1994年2月10日，环境保护局提出了信息收集规则（ICR），要求公共供水开始监测几种消毒副产品。特别令人感兴趣的是氯化氰，这是氯化自来水中由于氯胺与天然有机物（即腐殖酸和黄腐酸）反应而形成的副产品。直到最近，商业实验室还不能方便地获得氯化氰的标准。过去的实验室必须使用非常特殊的处理预防措施来处理这种气体形式的剧毒化合物。在EPA方法524.2规定的条件下，通过气相色谱/离子阱质谱法分析氯化氰时，发现其从色谱柱中洗出，非常接近EPA规定的化合物氯乙烯。根据单独的吹扫和捕集设置以及使用的GC柱，分析物之间的保留时间差在3到10秒之间。 在离子阱中，氯氰的质谱几乎与氯乙烯的质谱完全相同，这很容易导致经验丰富的GC/MS化学家误判任何一种化合物。本文的目的是研究导致形成与氯乙烯相同的氯化氰质谱的机理和条件。此外，印第安纳州瓦尔帕莱索市一家水处理厂的设计和水处理化学品将与处理水中氯化氰的形成有关。初步证据表明，经过处理的水中氯化氰的形成可能部分是由于水处理化学品之间的反应。

On February 10, 1994, the EPA proposed the Information Collection Rule (ICR), which will require public water supplies to begin monitoring for several disinfection byproducts. Of particular interest is cyanogen chloride, a byproduct formed in chlorinated tap water due to the reaction between chloramines and naturally occurring organic substances (i.e. humic and fulvic acids). Until recently, standards for cyanogen chloride were not conveniently available to commercial laboratories. A lab in the past would have to handle this very toxic compound in a gaseous form using very special handling precautions. When cyanogen chloride is analyzed by gas chromatography/ion trap mass spectrometry under the conditions specified in EPA Method 524.2, it was found to elute from the column very close to an EPA regulated compound, vinyl chloride. Depending upon the individual purge and trap setup and GC column used, the retention time difference between the analytes ranges from 3 to 10 seconds. In the ion trap, the cyanogen chloride mass spectrum is virtually identical to that of vinyl chloride, which may easily lead an experienced GC/MS chemist to misidentify either compound. The purpose of this paper is to examine the mechanism and conditions that lead to the formation of a mass spectrum for cyanogen chloride that looks identical to that of vinyl chloride. Also, the design and water treatment chemicals used at a water treatment plant in Valparaiso, Indiana, will be discussed in relation to the formation of cyanogen chloride in treated water. Preliminary evidence indicates that the formation of cyanogen chloride in treated water may be due in part to reactions among the water treatment chemicals themselves.