Investigation of the feasibility to use Zeeman-effect background correction for the graphite furnace determination of phosphorus using high-resolution continuum source atomic absorption spectrometry as a diagnostic tool

The determination of phosphorus by graphite furnace atomic absorption spectrometry at the non-resonance line at 213.6 nm, and the capability of Zeeman-effect background correction (Z-BC) to deal with the fine-structured background absorption due to the PO molecule have been investigated in the presence of selected chemical modifiers. Two line source atomic absorption spectrometers, one with a longitudinally heated and the other with a transversely heated graphite tube atomizer have been used in this study, as well as two prototype high-resolution continuum source atomic absorption spectrometers, one of which had a longitudinally arranged magnet at the furnace. It has been found that Z-BC is capable correcting very well the background caused by the PO molecule, and also that of the NO molecule, which has been encountered when the Pd + Ca mixed modifier was used. Both spectra exhibited some Zeeman splitting, which, however, did not cause any artifacts or correction errors. The practical significance of this study is to confirm that accurate results can be obtained for the determination of phosphorus using Z-BC. The best sensitivity with a characteristic mass of m(0) = 11 ng P has been obtained with the pure Pd modifier, which also caused the lowest background level. The characteristic mass obtained with the mixed Pd + Ca modifier depended on the equipment used and was between m(0) = 9 ng P and m(0) = 15 ng P, and the background signal was higher. The major problem of Z-BC remains the relatively restricted linear working range

Determination of mercury in airborne particulate matter collected on glass fiber filters using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling

A study has been undertaken to assess the capability of high-resolution continuum source graphite furnace atomic absorption spectrometry for the determination of mercury in airborne particulate matter (APM) collected on glass fiber filters using direct solid sampling. The main Hg absorption line at 253.652 nm was used for all determinations. The certified reference material NIST SRM 1648 (Urban Particulate Matter) was used to check the accuracy of the method, and good agreement was obtained between published and determined values. The characteristic mass was 22 pg Hg. The limit of detection (3σ), based on ten atomizations of an unexposed filter, was 40 ng g- 1, corresponding to 0.12 ng m- 3 in the air for a typical air volume of 1440 m3 collected within 24 h. The limit of quantification was 150 ng g-1, equivalent to 0.41 ng m-3 in the air. The repeatability of measurements was better than 17% RSD (n = 5). Mercury concentrations found in filter samples loaded with APM collected in Buenos Aires, Argentina, were between < 40 ng g-1 and 381 ± 24 ng g-1. These values correspond to a mercury concentration in the air between < 0.12 ng m-3 and 1.47 ± 0.09 ng m-3. The proposed procedure was found to be simple, fast and reliable, and suitable as a screening procedure for the determination of mercury in APM samples.Fil: Araujo, Rennan G. O.. Universidade Federal de Santa Catarina; BrasilFil: Vignola, Fabíola. Universidade Federal de Santa Catarina; BrasilFil: Castilho, Ivan N. B.. Universidade Federal de Santa Catarina; BrasilFil: Borges, Daniel L. G.. Universidade Federal de Santa Catarina; Brasil. Universidade Federal da Bahia; BrasilFil: Welz, Bernhard. Universidade Federal de Santa Catarina; Brasil. Universidade Federal da Bahia; BrasilFil: Vale, Maria Goreti R.. Universidade Federal do Rio Grande do Sul; Brasil. Universidade Federal da Bahia; BrasilFil: Smichowski, Patricia Nora. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ferreira, Sérgio L. C.. Universidade Federal da Bahia; BrasilFil: Becker Ross, Helmut. Leibniz-Institut für Analytische Wissenschaften; Alemani

High-resolution continuum-source atomic absorption spectrometry: what can we expect?

A new instrumental concept has been developed for atomic absorption spectrometry (AAS), using a high-intensity xenon short-arc lamp as continuum radiation source, a high-resolution double-echelle monochromator and a CCD array detector, providing a resolution of ~2 pm per pixel. Among the major advantages of the system are: i) an improved signal-to-noise ratio because of the high intensity of the radiation source, resulting in improved photometric precision and detection limits; ii) for the same reason, there are no more 'weak' lines, i.e. secondary lines can be used without compromises; iii) new elements might be determined, for which no radiation source has been available; iv) the entire spectral environment around the analytical line becomes 'visible', giving a lot more information than current AAS instruments; v) the CCD array detector allows a truly simultaneous background correction close to the analytical line; vi) the software is capable of storing reference spectra, e.g. of a molecular absorption with rotational fine structure, and of subtracting such spectra from the spectra recorded for a sample, using a least squares algorithm; vii) although not yet realized, the system makes possible a truly simultaneous multi-element AAS measurement when an appropriate two-dimensional detector is used, as is already common practice in optical emission spectrometry; vii) preliminary experiments have indicated that the instrumental concept could result in a more rugged analytical performance in the determination of trace elements in complex matrices

Continuum Source Atomic Absorption Spectrometry: Past, Present and Future Aspects - A Critical Review

This review article covers 1½ centuries of history of continuum source atomic absorption spectrometry (CS AAS), starting with the early experiments of Kirchhoff and Bunsen in the 1860s. It also tries to explain why the technique was abandoned in the first half of the 20th century, why it was “re-discovered” in the 1960s in the USA, where several research groups worked intensively on the development of CS AAS for about four decades, and why they finally failed. This review also discusses the major advantages of modern high-resolution CS AAS (HR-CS AAS), which uses a high-resolution double monochromator and a charge coupled device array detector, which adds the wavelength as third dimension to the usual display of absorbance over time. The literature about applications of this technique has been carefully revised. Finally an attempt will be made to foresee future developments of this technique, which is obviously not an easy task.Este artigo de revisão aborda 1½ séculos de história da espectrometria de absorção atômica com fonte contínua (CS AAS), partindo dos primeiros experimentos de Kirchhoff e Bunsen nos anos 1860. Ele também tenta explicar porque a técnica foi abandonada na primeira metade do século XX, porque ela foi redescoberta nos anos 60 nos EUA, onde vários grupos de pesquisa trabalharam intensamente no desenvolvimento da CS AAS por cerca de quatro décadas e, finalmente, não obtiveram sucesso. Esta revisão também discute as principais vantagens da moderna técnica de CS AAS de alta resolução (HR-CS AAS), que usa um monocromador duplo de alta resolução e um detector com arranjo de dispositivos de carga acoplada, o qual adiciona o comprimento de onda como terceira dimensão. A literatura sobre as aplicações de HR-CS AAS foi cuidadosamente revisada. Finalmente, será feita uma tentativa de prever os avanços futuros desta técnica nova e antiga

O uso de modificadores permanentes na determinação de metais traço por GFAAS

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O uso de modificadores permanentes na determinação de metais traço por GFAAS

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