Accurate and reproducible determinations of total sulphur can be made following digestion of plant samples with a nitric/ perchloric acid mixture containing dichromate and metavanadate. Care should be taken to control digestion temperatures. The occurrence of dense fumes of perchloric acid and the deposition of red chromium trioxide are not satisfactory indicators of the digestion endpoint. Digestion for lh. beyond the change in colour of the digest from green to olive‐brown was necessary, in our work, for consistent results.