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Abstract

A continuum source atomic absorption spectrometry (CS-AAS) instrument consisting of a high-resolution echelle spectrometer and a two dimensional charge coupled device (2D-CCD) with a high frame rate was used to measure intensities as a function of height and time in the graphite furnace. The image of the furnace was reduced to a height less than that of the entrance slit to allow the full vertical profile of the furnace to be viewed. Spatially resolved absorbance, A SR , was computed as the average of the computed absorbances for each of the vertical elements, or pixels. Spatially integrated absorbance, A SI , was computed by summing the intensities for each of the vertical pixels and computing a single absorbance. A SR and A SI were computed for three viewing regions: the full image of the furnace (a 6 mm region), the image of the region above the platform (a 4 mm region) and a 2 mm region anywhere within the furnace, which corresponds to a sub-sample of the furnace image with a 2 mm slit height. Photometric errors induced by analyte non-homogeneity were greatest for platform atomization when the full furnace image was viewed and for either platform or wall atomization when a 2 mm sub-section of the furnace was viewed. These photometric errors had the potential for producing analytical errors only when a 2 mm sub-section was viewed. Analytical errors introduced by photometric errors for just four elements in a single standard reference material, Citrus Leaves, ranged from z5% to 215%. These results suggest that photometric error is problematic for conventional line source AAS.

The spatial distribution and photometric and analytical accuracy of Sn determined by graphite furnace atomic absorption spectrometry in the presence of sulfates and palladium

“…This expected gradient is the normal gradient and has been observed, with varying degrees of intensity, for all elements that interact with the carbon wall (i.e., Al, Cu, Cr, and Pb in ref. 20 and Al, Co, Mn, and Pd in ref. 17).…”

“…The experimental setup has been described previously. 20 It consists of a 300 W xenon arc lamp with an integral parabolic reflector (Cermax LX300UV, ILC Technology, Sunnyvale, CA, USA), a longitudinally heated graphite furnace (PerkinElmer Corporation, HGA 500, Norwalk, CT, USA), an autosampler (PerkinElmer, AS-72), an echelle polychromator (SpectraSpan V, Spectrametrics Inc., now out of business), a 2D-CCD camera (PixelVision, Beaverton, OR, USA) mounted on x-y-z-W-stage (three dimensions and angle of rotation), a ''SpectraVideo'' controller (PixelVision), and a 200 MHz Pentium computer. The 2D-CCD camera is an 86 6 80 pixel (height by width), back-illuminated, split-frame transfer device.…”

“…Gilmutdinov [3][4][5][6][7][8][18][19][20] and Harnly 19,20 used solid state array detectors to examine the analyte distribution in modern atomizers, with and without platforms. They observed gradients and concavities similar to those described by Holcombe.…”

Atomic spectrometry update. Advances in atomic emission, absorption and fluorescence spectrometry and related techniques

“…Harnly and co-workers 193,194 continue to publish interesting data from their work on spatially resolved ETAAS using a continuum source. It was observed that photometric errors induced by analyte non-homogeneity across the furnace were greatest for platform atomization when the full furnace image was viewed and for either platform or wall atomization when a 2 mm sub-section of the furnace was viewed.…”