This International Standard specifies a macro-method and a semi-micro method for the determination of ni-trogen in raw natural rubber and in natural rubber latex using variants of the Kjeldahl process.
NOTE 1 The determination of nitrogen in natural rubber is usually carried out in order to arrive at an estimate of the protein content. Minor amounts of non-proteinous nitrogen-containing constituents are also present, however, and in the dry solids prepared from natural rubber latex these ma-terials can make a substantial contribution to the total nitro-gen content.