柱前衍生/高效液相色谱法测定烟用添加剂中的咪唑

Determination of Imidazole in Cigarette Additives by High Performance Liquid Chromatography with Pre-column Derivatization

建立了丹磺酰氯柱前衍生/高效液相色谱(HPLC)测定烟用添加剂中咪唑含量的分析方法。添加剂样品经碳酸盐缓冲溶液处理,丹磺酰氯进行柱前衍生化后,再经乙酸乙酯萃取,取有机层萃取液经干燥、过滤、浓缩、乙腈定容、过滤后,以C18柱为色谱柱,乙腈-水为流动相梯度洗脱,荧光检测器检测。确定最佳的衍生化反应条件为:丹磺酰氯溶液质量浓度1 000 mg/L,反应温度45℃,缓冲溶液p H值10. 0,超声振荡反应时间40 min,咪唑衍生物用外标法进行定量分析。该方法在0. 5~500 mg/L范围内线性关系良好,相关系数(r)为0. 999 5,对咪唑的检出限为0. 24 mg/kg,定量下限为0. 80 mg/kg,0. 5、10. 0、500 mg/L 3个加标水平下的回收率为89. 1%~97. 2%,相对标准偏差不大于7. 5%。该方法准确可靠,适用于烟用添加剂中咪唑含量的测定。

An effective method of high-performance liquid chromatography(HPLC)was developed for the determination of imidazole,the harmful ingredient in cigarette additives based on pre-column derivatization with dansyl chloride(Dns-Cl).The additive samples firstly underwent the treatment of a buffer of carbonate solution,followed by the pre-column derivatization with dansyl chloride,then the extraction with ethyl acetate,dryness,evaporation,dilution with acetonitrile and filteration,separation on a C 18 column,elution with acetonitrile-water by gradient elation,and finally the detection with a fluorescence detector.The optimum derivatising conditions of imidazole with dansyl chloride are as follows:concentration of dansyl chloride:1 000 mg/L;temperature of reaction:45℃;pH of buffer solution:10.0;time of reaction:40 min.The imidazole derivative was quantified by the external standard method.There was a good linearity for the analyte in the range of 0.5-500 mg/L with a correlation coefficient of 0.999 5.The limits of detection of the method for imidazole derivative was 0.24 mg/kg,and the limits of quantitation was 0.80 mg/kg.The recoveries at three spiked levels ranged from 89.1%to 97.2%with RSDs not more than 7.5%.Results showed that the method was accurate and reliable,and was applicable to the determination of imidazole content in cigarette additives.