塑料 苯乙烯/丙烯腈共聚物 剩余的丙烯腈单体含量的测定 气相色谱法

[中文适用范围]： 该方法的原理是将供试品溶解于二甲基甲酰胺中，将少量溶液注入装有氢火焰离子化检测器的气相色谱仪中，分离检测挥发性成分。 溶剂含有已知量的丙腈或乙腈作为定量评价的内标。 使用该方法，可以预期共聚物中丙烯腈的检测下限约为 3 ppm。 为了获得 0.3 ppm 至 0.4 ppm 的较低检测限，附录 A 中规定了替代方法。 [外文原描述]： The principle of the method specified is dissolving a test portion in dimethylformamide and injecting a small volume of the solution into a gas chromatograph equipped with flame ionization detector to separate and detect the volatile components. The solvent contains a known amount of propionitrile or acetonitrile as an internal standard for quantitative evaluation. With this method, a lower detection limit of the order of 3 ppm of acrylonitrile in the copolymer may be expected. To obtain a lower detection limit of the order of 0,3 ppm to 0,4 ppm, an alternative method is specified in annex A.