ISO 1656:2019 PDF

Scope: This document specifies a macro-method and a semi-micro method for the determination of nitrogen in raw natural rubber and in natural rubber latex using variants of the Kjeldahl process. NOTE 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, in the dry solids prepared from natural rubber latex, these materials can make a substantial contribution to the total nitrogen content.

ISO 1656:2019 Referenced Document

ISO 123 Rubber latex - Sampling
ISO 124 Latex, rubber - Determination of total solids content
ISO 1795 Rubber, raw natural and raw synthetic - Sampling and further preparative procedures

2019 ISO 1656:2019 Rubber, raw natural, and rubber latex, natural — Determination of nitrogen content
2014 ISO 1656:2014 Rubber, raw natural, and rubber latex, natural - Determination of nitrogen content
2012 ISO 1656:1996 Rubber, raw natural, and rubber latex, natural — Determination of nitrogen content
1988 ISO 1656:1988 Rubber, raw natural, and rubber latex, natural; determination of nitrogen content
1974 ISO 1656:1974 Raw natural rubber and natural rubber latex — Determination of nitrogen