Evidence for chamber-dependent radical sources: Impact on kinetic computer models for air pollution

A series of NO_x–air irradiations, with trace amounts of propane and propene present to monitor OH radical concentrations, have been carried out in a 5800-L evacuable environmental chamber to investigate radical levels and sources during such irradiations. The data obtained show conclusively that unknown radical sources are present, and that photolysis of initial nitrous acid can be, at best, only a minor source of radicals after ～30–60 min of irradiation.     

Analysis of toxic and radioactive components in sedimental type air particulates by INAA and XRF

The chemical composition of brown coal fuels and several sedimental type atmospheric particulate pollutants of industrial origin (e.g. fly-ash, bottom-ash, dust particulates from foundry-halls and casting-halls) was studied in relation to their toxic and their natural radioactive contents. In addition, some agricultural crops (e.g. soya bean, sunflower, rape, barley and luceme) sampled, in the near vicinity within a radius of about 10 km of the industrial centre were also analysed for significant distributions of any toxic components. Because of the high uranium and thorium concentrations in Hungarian coal fuels and, consequently, in various fly-ash particulate pollutants, the natural gamma activities of the samples were also measured and the relevant equilibriu states of the²³²Th and²³⁸U natural decay series were studied.     

Determination of thorium and uranium in air filters by XRF analysis using excitation of K-lines by radionuclides

Summary For control measurements of Th and U aerosol samples are collected on membrane or spun glass filters. The determination of the actinides is performed by XRF analysis using K-line excitation by the radionuclide ⁵⁷Co. The detection limit is about 20 g for 1 h and about 50 g for 15 min measuring time.

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Bestimmung von Thorium und Uran in Luftfiltern durch Röntgenfluorescenz-Analyse mit Hilfe der Anregung von K-Linien durch Radionuklide

     

Study of air pollution particulates by X-ray photoelectron spectroscopy

Summary This paper discusses the application of X-ray photoelectron spectroscopy to the determination of the chemical composition of sulfur and nitrogen species in air pollution particulates. Core electron chemical shift measurements are augmented by the determination of relative concentrations and volatility of particulate species.

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Untersuchung von Verunreinigungsteilchen in der Luft durch Röntgenphotoelektronen-Spektroskopie

Zusammenfassung Die Anwendung der Röntgenphotoelektronen-Spektroskopie auf die Bestimmung der chemischen Zusammensetzung von Schwefel und Stickstoff enthaltenden Verunreinigungsteilchen in Luft wird diskutiert. Messungen der chemischen Verschiebung werden ergänzt durch die Bestimmung der relativen Konzentrationen und der Flüchtigkeit der Verbindungen.

Presented at the 6th Annual Symposium on Recent Advances in the Analytical Chemistry of Pollutants, April 21–23, 1976; Vienna, Austria.     

Elemental bioaccumulators in air pollution studies

k₀-Based instrumental neutron activation analysis (k₀ INAA) was used to determine the concentrations of Cr, Fe, Co, Zn, Se, Sb and Hg in the vascular plantsCistus salvifolius andInula viscosa and in the lichenParmelia sulcata. The samples were collected in the neighbourhood of industrial complexes. The elemental accumulation in the vascular plants and the lichen are compared to optimize the choice of the bioaccumulator. It is concluded thatP. sulcata seems to be the best accumulator of the three species for the elements studied;Cistus salvifolius is sensitive to the contents of Zn, Fe, Cr and Sb in the air;Inula viscosa seems to accumulate Fe, Sb, Co, Cr and Zn. Nevertheless, it is concluded that lichen is a good air pollution indicator, while the vascular plants are not due to the large seasonal variations found in the elemental concentrations.     

Fluorescence analysis in air pollution research

Luminescence phenomena are of value in the analysis of air pollutants. The problems arising in the use of excitation and emission spectra under various conditions are discussed. Phenomena such as solvent, pH, and photochemical effects are shown to play an important role in the fluorimetric analysis of air pollutants. Many of the fluorimetric methods used in the trace analysis of organic airborne particulates involve factors such as direct measurement of the separated pollutant on a chromatogram or pherogram, quenching phenomena, scanning, excimer formation, charge-transfer fluorescence, sensitized fluorescence, and photo-oxidation on adsorbent or in solution. In addition, fluorescence assay methods are discussed in terms of selectivity, sensitivity, speed, simplicity, accuracy, precision, interferences, and the relation between concentration and fluorescence intensity.     

Aerosol and air pollution study by neutron activation analysis

Thermal neutron activation analysis technique was used in air pollution and aerosol elemental content and size distribution investigations. Air pollution samples were collected on Whatman 41 paper filters which were activated along with known quantities of standards in a flux of ～10¹³ n·cm^?2·s^?1. The activity of the samples was measured with a 40 cm³ Ge(Li) detector and analyzed with the computer program JANE, which identified the isotopes and found their quantities by normalization with the standard measurement results. Correlation between the various elements, in particular those belonging to dust from the desert and those considered typical urban air pollution, is investigated.     

