Filters atomic absorption

Standardized techniques atomic absorption (AAA) and photometric (FMA) of the analysis and designed by us a technique X-Ray fluorescence of the analysis (XRF) for metals definition in air of cities and the working areas of plants to production of non-ferrous metals are applied. The samples of aerosols were collected on cellulose (AFA-HA) and perchlorovinyl (AFA-VP and FPP) filters (Russia). The techniques AAA and FMA include a stage of an acid-temperature ashing of a loaded filter or selective extraction of defined elements from filter by approaching dissolvent. At XRF loaded filters were specimens. 

Particulate lead in aerosol Collected on filter with atomic absorption spectrometry... 

With flame emission spectroscopy, there is greater likelihood of spectral interferences when the line emission of the element to be determined and those due to interfering substances are of similar wavelength, than with atomic absorption spectroscopy. Obviously some of such interferences may be eliminated by improved resolution of the instrument, e.g. by use of a prism rather than a filter, but in certain cases it may be necessary to select other, non-interfering, lines for the determination. In some cases it may even be necessary to separate the element to be determined from interfering elements by a separation process such as ion exchange or solvent extraction (see Chapters 6, 7). 

D. Wienke, T. Vijn and L. Buydens, Quality self-monitoring of intelligent analyzers and sensor based on an extended Kalman filter an application to graphite furnace atomic absorption spectroscopy. Anal. Chem., 66 (1994) 841-849. 

Dendrimer encapsulated Pt nanoparticles (DENs) were prepared via literature methods (1, 11). PtCl42 and dendrimer solutions (20 1 Pt2+ dendrimer molar ratio) were mixed and stirred under N2 at room temperature for 3 days. After reduction with 30 equivalents of BH4 overnight, dialysis of the resulted light brown solution (2 days) yielded Pt2o nanoparticle stock solution. The stock solution was filtered through a fine frit and Pt concentration was determined with Atomic Absorption Spectroscopy (11). Details on catalyst characterization and activity measurements have been published previously (11). 

Cranston and Murray [35,36] took samples in polyethylene bottles that had been pre-cleaned at 20 °C for four days with 1% distilled hydrochloric acid. Total chromium Cr(VI) + Cr(III) + Crp (Crp particulate chromium) was coprecipitated with iron (II) hydroxide, and reduced chromium Cr(III) + Crp was co-precipitated with iron (III) hydroxide. These co-precipitation steps were completed within minutes of the sample collection to minimise storage problems. The iron hydroxide precipitates were filtered through 0.4 pm Nu-cleopore filters and stored in polyethylene vials for later analysis in the laboratory. Particulate chromium was also obtained by filtering unaltered samples through 0.4 pm filters. In the laboratory the iron hydroxide co-precipitates were dissolved in 6 N distilled hydrochloric acid and analysed by flameless atomic absorption. The limit of detection of this method is about 0.1 to 0.2 nM. Precision is about 5%. 

Spencer and Sachs [29] determined particulate aluminium in seawater by atomic absorption spectrometry. The suspended matter was collected from seawater (at least 2 litres) on a 0.45 tm membrane filter, the filter was ashed, and the residue was heated to fumes with 2 ml concentrated hydrofluoric acid and one drop of concentrated sulfuric acid. This residue was dissolved in 2 ml 2 M hydrochloric acid and the solution was diluted to give an aluminium concentration in the range 5-50 pg/1. Atomic absorption determination was carried out with a nitrous oxide acetylene flame. The effects of calcium, iron, sodium, and sulfate alone and in combination on the aluminium absorption were studied. 

The collection behaviour of chromium species was examined as follows. Seawater (400 ml) spiked with 10-8 M Crm, CrVI, and Crm organic complexes labelled with 51Cr was adjusted to the desired pH by hydrochloric acid or sodium hydroxide. An appropriate amount of hydrated iron (III) or bismuth oxide was added the oxide precipitates were prepared separately and washed thoroughly with distilled water before use [200]. After about 24 h, the samples were filtered on 0.4 pm nucleopore filters. The separated precipitates were dissolved with hydrochloric acid, and the solutions thus obtained were used for /-activity measurements. In the examination of solvent extraction, chromium was measured by using 51Cr, while iron and bismuth were measured by electrothermal atomic absorption spectrometry. The decomposition of organic complexes and other procedures were also examined by electrothermal atomic absorption spectrometry. 

To determine down to 2.4 xmol/l of copper in seawater, Nishoika et al. [282] complexed the copper with di-ethyl-dithio carbamate, precipitated with ferric hydroxide, filtered off and dissolved the precipitate with nitric acid, and determined copper by electrothermal atomic absorption spectrometry. 

Benzwi [409] determined lithium in Dead Sea water using atomic absorption spectrometry. The sample was passed through a 0.45 pm filter and lithium was then determined by the method of standard additions. Solutions of lithium in hexanol and 2-ethylhexanol gave greatly enhanced sensitivity. 

Olafsson [427] has described a semiautomated determination of manganese in seawater using leucomalachite green. The autoanalyser had a 620 nm interference filter and 50 minute flow cells. Findings indicated initial poor precision was related to pFl, temperature, and time variations. With strict controls on sample acidity and reaction conditions, the semiautomated method had high precision, at least as good as that achieved by preconcentration and atomic absorption procedures, and provided precise, rapid, shipboard information... 

Nishioka et al. [525] coprecipitated nickel from seawater with sodium di-ethyldithiocarbamate, filtered, and redissolved the precipitate with nitric acid followed by electrothermal atomic absorption spectrophotography determination of the nickel. The detection limit was 0.5 p,g/l and the relative standard deviation was 13.2% at the 2 ig/l level. 

