氯和硫、磷、砷等一样是对氨合成催化剂有害的元素,所以氯的测定对氨合成催化剂的生产控制及其质量鉴定都十分重要。对氨合成催化剂中微量氯的测定已有报导。其方法是用硝酸溶样,使氯转化为氯化氢,气化分离,然后用硫氰酸汞分光光度法进行测定,共要蒸馏三次,测定三次,方能得到结果。操作麻烦,同时硫氰酸汞有毒。本文应用作者提出的“Gran滴定增量法”进行测定,方法灵敏度(0.035PPm)高 Chlorine and sulfur, phosphorus, arsenic and other elements are harmful to the ammonia synthesis catalyst, so the determination of chlorine on the ammonia synthesis catalyst production control and quality identification are very important. Determination of traces of chlorine in ammonia synthesis catalysts has been reported. The method is to dissolve the sample with nitric acid to convert the chlorine into hydrogen chloride, gasify and separate, and then measure with mercury thiocyanate spectrophotometry, totally three times of distillation and three times of measurement to obtain the result. Operation is troublesome, while mercuric thiocyanate is toxic. In this paper, the “Gran titration incremental method” proposed by the author was used to determine the sensitivity of the method (0.035PPm)