Atomisation of selenium hydride in the graphite furnace

Abstract

Atomisation of selenium hydride in a graphite furnace was investigated and compared with the atomisation in a flame-in-tube atomiser of the same dimensions. Continuous flow hydride generation was used because it produces a steady-state atomic absorption signal. Graphite and quartz interfaces for hydride introduction into the graphite furnace are evaluated. The results indicate two independent mechanisms of hydride atomisation in a graphite furnace: (i) a low-temperature mechanism that is effective only in the presence of oxygen, which is probably similar to that in quartz tube atomisers, and (ii) a high-temperature mechanism that is independent of oxygen. The sensitivity for selenium in graphite furnaces is considerably lower than in flame-in-tube atomisers. However, the extreme reproducibility of signals obtained with low-temperature atomisation is promising for routine applications.