Continuum source atomic absorption spectrometry in a graphite furnace with photodiode array detection

Abstract

A graphite furnace continuum source atomic absorption spectrometer using a photodiode array detector is described that provides high-resolution wavelength versus absorbance spectra over a 2.5-nm range for a single atomization step. The multiwavelength detection power allows the simultaneous determination of several elements, reduces problems caused by spectral interferences, and automatically corrects for nonzero background absorbance. Each spectrum is acquired in 0.33 s, and several successive spectra can be obtained during a single run. Three-dimensional wavelength-absorbance-furnace temperature spectra can be obtained by using ramped heating steps to provide a rough separation of elements in a mixture. Limits of detection calculated for 19 elements range from 0.1 pg for magnesium to 700 pg for arsenic. The sampling precision was found to be better than 10% relative standard deviation in all cases, with the precision for a single atomization being greatly increased when multiple absorption lines for a single element are observed in the spectrum. The error found for the measurement of the iron concentration in an NBS standard bronze was 8.5%, with the calculated concentration agreeing with the certified concentration within 95% confidence limits.

High-resolution continuum source electrothermal atomic absorption spectrometry — An analytical and diagnostic tool for trace analysis

“…The only other 'simultaneous' CS AAS instruments described in the literature for ET AAS used photodiode array detectors that covered a spectral range of 2.5 nm [48], 10 nm [49] and 4 nm [50], respectively, and only elements that had absorption lines falling within this narrow spectral window could be detected simultaneously. In their first work the authors investigated a 19-component mixture as well as a standard bronze and a seawater sample [48] without carrying out real determinations.…”

“…In their first work the authors investigated a 19-component mixture as well as a standard bronze and a seawater sample [48] without carrying out real determinations. In their second publication [49] the authors also concentrated mostly on detection limits without analyzing real samples.…”

Intracavity laser atomic absorption spectrometry with graphite furnace atomizer or pulsed laser sampler

“…The most spread variant of the ICLS with a broadband tunable laser is similar to that employed in conventional continuum source AAS [4], but the latter has smaller limits of detection. Therefore the ICLS commonly used the same vaporizers as the AAS: often -flame atomization [5,6], rarely -electrothermal vaporization [7,8], and in single works -electrical discharge [9,10] and laser ablation [11,12] V.S.…”

Optimization of detection of atomic absorption lines in intracavity laser spectroscopy

“…The ICL spectrometer with broadband tunable laser is very similar to that employed in conventional continuum source atomic absorption spectrometry [4]. In fact, apart from the primary light source, all other modules, analytical procedure and data processing re-V.S.…”

“…Dependence of the laser-induced fluorescence (dots) and optogalvanic signal (crosses) amplitudes on the spectral intensity of the laser radiation: discharge current !10 mA (curve 1), 20 mA (curves 2 and 3) and 30 mA(4) …”