RSD). The homogeneity of PET in the salt carrier was also evaluated directly with respect to mass of PET per vial using an ultra-micro balance. An average mass of 293 ± 41 μg of PET was obtained (14, % RSD for n = 14). Micrographs were recorded to demonstrate the absence of major sources of contamination of the RM components. Information about the particle size distribution and particle shapes was obtained by laser diffraction (LD) and dynamic image analysis (DIA). In addition, the identity of the PET polymer was confirmed by Raman and FT-IR spectroscopy. The RM was developed for a large-scale inter-laboratory comparison of PET particles in water (ILC). Based on the homogeneity results, the material was found to be sufficiently homogeneous to be of meaningful use in the ILC. In a 3-day process, more than 500 samples of PET particles in the NaCl carrier were prepared with good potential for further upscaling with respect to the number of vials or with other kinds of polymers. The stability of PET was not evaluated but it was deemed to be stable for the duration of the ILC.

Historical buildings and castles that have been turned nowadays into museums, as an exhibition area for precious cultural heritage (CH) items, need more attention since they are CH objects by themselves. Moreover, the preservation techniques require often, significant interventions; however such changes are not always possible or are very limited. The aim of the present study was to investigate the influence of outdoor air pollution on the composition of particulate matter and gases inside the museum of Wawel Castle in Cracow, Poland. During this study a combination of micro and trace analysis techniques were applied, including energy dispersive X-ray fluorescence (EDXRF) and electron probe microanalysis (EPMA). An intensive transport of air pollutants coupled with accumulation of the particles inside the museum was noticed (considerably higher in winter than summer). A high content of carbon and organic matter agglomerated with inorganic particles was determined. Those particles are of special concern because of their adhesive properties and reactivity. It was also noted that the conditions inside the museum favour the reaction of the particles with gaseous pollutants. It was especially the case for nitrate particles.

The molecular character of atmospheric particulate matter is of prime importance when interpreting air pollution trends and its subsequent influence on environmental monitoring and preventative conservation. The known methods of estimating the molecular composition normally involve elemental analysis of particles (both as bulk and computer controlled analyses of single particles) with subsequent multivariate analyses to clusterise the elements in groups of elements that are closely related to each other. With this approach one can at best suggest associations. Evidently the application of molecular spectroscopy in addition to elemental concentration profiles would provide intimate information regarding the nature of the particles and consequently their fate. This paper gives an overview of research performed in our laboratory and describes the optimisation of experimental parameters to use scanning electron microscopy with energy-dispersive X-ray detection (SEM/EDX) or electron probe X-ray microanalysis (EPXMA) in parallel with micro-Raman Spectrometry (MRS) to investigate single environmental particles. The challenges associated with the two stand-alone techniques are revealed and consequently those posed with an interfaced approach are discussed. Preliminary results, of an initial investigation of the SEM/EDX interfaced with MRS to ultra-fine heterogeneous environmental particles, are given.

As swipe samples from enrichment activities typically contain uranium particles with a detectable amount of fluorine, the question was raised whether the analysis of fluorine in particles could complement the information on the uranium isotope ratios. For this, uranium oxyfluoride particles were prepared from the controlled hydrolysis of uranium hexafluoride (UF 6 ). The relative amount of fluorine was characterized by scanning electron microscopy combined with energy-dispersive X-ray spectrometry (SEM-EDX), as well as ion-microprobe secondary ion mass spectrometry (IM-SIMS). Of particular interest was the assessment of the reduction of the amount of fluorine over time, and after exposure to UV-light and high temperatures. Micro-Raman spectrometry (MRS) was applied to look for differences in molecular structure between these various sample types. Both SEM-EDX and IM-SIMS showed a general reduction of the fluorine-to-uranium ratio after 1–2 years of storage. The exposure to UV-light and high temperatures was found to have accelerated the loss of fluorine. A distinct peak at 865 cm − 1 Raman shift was detected for the majority of particles analyzed by MRS. For the particles that were heat-treated, the Raman spectra were similar to the spectrum of U 3 O 8 . Although often large variations were observed between particles from the same sample, the three particle measurement techniques (IM-SIMS, SEM-EDX and MRS) showed some consistent trends. They therefore appear promising in terms of the ability to place bounds on particle age, as well as shedding light on the complex processes involved in UO 2 F 2 particle ageing.

