微波辐射辅助快速检测微量亚硝胺的研究

分析了分光光度法对于溶液中亚硝胺回收率过低的原因，发现去亚硝基化反应 产物NOBr在吹离溶液过程中分解成为光度法无法检测的NO_x（x < 2）鉴于此，在 装置中增加一个CrO_3氧化管，将生成的NO_x（x < 2）转化成可被显色检测的 NO_2，使亚硝胺回收率高于90%，接近公认标准方法－热能分析仪（TEA）法的类似 指标（76% ～ 96%）；而检测限可达2 * 10~(-8) mol/L。发现微波辐射能使亚硝 胺在低于其沸点的温度下挥发和/或分解，并将其用于倩光度法检测，可以在3 min之内将样品中的亚硝胺收集以供测定，形成快速同时检测环境样品（如烟草） 中微量亚硝胺和氮氧化物的新方法。

Investigation on fast Determination of Trace N-Nitrosamines Assisted by Microwave Radiation

The spectrophotometric determination of trace N-nitrosamines in solution was investigated in order to enhance its recovery and sensitivity. Based on the investigation on the recovery below 10% in this method, the reason was found relating to formation of spectrophotometric invisible NO_x (x < 2) species such as NO. Consequently an oxidation tube was added in the instrument to convert these NO_x species into the detectable NO_2, therefore the recovery for N-nitrosamine with concentration of 2 * 10~(-5) ～ 2 * 10~(-8) mol/L could be increased to 80% ～ 98%, close to that of thermal energy analyzer (76% ～ 96%). On the other hand, resulting from the discovery that many N-nitrosamines could be evaporated under microwave radiation, a new method combining microwave radiation with the improved spectrophotometric method was thus reported for determining both N-nitrosamines and nitrogen oxides in tobacco and tobacco products. Within 3 minutes both N-nitrosamines and nitrogen oxides in tobacco or tobacco products could be collected for detection.