Evaluation of totally pyrolytic graphite cuvettes for electrothermal atomic-absorption spectrometry

Abstract

Owing to the problems, such as porosity and carbide formation, encountered with conventional electrographite furnace tubes, a study has been undertaken to select an alternative material that would overcome them. The suitability of several materials was evaluated and pyrolytic graphite has been selected as the best material for tube manufacture. The results of a series of tests carried out using V, Mn and Pb, as typical of the elements determined using the graphite furnace, are discussed to assess the advantages. Performance, with regard to constant chemical sensitivity, tube lifetime and precision, is indicated. Results obtained with a sample type known to give analytical problems in the past are used to validate the findings. Pyrolytic graphite tubes provide improved lifetimes, heating rates and power requirements compared with existing furnace tube materials and may be used in existing furnace power supply units without modification.