Determination of vanadium, chromium and molybdenum by atomic absorption spectrometry using a graphite furnace coated with boron

Vanadium, chromium and molybdenum were determined by atomic absorption spec trometry with a coated graphite furnace. Pyrolytic graphite tubes were coat ed with boron carbide. A mixture of nitrates of nickel and strontium and bo ric acid was then added to a sample solution as a matrix modifier. Using th is coated tube, the determinations of vanadium, chromium and molybdenum wer e successful with high sensitivity and better reproducibility. No interfere nce from metal nitrates and chlorides with vanadium and molybdenum determin ations and from metal nitrates with chromium determination was observed. Th e chloride interference with chromium and the sulfate interference with ana lyte could be removed by adding ammonium salt of EDTA.