高效液相色谱法测定奶酪和人造黄油中胭脂树橙残留

High performance liquid chromatography determination of annatto residues in cheese and margarine

目的:应用高效液相色谱法测定奶酪和人造黄油中胭脂树橙(降红木素和红木素)残留。方法:试样经冰醋酸+乙腈(3+7)溶液提取,低温冷冻后高速离心,过滤,用高效液相色谱仪,C18柱,流动相为乙腈+0.1甲酸溶液(92+8),流速为1.0 m l/m in,紫外检测波长为460 nm。结果:溶剂、降红木素、红木素可达到基线分离,降红木素和红木素在0.05 mg/L^2.00 mg/L浓度范围内线性良好,相关系数r均大于0.99,对奶酪、人造黄油样品分别进行浓度0.5 mg/kg、1 mg/kg、5 mg/kg的添加回收实验,结果表明,胭脂树橙的平均回收率在92.0%~108%之间,相对标准偏差0.8%~9.9%(n=6)。方法的定量限为0.5 mg/kg。结论:本法准确、可靠、简便,检测限低,适用于奶酪和人造黄油中降红木素和红木素的同时分析测定。

Objective：A high performance liquid chromatography method was developed for determination of annatto（norbixin and bixin） residues in cheese and margarine.Methods： Cheese or margarine was extracted with glacial acetic acid＋acetonitrile（3＋7）,low temperature freeze,centifugation and filter.Analysis was performed using HPLC systems equipped with a C18 column and a UV detector at 460 nm with a mobile phase of acetonitrile ＋0.1% formic acid solution（92＋8）,at a flow rate of 1.0 ml/min.Results： The solvent,norbixin and bixin were separated each other.Good linearities were observed in the range of 0.05 mg/L～2.00 mg/L with correlation coefficients above 0.99.The average recoveries in cheese and margarine were in the range of 92.0%～108% at three spiked levels of 0.5 mg/kg,1 mg/kg and 5 mg/kg and the relative standard deviations were in the range of 0.8 %～9.9 %（n=6）.The limits of quantitative were 0.5 mg/kg.Conclusion： The method has the advantages of simplicity and repeatability and sessitivity,and can be used for simultaneous analysis of norbixin and bixin in cheese and margarine.