Determination of elemental composition of atmospheric aerosol in the urban area of Islamabad, Pakistan

Summary This study provides useful information about the level and chemical composition of particulate matter and about the possible sources of the aerosol pollutant in Islamabad, the capital of Pakistan. Atmospheric aerosol samples were collected during winter (January and February) 1995, from two locations of Islamabad, namely of Sector F-7 and Sector I-9. Twenty-four elements were detected by using thermal neutron activation analysis (NAA) and atomic absorption spectrometry (AAS). The concentration of total suspended particulates (TSP) in the area around the industrial sector (I-9) was found to be more than twice higher (297 μg/m³) than in the Sector F-7 (133 μg/m³). The enrichment factor analysis revealed Zn, As, Br, Sb, I and Pb, originated mainly from anthropogenic sources. The elemental ratio analysis indicated that both Sectors I-9 and F-7 are under the influence of coal burning processes whereas transportation is responsible for the toxic pollutants Pb and Br. The present results were discussed and compared with those of the literature. The results may also serve as base line level as this work employed samples collected in 1995 and many of the air environmental change factors occurred after the sampling year.     

Trace elemental composition of Nigerian coal measured by neutron activation analysis

The instrumental neutron activation analysis (INAA) technique has been used to determine 17 major, minor, and trace elements in samples of the three major sources of Nigerian coal. The NBS Standard Reference Material, Coal SRM 1632, was also analyzed, for the purpose of verifying the accuracy of the method. The results obtained with it were in good agreement with the NBS certified values. The concentrations of the major elements determined for the Nigerian coal were found to be much lower than the mean values of those reported for coal samples from other parts of the world.     

Analytical and statistical analysis of elemental composition of lichens

The elemental composition of lichens from remote southern South America regions has been studied with analytical and statistical techniques to determine if the values obtained reflect species, growth forms or habitat characteristics. The enrichment factors are calculated discriminated by species and collection site and compared with data available in the literature. The elemental concentrations are standardized and compared for different species. The information was statistically processed, a cluster analysis was performed using the three first principal axes of the PCA; the three groups formed are presented. Their relationship with the species, collection sites and the lichen growth forms are interpreted.     

Cluster analysis of the elemental composition of five austrian peats

The elemental composition of peat depends on the plant residues from which the peat was formed. The concentrations of 45 elements were determined for five peat samples by plasma emission spectrometry. Literature data on the composition of three bogs was added. The elemental abundances of six rock or soil categories, the elemental compositions of several peat-forming plants, and the results of the elemental analyses of bog samples, were examined by the SIMCA method. A clear difference was found between fens and raised bogs. Factor analysis of the elemental compositions shows that the concentrations of most of the elements reflect their natural abundance in the surrounding region. Some concentrations are influenced by anthropogenic pollution, e.g. lead, and by plant metabolism. The cluster analysis together with the training sets shows the degree of the deposition of mineral material from adjacent rivers and the type of plant growth which formed the peat.     

Determination of the elemental composition of copper and bronze objects by neutron activation analysis

A method for the elemental analysis of copper and bronze objects is described. Na, Co, Ni, Cu, Zn, As, Ag, Sn, Sb, W, Ir and Au are determined through instrumental neutron activation analysis. Mg, Al, V, Ti and Mn are determined after chemical separation using anionic exhange. The detection limits for a number of other elements are also given. Results for NBS standard reference materials are presented and the results compared with the recommended values. The agreement is good. The results of the analysis of five ancient bronze and two copper objects are presented.     

Chemical composition and reaction analysis of single aerosol particles

In situ measurements of gas-liquid surface reactions of single aerosol microdroplets are presented. By means of optical levitation in combination with elastic (Mie) and inelastic (Raman) light scattering it is possible to get information on the chemistry of e.g. acid/base reactions as well as the physical behavior of single microparticles.     

Chemical composition and reaction analysis of single aerosol particles

In situ measurements of gas-liquid surface reactions of single aerosol microdroplets are presented. By means of optical levitation in combination with elastic (Mie) and inelastic (Raman) light scattering it is possible to get information on the chemistry of e.g. acid/base reactions as well as the physical behavior of single microparticles.     

Determination of elemental composition of aluminosilicate clays by EDXRF

Aluminosilicate clay samples were analyzed for the constituent elements with respect to a certified reference material using microcrystalline cellulose powder as a binder for presentation as a pressed pellet to an energy dispersive X-ray fluorescence spectrometer. Sample preparation for presentation is highlighted. The data manipulation to achieve the analytical accuracy from the inherent precision is discussed.     

