Rapid decomposition of heterocyclic ring compounds with molten acidic lithium sulphate flux containing catalysts and kjeldahl determination of nitrogen.

Heterocyclic ring compounds such as pyrazine, pyrimidine, purine, quinoxaline, quinazoline and phthalazine can be rapidly decomposed in the molten state with mixtures of various ratios of concentrated sulphuric acid and lithium sulphate (molten ALS) flux containing catalysts such as cupric sulphate, elemental selenium powder, selenium dioxide, mercury(II) oxide (red) and mercurcic sulphate. The quantitative recovery of nitrogen in the above six compounds with the molten ALS flux decomposition systems can be obtained with the Kjeldahl method.