Continuum-source atomic absorption spectroscopy with an echelle spectrometer adapted to a charge injection device.

An instrumental system for continuum-source atomic absorption spectroscopy has been developed for simultaneous multielement determinations. The system consists of an electrothermal atomizer and a charge injection device adapted to an echelle spectrometer to achieve multiplex detection. A continuous 40-nm spectral range in the two-dimensional echelle spectrum was acquired simultaneously through the capability of the charge injection device to integrate signals in its MOS capacitors. Novel methods were developed to compute absorbances by "scanning" through all orders in the entire echelle spectrum or selecting absorption lines randomly. In the range 300-430 nm, characteristic concentrations (1% absorption) were 1.6, 2.6, 2.9, and 3.8 ng mL-1 respectively for Cu, Mn, and two Cr lines; these values are similar to those (1.3, 2.2, 1.2, and 3.6 ng mL-1) obtained for single-element detection with an image-dissector system.