ASTM D3533-90(2001)

1.1 This method outlines two procedures for the determination of total nitrogen in natural and synthetic rubbers and latexes, using variants of the Kjeldahl process.

1.2 It is applicable to raw rubbers, cured or uncured compounds, and finished articles.

1.3 Procedure A, the referee method, is a macro procedure. Procedure B, the alternative method, is a semimicro procedure using the same reagent as in Procedure A.

1.4 In the absence of other nitrogen-containing materials, the method can be used for the estimation of the NBR content of NBR rubbers and rubber products.

1.5 The values stated in SI units are to be regarded as the standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific warnings are given in 8.2 and 9.2.