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.
BS 7164-21:1996 history
2014BS ISO 1656:2014 Rubber, raw natural, and rubber latex, natural. Determination of nitrogen content
1996BS 7164-21:1996 Chemical tests for raw and vulcanized rubber - Determination of nitrogen content
0000 BS 7164 Sec.6.1:1994
1990BS 7164 Pt.21:1990 Chemical tests for raw and vulcanized rubber. Determination of nitrogen content
1981BS 5923 Pt.3:1981 Methods for chemical analysis of rubber. Determination of volatile matter content of raw rubbers