Status report: preparing an ambient aerosol filter reference material for elemental analysis

Summary For the elemental analysis of aerosol filter samples by X-ray techniques there is a lack of adequate reference materials (RM). No genuine aerosol matrix is available, which has been collected on membrane filters from ambient aerosol and can be distributed in the same physical form. It is possible to collect high-volume ambient aerosol samples, with a uniformity of 5% to 15%, in the elemental deposit ranges of 10 ng/cm² to g/cm² within probed spots of only 4 mm diameter on suitable filter materials. An aerosol sampling campaign is being organized, aiming at the collection of large enough filter batches of aerosols of different origin, suitable for characterization by different analytical methods and compatible with X-ray fluorescence analysis (XRF). To a large extent, the production control - especially for the homogeneity of the elemental mass deposits - will be performed by particle-induced X-ray emission (PIXE) analysis on residual material without consuming any part of the candidate RM stock.Working under contract CBNM/ST/91-147     

The use of Si carriers for aerosol particle collection and subsequent elemental analysis by total-reflection X-ray fluorescence spectrometry

The adoption of polished Si carriers was studied for the sensitive elemental analysis of aerosol particles using total-reflection X-ray fluorescence (TXRF) spectrometry. The surface roughness of the Si carrier measured by atomic force microscopy was found to be smaller than those of glassy carbon and quartz glass carriers, which are commonly used for TXRF analysis. The detection limits of elements for the Si carrier were superior to those for the glassy carbon and the quartz glass carriers, presumably due to its smaller surface roughness. For example, the detection limit of Sr for the Si carrier was 9 pg, which was 100 times and 3 times lower than those for the glassy carbon and the quartz glass carriers, respectively. The Si carriers could be successfully applied to the direct aerosol particle collection by impaction and the subsequent elemental analysis by TXRF. From the results of the elemental analysis of aerosol particles, the variations in the concentrations of K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn Sr and Pb with time could be clarified.     

Isotopic composition of commercially available uranium chemicals and elemental analysis standards

Journal of Radioanalytical and Nuclear Chemistry - Reference information on isotopic composition of various uranium materials, determined with high accuracy and precision, is of essential value for...     

Size spectra for trace elements in urban aerosol particles by instrumental neutron activation analysis

Size-fractionated aerosol samples collected with micro-orifice impactors at Camden, NJ, a heavily industrialized urban area, and at two sites near Washington, DC, were analyzed for elemental constituents determined instrumentally from short-lived neutron activation products. A least-squares peak-fitting method was used with impactor calibration data to determine log-normal distribution parameters, i.e., mass median aerodynamic diameter (MMAD) and geometric standard deviation (_g) for particles bearing S, V, Br, and I. For these elements, MMADs ranged from 0.24 to 0.65 m; 0.23 to 0.53 m; 0.22 to 0.61 m, and 0.20 to 0.48 m, respectively.     

Absolute analysis by atomic absorption

The paper describes an attempt to place atomic absorption spectroscopy on an absolute basis. Both the theoretical and experimental aspects of the problem are considered.

The study is based upon the construction of a precision burner which provides a homogeneous working zone of definite size into which the atoms to be studied are introduced. Experimental results obtained by means of this burner are used as a guide in formulating a mathematical model of the absorption process.

It is suggested that a model based upon the Voigt equation will suffice to explain the qualitative and quantitative results from an atomic absorption experiment. The extent to which inorganic compounds are dissociated in a flame, the degree of pressure broadening of an absorption line and the characteristics of the emission line from the source constitute the major unknown factors in the application of the theory.     

A study of the elemental composition of diabases by instrumental neutron activation and X-ray fluorescence analysis

The distribution of the elemental composition was studied mainly for microelements in the diabases of the Pechenga suite subjected to various changes. Investigations were conducted by a combination of instrumental neutron activation INAA and X-ray fluoresence XRFA analyses. The INAA was conducted with sample weights of 20–100 mg exposed to irradiation in a nuclear reactor by a flux of neutrons ≈10¹³ n·cm⁻²·s⁻¹. Measurements were carried out by means of a semi-conductor gamma-spectrometer with a Ge(Li) detector. The determination of Al, Mn, Mg, Ti, V, Ca was conducted by short-lived isotopes, while the determination of Na, Sc, Fe, Co, Cr, Hf, Th, La, Ce, Sm, Eu, Yb, Lu by longlived ones. For XRFA samples weighing up to 2 g were irradiated by means of an¹⁰⁹Cd isotope source and were measured by a spectrometer with a Si(Li) detector and beryllium window. By this method we determined the Sr, Zr an Nb contents. Continuous distribution histograms were plotted for the concentration of 22 elements and some of their ratios. Considerable variations in microelemental composition observed in a number of cases make it possible to assess the character of past processes of diabasic change.     

