高效液相色谱法测定市售茶叶中8种人工合成色素及风险分析

Determination of 8 kinds of synthetic pigments in teas by high performance liquid chromatography and risk analysis

中文关键词:  茶叶  人工合成色素  高效液相色谱法  违规使用

英文关键词:tea  synthetic pigment  high performance liquid chromatography  illegal use

中文摘要:

      目的 建立高效液相色谱法测定茶叶中8种人工合成色素的分析方法, 利用该方法对市售茶叶进行检测分析, 以评估茶叶中人工合成色素违规应用的风险。方法 样品烘干揉碎后, 用1%氨水溶液, 超声提取, 离心, 利用PWAX固相萃取小柱净化, 以pH 6~7的水和甲醇淋洗, 5%氨化甲醇洗脱, 吹干后用水复溶, 过PTFE滤膜, 以多波长上机检测。结果 检出限0.1~0.3 mg/kg之间; 线性关系良好, 相关系数均在0.9999以上; 8种人工合成色素在茶叶中5倍检出限的添加, 平均回收率在88.2%~95.4%之间, 批内RSD在2.8%~5.7%之间; 利用该方法对市售的茶叶进行检测, 发现确有违规使用人工合成色素现象, 组分集中在柠檬黄、日落黄及胭脂红等, 检出浓度在2.5~1400 mg/kg之间。结论 该方法检出限低、线性良好、检测难度低、适合茶叶中人工合成色素的检则; 茶叶违规使用人工合成色素的现象需进一步评估, 适度监管, 确保茶叶的天然性。

英文摘要:

      Objective To establish a method for the determination of 8 synthetic pigments in teas by high performance liquid chromatography (HPLC) and to detect and evaluate the risk of illegal use of synthetic pigments in teas that were sold in the markets. Methods After the samples were dried and crushed, 1% aqueous ammonia solution was used for extraction by ultrasonic, centrifugation, and PWAX solid-phase extraction column was used for purification. Rinse with water (pH 6?7) and methanol in turn and eluted with 5% ammoniated methanol. After blow-drying, the samples were redissolved with water and passed through PTFE filters, then detected on the machine with multi wavelength. Results The detection limits were between 0.1 mg/kg and 0.3 mg/kg. The linear relationships were good, and the correlation coefficients were above 0.9999. The average recoveries of eight synthetic pigments in tea were between 88.2%?95.4% for 5-fold detection limit, and the in-batch RSD were between 2.8%?5.7%. The method was used to detect the commercial teas, and the illegal use of synthetic pigments were found. The components were tartrazine yellow, sunset yellow and carmine red, and the concentrations were 2.5? 1400 mg/kg. Conclusion The method has low detection limit, good linearity and low detection difficulty, which is suitable for the detection of illegal use of synthetic pigments in teas. It fills the blank of the method of synthetic pigment detection in teas. The illegal use of synthetic pigments in teas needs further evaluation and proper supervision to ensure the tea is nature.