This paper describes results of applying the palynological and carbon isotopic analysis of the organic fraction of Total Suspended Particles (TSP) to discriminate distinct pollution sources and assess the anthropogenic impact for the investigated areas. The samples of atmospheric particles were collected in Czerniawa and Cieplice (two health resorts in Lower Silesia, SW Poland) twice a year in summer and winter season (from July 2006 to February 2008). The palynological spectra represent in the vast majority local plant communities without a noticeable contribution of long-transported plant particles. Palynological analysis revealed also differences in the specificity of the two sampling areas, i.e. the higher contribution of identified organic material in Czerniawa stands for more natural character of this site, but is also responsible for the higher allergic pressure when compared to Cieplice. The carbon isotopic composition of TSP varied seasonally (δ13C value from −27.09‰ in summer to −25.47‰ in winter). The increased δ13C value in winter (heating period) is most probably caused by uncontrolled contribution of coal soot. On the basis of isotopic mass balance the calculated contribution of anthropogenic organic particles in the atmosphere reached in winter season 72% in Czerniawa and 79% in Cieplice.

Sn4+-containing LDH was prepared using the co-precipitation method at constant pH, and characterized using X-ray diffraction, UV–vis diffuse reflectance spectroscopy and TG/DTG methods. The obtained product was further exposed to different thermal treatments in order to obtain nano-sized coupled ZnO/SnO2 systems with enhanced photocatalytic performances than the ones obtained by mixing the two semiconductor oxides. The formation of a well-defined ZnO/SnO2 system and the crystallite size, fully investigated using XRD, micro-Raman scattering and UV–vis DR techniques, were found to be influenced by the nature of the precursors and the calcination temperature. The photocatalytic activity of the ZnO/SnO2 systems, evaluated for the photodegradation of methyl orange (MO) dye, was studied as a function of the initial pH, catalyst loading and the calcination temperature. The metal dispersion supplied by layered structures proved to be an advantage when preparing coupled ZnO/SnO2 systems, the photocatalytic activity being ∼2.3 times higher comparing with the physical mixtures performances. The maximum photocatalytic activity of the coupled ZnO/SnO2 system having a layered precursor was observed when using neutral pH, at a catalyst loading of 1 g/L calcined at 600 °C for 4 h.

A comprehensive analysis of individual welding fume particles of different size fraction has been performed by applying of an innovative combination of the energy-dispersive x-ray fluorescence spectroscopy (EDXRF), micro-Raman spectroscopy (MRS) and electron probe microanalysis (EPMA). Owing to this set of analytical techniques, a systematic study of the chemical composition along with the size, morphology and structure parameters of the collected welding particles was performed. The results show distinct interdependencies between the particles' elemental composition and their sizes and structures, which are consistent with commonly assumed mechanisms of their formation and evolution. In particular, interactions between the particles of fine and coarse fractions as well as regularities in distribution of the most toxic welding fume components (Mn and its oxides) have been observed. Copyright © 2007 John Wiley & Sons, Ltd.

The “fingerprinting” of a molecular structure obtained by micro-Raman spectroscopy (MRS) can be successfully complemented by means of X-ray spot analysis through the application of scanning electron microscopy equipped with an X-ray detector (SEM/EDX). The elemental composition revealed by SEM/EDX is essential for a correct interpretation of the collected Raman spectra. The results presented here illustrate how the two techniques can be combined to characterize geological samples, especially in the case of individual particles. The samples involved in the experiments were Zr- and Ti-bearing sand from South Africa (with major minerals such as zircon and rutile) and U mine tailings from Hungary (rich with feldspars, quartz and sulphate minerals). Mineral phases detected by MRS were identified according to their respective main Raman shifts, with a spatial resolution up to 1 μm, depending on the parameters set. Some unusual and sometimes inexplicable Raman activity was observed, which was ascribed to and rationalized by the presence of accompanying elements as detected with EDX. The relocation of a particle by means of the two instruments was facilitated with TEM grids. Although the limitations of the sequential use of SEM/EDX and MRS, such as different beam sizes, probing depth and surface topography, should be considered in their application to the analysis of individual geological particles, the two methods appeared to be complementary. Not only do they provide correlated chemical information about the sample, but also enable chemical characterization that would be otherwise incomplete when analyzed on a stand-alone basis.

In this paper the porosity and adsorption properties of dolomitic sorbents, prepared via thermal decomposition of dolomite, are presented. Thermal decomposition of carbonates, as a result of heating, is governed by a number of factors, e.g. temperature, heating time, atmosphere over a heated sample and sample weight and each of these has its role in the creation of new solid phase. It has been experimentally stated that the heating of dolomite at 800 °C leads to the partial decomposition (magnesium carbonate dissociation) and the creation of a new solid—a mixture of calcite and magnesium oxide. The increase of heating time and a sample weight result in the decrease of new sorbents porosity. Of the sorbents prepared in various atmospheres, the most developed porous structure is achieved by the sample heated in the inert one. Adsorption properties of new sorbents have been estimated by means of gas chromatography (GC) method. Some information about the energetic heterogeneity of the examined sorbents may be obtained from the adsorption energy distribution function χ(e).

