Effect of gas pressure on the collisional line width and line shift in graphite furnace atomic absorption spectrometry

Abstract

The collisional line width of the resonance atomic absorption lines of Ca, Cu and In have been measured in graphite furnace atomisers by means of a wavelength modulated echelle spectrometer and a measurement method based on transmission profile fitting. A measurement precision of k O . 1 p m is observed for Cu (324.754 nm) based on growth curve shapes measured in peak area or peak height. Time resolved line widths within a single atomisation have been measured for Ca (422.673 nm) and for In (410.176 nm), with a time resolution of 0.3 s and a precision of k0.5 pm. This measurement precision is sufficient t o show clearly the effect of increased gas pressure on the line width and the line shift. Collisional cross-sectionsfor In and Ca are estimated from the effect of pressure on the line widths and shifts and are compared with previously published values obtained using theoretical calculations.

Sub-Parts-Per-Quadrillion-Level Graphite Furnace Atomic Absorption Spectrophotometry Based on Laser Wave Mixing

“…Using graphite furnace atomization, the maximum absorption wavelength for Rb is monitored on the wavemeter at 12816.4 cm -1 (780.249 nm). Our λ max at 780.249 nm for Rb is slightly shifted from the MIT wavelength table value of 780.237 nm, and our 0.012-nm wavelength shift is within the range of common graphite furnace wavelength shift due to gas pressure …”

Continuum source atomic absorption spectrometry and detector technology: A historical perspective

“…Resonance lines for the elements Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Se, Sn, V and Zn could thus be recorded simultaneously, and the calculated absorbances were all shot noise limited. Similar systems were used by several groups for many fundamental [71][72][73][74][75][76][77][78][79][80][81][82][83][84] as well as applied [85][86][87][88][89][90][91][92][93][94][95] studies, and are also described in a number of overview papers [96][97][98][99][100]. In a detailed analysis [97], O'Haver and Messman stated that the undoubted advantages, in particular flexibility and excellent background correction, were unfortunately counterbalanced by the disadvantage that for elements with resonance lines at wavelengths shorter than 250 nm LODs were significantly poorer with CS AAS than with LS AAS.…”

Atomic absorption, atomic emission, and flame emission spectrometry

“…Other noteworthy papers on atomization include the use of a wavelength modulated echelle spectrometer to measure the effect of gas pressure on collisional line widths (153), a study of the influence of pressure on atomization (154), and the atomization of Ga (155), P (156), Hg (157), and B (158). Ohlsson and Freeh (159) determined concentrations of C, and CN under various operating conditions and compared the values with a thermodynamic equilibrium model.…”