纳米固相微萃取应用于干红辣椒、水果饮料及红酒中罗丹明B的定量分析

制备了一种新型的聚苯乙烯纳米纤维, 将其作为固相萃取吸附剂装填制成固相萃取柱, 与高效液相色谱联用建立了干辣椒、 水果饮料及红酒中罗丹明B的定量分析方法. 高效液相色谱以3 g/L磷酸缓冲液-甲醇混合溶液(体积比3∶7, pH=7.0)为流动相. 通过对提取条件的优化, 得到该方法对干辣椒中罗丹明B的检出限为0.1 ng/g, 最低定量限为0.6 ng/g; 对水果饮料和红酒中罗丹明B的检出限均为0.2 ng/mL, 最低定量限均为0.5 ng/mL. 此方法对干辣椒中罗丹明B的提取回收率为98.2%~110.3%; 对水果饮料中罗丹明B的提取回收率为94.6%~102.2%; 对红酒中罗丹明B的提取回收率为90.4%~104.6%. 该方法的线性范围为1~100 ng/mL(ng/g), 相对标准偏差为2.3%~9.0%. 该方法灵敏度高、 选择性好, 可用于干辣椒、 水果饮料及红酒中罗丹明B的定量分析.

Application of Packed-nanofibers Solid-phase Extraction for Determination of Rhodamine B in Dry Chilli,Fruit Drink and Red Wine

A method for the determination of Rhodamine B in dry chilli, fruit drink and red wine was developed and validated.The analyte was extracted with acetonitrile from foodstuffs.A novel electrospun polymer nanofibers packed micro-column was used for cleaning and concentrating the Rhodamine B in these foodstuffs.High performance liquid chromatography with fluorescence detection(HPLC-Flu) was used for the determination of Rhodamine B in the samples. The mobile phase was composed of 3 g/L phosphate buffer and methanol(3∶7, volume ratio), the pH was adjusted to 7.0 with orthophosphoric acid.The results showed that the standard curve was linear over the validated concentrations range of 1-100 ng/mL(ng/g), and the limit of detection(LOD) for Rhodamine B spiked samples was 0.1 ng/g in dry chilli, 0.2 ng/mL in both fruit drink and red wine.The limit of quantitation(LOQ) for Rhodamine B spiked into dry chilli was 0.6 ng/g, fruit drink 0.5 ng/mL and red wine 0.5 ng/mL, respectively.The average recoveries of Rhodamine B were 98.2%-110.3% for dry chilli, 94.6%-102.2% for fruit drink, and 90.4%-104.6% for red wine, respectively.The relative standard deviation of the method was 2.3%-9.0%.This proposed method was applied to real samples including dry chilli, fruit drink as well as red wine, and there was no Rhodamine B found in fruit drink or red wine, but Rhodamine B was found in chilli powder.