固相萃取-高效液相色谱-可变波长检测法测定鲜榨果汁中7种水溶性合成着色剂

Determination of 7 kinds of water-soluble synthetic colorants in fresh juice by SPE-HPLC and variable wavelength detection

目的建立测定鲜榨果汁中7种水溶性人工合成着色剂(柠檬黄、苋菜红、日落黄、胭脂红、诱惑红、亮蓝、赤藓红)的聚酰胺固相萃取-高效液相色谱分析方法。方法采用无水乙醇-氨水-水提取液对鲜榨果汁中7种水溶性人工合成着色剂进行提取,聚酰胺固相萃取柱净化和富集,以甲醇-0.02 mol/L乙酸铵为流动相,梯度淋洗分离,多波长检测定量。结果 7种水溶性人工合成着色剂在1.0μg/ml^50.0μg/ml线性关系良好,相关系数>0.999 90,回收率为89.4%~96.6%,RSD为0.9%~3.7%,检出限为0.05 mg/kg^0.10 mg/kg。结论本法适合基质复杂有大量沉淀的饮品,前处理方法简便、回收率高、方法重复性满足实验要求。

Objective To establish a method for determination of 7 kinds of water - soluble synthetic colorants （ lemon yellow, amaranth, sunset yellow, carmine, red, blue, erythrosine） in fresh juice by solid phase extraction（SPE） and high performance liquid chromatography（HPLC） with variable wavelengths detection. Methods The mix ethanol -ammonia -water solution was used to extract the synthetic colorants from fresh juice, then purified and concentrated with polyamide solid phase extraction. Sample solutions were separated with methanol and acetic ammonium solution（0.02 mol/L） mixture as mobile phase in the gra- diem elution mode, and multiple wavelengths were used to qualify. Results The linear range of the method was 1.0 μg/ml ～ 50.0 μg/ml, with the correlation coefficients greater than 0. 999 90. The recoveries of the method were in the range of 89.4% to 96.6%, and the relative standard deviations（RSD） was from 0.9% to 3.7%. The limits of detection were from 0.05 mg/kg to 0.10 mg/kg. Conclusion The method is simple, rehable and reproducible, especially suitable for detection of water - solu- ble synthetic colorants in fresh juice.