Adsorption properties with respect to certain toxic substances as well as porosity investigations of raw and thermally modified dolomite are presented. After the partial decomposition of dolomite at 800°C a new so-called ‘dolomitic’ adsorbent of the calcium carbonate skeleton and pumice structure was obtained. Its physicochemical properties are significantly different from those of the raw material, e.g. the specific surface area increases 37 times and the adsorption capacity for SO2 increases approximately 15 times, which makes the new adsorbent useful in the protection of the environment.

In this paper the results of the qualitative analysis of the basic elements and impurities of the domestic feldspar are presented. From n-octane and toluene adsorption measurements the components of the free surface energy were calculated and from the porosity investigations the pore size distribution curves were obtained. The adsorption and mercury porosimetry data showed the energetical and structural heterogeneity of the examined material. Having in consideration the industrial application of this mineral, preliminary tests of the chemical purification from iron additives by some acids were carried out. It appeared that the best results were achieved after etching it with aqua regia (nitrochloric acid).

Several specimens of Libyan desert glass (LDG), an enigmatic natural glass from Egypt, were subjected to investigation by micro-Raman spectroscopy. The spectra of inclusions inside the LDG samples were successfully measured through the layers of glass and the mineral species were identified on this basis. The presence of cristobalite as typical for high-temperature melt products was confirmed, together with co-existing quartz. TiO2 was determined in two polymorphic species rutile and anatase. Micro-Raman spectroscopy proved also the presence of minerals unusual for high-temperature glasses such as anhydrite and aragonite.

Samples of dolomite were heated up to the temperature at which the decomposition of MgCO 3 took place, and then some surface properties were investigated. Adsorption isotherms of n-octane and toluene were determined as well as the pore size distribution and the specific surface area. The decomposition of MgCO 3 resulted in an increase of the specific surface area and in certain changes of dolomite porosity. From the adsorption measurements the film pressure for both adsorbates was determined, and then the dispersion and the polar components of the surface free energy of dolomite were calculated and discussed. Based on the derivative of the film pressure with respect to the amount adsorbed the surface heterogeneity was estimated. It appears that two kinds of active sites for n-octane adsorption, and one kind for toluene adsorption, may be expected on the surface of dolomite.

Physicochemical investigations of thermal decomposition and adsorption properties of dolomite samples originating from the Oldrzychowice-Romanowo deposit (Poland) were made using differential thermal analysis and gas chromatography. The derivatographic measurements showed a two-step thermal decomposition of the tested mineral. The adsorption isotherms of n-octane, toluene, and water were determined using GC. The components of the free surface energy were calculated from the Bangham-Razouk equation. The amounts of selected metals contained in dolomite samples were measured by absorption atomic spectroscopy. From the results obtained, the adsorption properties of the investigated mineral were determined.

Composition of the prehistoric pigments (from Carriqueo rock shelter, Rio Negro province, Argentina) has been analysed by means of molecular spectroscopy (Fourier transform infrared (FTIR) and micro-Raman) and scanning electron microscopy (SEM) coupled to an energy-dispersive X-ray spectrometer (EDS). Red and yellow pigments were recognized as red and yellow ochre. The matrix of the pigments is composed of one or more substances. According to the matrix composition yellow and red pigments were also divided into two groupsi.e. those containing kaolinite or sulphates. Green pigment was detected as green earth, made up of celadonite as a chromophore.

Samples of the secondary uranium minerals collected in the abandoned uranium mine at Pecs (Hungary) were investigated by two micro-techniques: scanning electron microscopy (SEM/EDX) and micro-Raman spectroscopy (MRS). They were applied to locate U-rich particles and identify the chemical form and oxidation state of the uranium compounds. The most abundant mineral was a K and/or Na uranyl sulphate (zippeite group). U(VI) was also present in the form showing intensive Raman scattering at 860 cm−1 which can be attributed to uranium trioxide. This research has shown the successful application of micro-Raman spectroscopy for the identification of uranyl mineral species on the level of individual particles.

Soil samples from an abandoned uranium mine have been investigated in order to determine the molecular phases of uranium compounds. The experiments were carried out with soil particulate matter, collected randomly from the area of the formerly exploited ore. To select the particles rich with uranium, scanning electron microscopy with energy-dispersive X-ray attachment (SEM/EDX) was applied first. Afterwards, the particles were relocated and measured by μ-Raman spectrometry (MRS). Residues of the main deposit, uraninite UO 2 , were detected, along with its alteration products. In terms of Raman scattering properties, uranium oxides are quite sensitive to the laser beam wavelength, which results in very specific features of their Raman spectra. In this paper the Raman spectra of uranium oxides of different origin and oxidation states, measured with 514 and 785 nm lasers, are also presented.

