提出了气相色谱-串联质谱法测定尼龙6树脂及其成型品中己内酰胺残留量的方法。样品经冷冻研磨仪粉碎后用甲醇超声提取,吹氮浓缩至1.0 mL后通过DB-WAX色谱柱分离,串联质谱测定。己内酰胺的质量浓度在0.005~5.0 mg·L-1范围内与其峰面积呈线性范关系;方法的检出限(3S/N)为0.002 mg·kg-1。在空白样品的基体中加入3个浓度水平的己内酰胺标准溶液做回收试验,测得回收率的平均值为88.8%~101%,测定值的相对标准偏差(n=6)为3.2%~7.0%。

A method of GC-MS/MS for the determination of residual amount of caprolactam in nylon 6 resin and its mouldings was proposed. The sample was smashed by freezing milling and extracted ultrasonically with methanol, and the extract was concentrated to 1 mL by N2-blowing. DB-WAX column was used for separation, and MS/MS was used for determination. Linear relationship between values of peak area and mass concentration of caprolactam was obtained in the range of 0.005-5.0 mg·L-1, with detection limit (3S/N) of 0.002 mg·kg-1. Recovery was tested by addition of caprolactam standard solution at 3 concentration levels, giving values of average recovery and RSD′s (n=6) in the ranges of 88.8%-101% and 3.2%-7.0% respectively.