Orren [663] used atomic absorption spectrometry to determine these elements in seawater in both their soluble and insoluble forms. The alkali metals are determined directly, but the other elements are first concentrated by solvent extraction. The particulate matter content is derived by dissolving the membranes used to filter the sample and determine the metals in the resulting solution. For organic standards of known metal content, the efficiency of the technique was almost 100%. 

Berndt et al. [740] have shown that traces of bismuth, cadmium, copper, cobalt, indium, nickel, lead, thallium, and zinc could be separated from samples of seawater, mineral water, and drinking water by complexation with the ammonium salt of pyrrolidine- 1-dithiocarboxylic acid, followed by filtration through a filter covered with a layer of active carbon. Sample volumes could range from 100 ml to 10 litres. The elements were dissolved in nitric acid and then determined by atomic absorption or inductively coupled plasma optical emission spectrometry. 

The Association of Official Analytical Chemists is utilizing atomic absorption spectroscopy for the determination of several trace elements. McBride 274>27s), has conducted collaborative and ruggedness studies for a number of elements in fertilizers. He dissolves the sample in hydrochloric acid, filters, and dilutes to vo-... 

The basic instrumentation used for spectrometric measurements has already been described in the previous chapter (p. 277). Methods of excitation, monochromators and detectors used in atomic emission and absorption techniques are included in Table 8.1. Sources of radiation physically separated from the sample are required for atomic absorption, atomic fluorescence and X-ray fluorescence spectrometry (cf. molecular absorption spectrometry), whereas in flame photometry, arc/spark and plasma emission techniques, the sample is excited directly by thermal means. Diffraction gratings or prism monochromators are used for dispersion in all the techniques including X-ray fluorescence where a single crystal of appropriate lattice dimensions acts as a grating. Atomic fluorescence spectra are sufficiently simple to allow the use of an interference filter in many instances. Photomultiplier detectors are used in every technique except X-ray fluorescence where proportional counting or scintillation devices are employed. Photographic recording of a complete spectrum facilitates qualitative analysis by optical emission spectrometry, but is now rarely used. 

Flame emission spectrometry is used extensively for the determination of trace metals in solution and in particular the alkali and alkaline earth metals. The most notable applications are the determinations of Na, K, Ca and Mg in body fluids and other biological samples for clinical diagnosis. Simple filter instruments generally provide adequate resolution for this type of analysis. The same elements, together with B, Fe, Cu and Mn, are important constituents of soils and fertilizers and the technique is therefore also useful for the analysis of agricultural materials. Although many other trace metals can be determined in a variety of matrices, there has been a preference for the use of atomic absorption spectrometry because variations in flame temperature are much less critical and spectral interference is negligible. Detection limits for flame emission techniques are comparable to those for atomic absorption, i.e. from < 0.01 to 10 ppm (Table 8.6). Flame emission spectrometry complements atomic absorption spectrometry because it operates most effectively for elements which are easily ionized, whilst atomic absorption methods demand a minimum of ionization (Table 8.7). 

Air-dry soil is mixed with 0.02 M calcium chloride solution (1 2 ratio, for instance, 10-g soil 20 mL 0.02 M CaCl2 solution) and mixed for 1 hour. The pH of the suspension can be measured directly. In addition, the solution can be filtered for the determination of aluminum or magnesium by atomic absorption spectroscopy (AAS) or inductively coupled plasma (ICP) spectroscopy (adapted from Reference 5). 

WA water quality labs by atomic absorption and autoanalyzer techniques. Charge balance calculations Indicated that all dissolved species of significance were analyzed. Comparison of filtered and unflltered aliquots suggested that un-lonlzed species were not present In appreciable quantities. Sampling and analysis uncertainties were determined by the operation of two co-located samplers for 16 weeks. The calcium and sulfate data were corrected for the Influence of sea salt to aid In the separation of the factors. This correction was calculated from bulk sea water composition and the chloride concentration In rainwater (11). Non seasalt sulfate and calcium are termed "excess" and flagged by a ... 

Results(79) from a Round Robin analyses for the lead content of air particulate filters were given along with the average values obtained from 65 laboratories participating in the study. The procedures used by the other laboratories included x-ray, FAA, flameless atomic absorption, emission spectrometric, and dithizone-spectropho-tometric. The overall analytical agreement was very good. 

Montero et al. reported an indirect atomic absorption spectrometric method combined with a flow-injection precipitation technique for the determination of procaine in pharmaceutical preparations [53]. The precipitate formed by the injection of Co(II) into a sample stream containing 10 to 110 pM procaine at pH 8.0 to 9.1 was retained on a stainless steal filter, and analyzed at 240.7 nm by an online atomic... 

In a search for sources of alkaline materials in rural air and rain, we have sampled and performed multi-element analyses on ambient particulate matter and potential source materials. Ambient aerosols were sampled daily using single Nuclepore filters or Florida State University "streakers." Samples of soil and unpaved road materials were also collected and analyzed. The samples were analyzed by various multi-element methods, including ion-and proton-induced X-ray emission and X-ray fluorescence, as well as by atomic absorption spectrophotometry. Visual observations, as well as airborne elemental concentration distributions with wind direction and elemental abundances in aerosols and source materials, suggested that soil and road dust both contribute to airborne Ca. Factor analysis was able to identify only a "crustal" source, but a simple mass balance suggested that roads are the major source of Ca in rural central Illinois in summer. 

FAA FA FBC FC FEBEX FFFF FGD FP FSU FT FTIR FUETAP Flame atomic absorption Fly ash Fluidized bed combustion Filter cake Full-scale engineered barriers experiment (in crystalline host rock) Flow-field flow fractionation Flue gas desulphurization Fission products Former Soviet Union Fourier transforms Fourier transformed infrared spectroscopy Formed under elevated temperature and pressure... 

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