This International Standard specifies a method for the determination of the bound acrylonitrile content of emulsion-polymerized NBR latices having a bound acrylonitrile content, expressed as a percentage of the polymer content, of between 18 % and 45 %. The method is also applicable to, for example, carboxylic-nitrile-butadiene (XNBR) latices and nitrile-isoprene (NIR) latices.