Comparison of elemental composition of hair between osteoporotic and normal women by instrumental neutron activation analysis

Instrumental neutron activation analysis (INAA) was carried out on hair samples from a group of twenty patients undergoing a study of osteoporosis. Half of these were judged normal. Fourteen elements were measured but only calcium was found to have a correlation with the disease state. Calcium levels in hair were significantly lower (99% confidence level) in patients with osteoporosis. Conversely, calcium levels in the blood of osteoporotic patients were significantly higher (95% confidence level) than those in normals. Though the group studied was small it is felt that the levels of calcium in hair may be of value in diagnosing osteoporosis.     

Determination of the chemical composition of the South Pole aerosol by instrumental neutron activation analysis

Atmospheric particulate samples were collected at the geographic South pole, using cellulose and polycarbonate filters and cascade impactors. The samples were analysed for 40 elements by instrumental neutron activation analysis. From the filter samples atmospheric concentrations for 33 elements could be obtained. The highest atmospheric concentrations were found for S: 49 ng/standard cubic meter (SCM) of air, Na: 3.3 ng/SCM and Cl: 2.6 ng/SCM. In the cascade impactor samples, only a few elements were observed above blank. For these elements it could be concluded that they are associated for over 80–90% with submicron size paricles.     

Identification of provenance of obsidian samples analyzing elemental composition by INAA

The results of a study on 111 obsidian artifacts collected during an archaeological campaign performed by the University of Siena near Sesto Fiorentino (Florence, Italy) are reported. Earlier, we used the concentration ratios among some elements as reported in the literature to discriminate the deposit sources. Later, optimizing the characterization and for having a more strong classification, multivariate chemiometric investigation has been performed (multivariate statistical analysis in Principal Components and Discriminating Factor Analysis). The data obtained show three wellseparated groups connected to the relative sites in Lipari and in Sardinia (flows A and C from Arci Mountain).     

Direct infusion analysis of nucleotide mixtures of very similar or identical elemental composition

The challenges posed by the analysis of mono‐nucleotide mixtures by direct infusion electrospray ionization were examined in the context of recent advances of mass spectrometry (MS) technologies. In particular, we evaluated the merits of high‐resolution mass analysis, multistep gas‐phase dissociation, and ion mobility determinations for the characterization of species with very similar or identical elemental composition. The high resolving power afforded by a linear trap quadrupole‐orbitrap allowed the complete differentiation of overlapping isotopic distributions produced by nucleotides that differed by a single mass unit. Resolving ¹²C signals from nearly overlapped ¹³C contributions provided the exact masses necessary to calculate matching elemental compositions for unambiguous formulae assignment. However, it was the ability to perform sequential steps of gas‐phase dissociation (i.e. MSⁿ‐type analysis) that proved more valuable for discriminating between truly isobaric nucleotides, such as the AMP/dGMP and UMP/ΨMP couples, which were differentiated in the mixture from their unique fragmentation patterns. The identification of diagnostic fragments enabled the deconvolution of dissociation spectra containing the products of coexisting isobars that could not be individually isolated in the mass‐selection step. Approaches based on ion mobility spectrometry‐MS provided another dimension upon which isobaric nucleotides could be differentiated according to their distinctive mobility behaviors. Subtle structural variations, such as the different positions of an oxygen atom in AMP/dGMP or the glycosidic bond in UMP/ΨMP, produced detectable differences in the respective ion mobility profiles, which enabled the differentiation of the isobaric couples in the mixture. Parallel activation of all ions emerging from the ion mobility element provided an additional dimension for differentiating these analytes on the basis of both mobility and fragmentation properties. Copyright © 2013 John Wiley & Sons, Ltd.     

Examination of clean room aerosol particle composition by total reflection X-ray analysis and electron probe microanalysis

Aerosol particles with a minimum diameter of 0.1 μm were sampled with an impactor at various places in three class 1000 clean-room complexes. The elemental composition of the integral samples was determined by total reflection X-ray fluorescence (TXRF) analysis. With this new application and a combination of tried and tested sampling and analysing methods it was possible to detect elements in the pg m⁻³ range in clean rooms. The elemental composition of single particles was analysed by electron probe microanalysis (EPMA). Furthermore, EPMA elemental maps can yield further valuable information on the homogeneous structure of particles and quantitative particle analysis can lead to respective compound identification.     

Frontiers in elemental analysis by mass spectrometry

New developments in inductively coupled plasma mass spectrometry (ICP-MS) and laser desorption-time-of-flight mass spectrometry (LD-TOF-MS) for inorganic analysis are described. These include fundamental studies of the ion extraction, process in ICP-MS, development of a highly efficient nebulizer, isotope tracer studies, measurement of elemental speciation by liquid chromatography with ICP-MS detection and characterization of the structures of solids by ion association. The possibilities of determining inorganic species in solutions by electrospray MS are also described.