Determination of Nitrogen, Sulphur, Phosphorus, Potassium, Sodium, Calcium, and Magnesium in Plant Material by Automatic Analysis

摘要

Methods are proposed for the rapid determination of nitrogen, sulphur, phosphorus, potassium, sodium, calcium, and magnesium in plant material by automated chemical analysis. Phosphorus, potassium, calcium, magnesium, and sodium are determined in nitric-perchloric-sulphuric acid digests and may be determined simultaneously if desired. For nitrogen and sulphur separate treatments of the sample materials are used. A modified Kjeldahl digestion is used for nitrogen, on which phosphorus may also be determined simultaneously, and a combustion of the sample in an oxygen flask is used for the determination of sulphur. Results of analyses of a range of plant materials by the automatic procedures compared satisfactorily with results obtained by conventional chemical methods. (Author)