高效液相色谱-荧光法测定大米中11种双三嗪氨基二苯乙烯荧光增白剂方法的优化

Optimization of the determination of 11 kinds of bis(triazinyl) aminostibene fluorescent whitening agents in rice by high performance liquid chromatography-fluorescence method

目的优化高效液相色谱-荧光检测法同时测定大米中11种双三嗪氨基二苯乙烯荧光增白剂的方法。方法大米样品经甲醇-水-氨水(60:39:1)提取,提取液用初始流动相稀释后,利用Waters Symmetry C18柱(250 mm×4.6 mm, 5μm)分离并进行液相色谱测定;以甲醇和25 mmol/L四丁基溴化铵溶液为流动相梯度洗脱,外标法定量。结果在优化条件下, 11种荧光增白剂在0.005~0.100μg/mL的浓度范围内线性关系良好,相关系数均大于0.999,检出限为0.002~0.009 mg/kg。当加标水平为0.1、0.4、2.0 mg/kg时, 11种荧光增白剂的平均回收率为72.0%~92.0%,相对标准偏差为为0.6%~6.8%。结论该方法操作简便,灵敏度高,重现性好,可应用于大米中二苯乙烯类荧光增白剂的检测。

Objective To optimize the method for the simultaneous determination of 11 kinds of bis(triazinyl) aminostibene fluorescent whitening agents in rice by high performance liquid chromatography-fluorescence detection(HPLC-FLD). Methods The fluorescent brighteners in rice samples were extracted with methanol-water-ammonia(60:39:1, V:V:V), diluted with initial mobile phase. The separation was performed on Waters Symmetry C18 column(250 mm×4.6 mm×5 μm) by gradient elution using methanol and 25 mmol/L TBA solution as the mobile phases. The results were quantified by the external standard method. Results Under the optimized conditions, the 11 fluorescent brighteners showed good linear relationships within the concentration range of 0.005-0.100 μg/mL, and the correlation coefficients were all greater than 0.999. The limits of detection were 0.002-0.009 mg/kg. When the standard levels were 0.1, 0.4 and 2.0 mg/kg, the average recoveries of 11 fluorescent brighteners were 72.0%-92.0%, and the relative standard deviation was 0.6%-6.8%. Conclusion The method is simple to operate, has high sensitivity and good reproducibility, and can be applied to the detection of stilbene fluorescent whitening agents in rice.