Untersuchungen zur atomspektroskopischen spurenanalyse in AB-halbleiter-mikroproben—I : Verdampfbarkeit und unspezifische absorption von AB-verbindungen und ihren komponenten in der graphitrohrküvette

The evaporation of the species Ga³⁺, In³⁺, PO^3?₄, AsO^3?₄, Ga³⁺/AsO^3?₄, Ga³⁺/PO^3?₄ and In³⁺/AsO^3?₄ in HCl and HNO₃ medium was investigated by measurement of the non-specific absorption at 250 nm, in a graphite cuvette, with a continuum light source. The maximum of the non-specific absorption is given for the ashing and atomizing phases as a function of the ashing temperatures. Ashing temperatures for analytical determinations can be derived from the results. The mechanisms of evaporation of the substances were investigated by means of extinction-time curves. Absorption spectra of the matrices and of the pure acids used were measured between 190 and 330 nm in the graphite cuvette at different ashing and atomizing temperatures. The InCl- and GaCl-bands of the C-system and new bands of GaO- and InO-molecules were found. The PO-band at 246 nm was detected. The results are discussed and can be applied for thermal fractionation and for background correction by the two-line method in trace analysis by electrothermal AAS.