Characterization of urban air pollution by total reflection X-ray fluorescence

Besides photochemical smog, particulate air pollution is a constantly growing problem in urban areas. The particulate matter present in pollution events contains often toxic or health impacting elements and is responsible for low visibility, might be triggering respiratory diseases like asthma, and can play an important role in formation or duration of smog events. To characterize particulate pollution in two different cities, samples were taken during intensive field campaigns in Chicago, IL, in 2002 and Phoenix, AZ, in 2001. Both cities experience regularly photochemical smog events as well as particulate pollution, but show very different meteorological and topographical conditions. Therefore it is expected that the particulate composition varies significantly, providing information about different pollution forms. Sampling took place in both cases at elevated locations and had a temporal resolution of 1.5 h and 1 h, respectively. The samples were analyzed by total reflection X-ray fluorescence after digestion of the filter matrix. As expected the elemental composition of particulate matter varied between both cities substantially with Phoenix showing a higher abundance of crustal elements, and Chicago enrichment in anthropogenically produced ones. In both cities diurnal patterns were found, exerting maxima in the morning and minima in the early afternoon. The diurnal pattern was much more regularly and also more strongly pronounced in Phoenix. Phoenix's valley location permits for a more stable nocturnal boundary layer to build up during the night thus trapping particulates efficiently during this time, until mixing occurs in the early morning hours and the residual layer lifts. In Chicago, the diurnal variation was less extreme, but another pattern determines the situation with the lake breeze. The lake breeze corresponds to a shift in wind direction towards the east, i.e. from Lake Michigan during the late morning. It was found that certain elemental species were enriched during a lake breeze event whereas this was not the case during other days. In conclusion, the low sample mass needed for TXRF analysis and the corresponding short sampling times, permitted the observation and characterization of local meteorological patterns in Phoenix and in Chicago.     

Investigation of air pollution in Chile using biomonitors

A project has been undertaken to carry out a long term study on atmospheric air pollution in Chile using biomonitors. Samples of different species of lichens were collected in clean areas (native forest), analyzed and transplanted to the Santiago Metropolitan Area. In addition, samples of Tillandsia recurvata were collected in the Metropolitan Area for comparison purposes. The preparation of the samples was done under controlled, cryogenic conditions and analyzed by neutron activation analysis and solid sampling atomic absorption spectrometry. As part of the routine QA/QC procedures, the analytical laboratories, have participated in intercomparison runs organized by the IAEA for the determination of trace and minor elements in two lichens samples. The present paper describes the activities carried out within the framework of this project. This revised version was published online in July 2006 with corrections to the Cover Date.     

Study on air pollution monitoring in Korea using low volume air sampler by instrumental neutron activation analysis

The aim of this research was to enhance the use of nuclear analytical techniques for air pollution studies and to study the feasibility of the use of instrumental neutron activation analysis (INAA) as a routine monitoring tool to reveal environmental pollution sources. For the collection of air particulate samples, the Gent stacked filter unit, low volume sampler with Nucleopore membrane filters were used. Trace elements in samples collected at two suburban residential sites, Taejon and Wonju city in the Republic of Korea, were analyzed by INAA. Variations of the elemental concentrations were measured monthly and the enrichment factors were calculated for the fine (<2 μm EAD) and coarse size (2–10 μm EAD) fractions. The analytical data were treated statistically to estimate the relationship between the two variables, the concentrations of elements and the total suspended particulate matter. The results were used to describe the emission source and their correlation.     

Elemental analysis of alloys by XRF

XRF was used for routine analysis of different kinds of alloys, such as archeological findings, materials used in dentistry, and Al alloyed with Ga used in industry. The results of these analyses are described in this paper.     

An indirect study of air pollution by neutron activation analysis of snow

Al, As, Br, Cd, Ce, Cl, Co, Cs, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Sb, Sc, Sr, Ti, V and Zn were determined in the soluble and insoluble fractions of snow which was collected at 6 differents sites in the Montreal area. From these data the variability coefficients and the enrichment factors were calculated and the probable sources of each element are discussed. The overall concentrations found in the snow were compared with the concentrations of these elements in the air sampled in the same area by high volume samplers. From these, the snow-out ratios for Cr, Cu, Fe, Mn, V and Zn and their mean were calculated. They are equal to 3338, 3389, 2322, 526, 563, 2603 and 2913 m³/kg respectively.     

X-射线荧光光谱法(XRF)测定钼精矿中多种元素

详细论述了压片法及熔融片法测定钼精矿的分析条件。其中压片法通过大量采用同一矿区的生产样品经化学定值后作为校准样品建立校准曲线,因此粒度效应和矿物效应基本上可忽略。详细地讨论了元素之间谱线干扰、背景和脉冲高度选择。使用经验系数法校正基体效应,可准确测定钼精矿中的钼、硫、铁、铜、铅、锌等11种元素。在熔融片法中主要讨论了元素谱线的选择及其相互之间的干扰,经理论α系数校正后,可准确测定不同钼矿中的多种元素,其适用范围更广。     

Determination of selenium in blood serum by XRF

Direct determination of selenium in biological tissues by X-ray emission spectroscopy is not possible due to the limited sensitivity of all modes of sample excitation. Therefore, it is necessary to develop a preconcentration procedure to bring selenium to detectable level. In this paper a rapid and simple chemical preparation procedure including coprecipitation with APDC for the analysis of selenium in blood serum by X-ray emission spectroscopy is described.     

X荧光光谱法测定催化剂中的镍和钼

本文研究了用化学试剂人工合成标样，熔融法制样，散射背景校正基体效应，X射线荧光光谱法同时测定加氢催化剂中镍和钼的方法，并获得了较好的效果。