A combination of a pulsed continuum light source, a high resolution spectrometer, and a charge coupled device detector for multielement atomic absorption spectrometry

Abstract

This paper presents first results of atomic absorption measurements carried out for the development of a new multielement atomic absorption spectrometer. The results were obtained in the wavelength range 283–228 nm, using a flash lamp continuum of high intensity, a newly developed, advanced high-resolution echelle spectrometer and a charge coupled device (CCD) array as radiation detector arranged in the focal plane of the spectrometer. In this measuring method, each flash exposure yields the complete information for an absorption measurement including the background absorption. Because of the simultaneous measurement of the two intensity values I 0 and I these two quantities are processed with a correlation coefficient of r = 1. Using a graphite tube furnace as an absorber, characteristic masses of 0.6 and 18 pg are achieved for the elements Cd and Pb, respectively, which exceed those of line atomic absorption with the same absorption equipment by a factor of only 2 and 1.5, respectively. Absorption measurements were carried out on saturated Hg vapour in quartz cuvettes at room temperature. Owing to the high intensity of the continuum radiation at all wavelengths, appreciable stray light components occur in the echelle spectrometer, requiring a stray light correction of the measured intensity values.