As a part of the LBA/CLAIRE-98 project (LBA, Large-Scale Biosphere–Atmosphere Experiment in Amazonia; CLAIRE, Cooperative LBA Regional Experiment), an extensive aerosol characterisation study was performed. The field work for the study took place in the Amazon Basin from 23 March to 15 April 1998. The collected aerosol samples were analysed by conventional and thin-window electron probe X-ray microanalysis (EPMA) combined with principal component analysis (PCA). Intensive transport of soil dust particles from the Sahara was observed at the end of March and beginning of April. The absolute number concentration of fine soil dust particles (0.30 μm

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, O-3 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.

The physicochemical properties of ' dolomitic' sorbents formed through the partial decomposition of dolomite have been discussed in two papers published previously dealing with the influence of temperature and the time of heating. When carried out at 800o C, the newly formed solid consisted of sponge- like calcite and finely powdered magnesium oxide which was resistant mechanically and exhibited considerably greater porosity than the raw material. Long-term heating led to a decrease in the porosity and to the partial elimination of pores. The corresponding ' dolomitic' sorbents prepared in an inert atmosphere showed even greater porosity and a different internal structure when compared to those formed in the presence of carbon dioxide. However, no changes were observed as far as the chemical composition was concerned.

The sorption capability of raw and thermally treated dolomite samples with respect to toxic ions was estimated through the adsorption of chromium(VI) from aqueous solutions. The adsorption isotherms were shown to fit the well-known Freundlich equation. The results confirm the weak adsorption of chromium(VI) on raw dolomite relative to the other dolomite-derived sorbents. The influence of ionic strength on the adsorption was also determined.

The adsorption of chromium(VI) from dilute aqueous solutions on to activated carbons at natural pH values was investigated. The activated carbons were modified to obtain materials with a well-defined surface containing inorganic impurities at ppb or ppm level. Measurements of the adsorption kinetics relative to the degree of granulation were undertaken. It was found that the reaction rate of the ions on the surface of the activated carbon rather than diffusion was the major process influencing the equilibrium. Surface reduction of CrVI to CrIII appeared to be the principal mechanism for the adsorption of chromium on the activated carbons studied. It was demonstrated experimentally that the presence of oxidizing agents dramatically changed the adsorption capacity of CrVI on the studied carbons. The influence of the ionic strength (controlled by the addition of NaCl) on the adsorption capacity was also studied. Variable and complex influences of the ionic strength on the adsorption capacity were observed.

The adsorption properties of Polish feldspar towards hydrocarbons from the gaseous phase have been studied and the adsorption energy distribution functions for n-octane, benzene and toluene are presented. It appears that there are three types of adsorption sites present on the feldspar surface examined. Treatment of feldspar with aqua regia led to the elimination of low-energy interaction centres. The adsorption properties of the raw and leached feldspar with respect to Cr VI ions have also been studied. The kinetic curves for the sorption of Cr VI ions exhibited two stages which suggest two different mechanisms of sorption. The adsorption capacity depended on the pH with a maximum for pH = 4.8. The excess adsorption isotherm of Cr VI on the raw feldspar surface showed a maximum value at 20 mmol/dm3 equilibrium concentration of Cr VI ions.

The partial decomposition of dolomite performed within the temperature range 800-1000°C provides new sorbents, the so-called 'dolomitic' sorbents, composed of calcite and magnesium oxide. Their surface properties, such as their porosity and adsorption capabilities towards hydrocarbons, are discussed. The 'dolomitic' sorbents show a much higher specific surface area and pore volume when compared to the raw dolomite; moreover, their porous structure depends on the temperature of heating. The adsorption of selected hydrocarbons on the examined sorbents was also investigated and the adsorption energy distribution functions calculated from the adsorption data.

The strategies for sampling and analysis by SEM/EDX and micro-Raman spectrometry for individual airborne particles analysis as applied at the University of Antwerp (Belgium) by the MITAC group have been reviewed. Microbeam techniques provide detailed information concerning the origin, formation, transport, reactivity, transformation reactions and environmental impact of particulate matter. Moreover, some particles of certain chemical properties have been recognized as a threat for human health and cultural heritage objects. However, the small sizes of particles result in specific problems with respect to single particle analysis. Development of equipment and software for improvement of analysis and quantification are reported.