涂覆型不锈钢丝固相微萃取/高效液相色谱联用测定豆腐乳中的苏丹红

Determination of Sudan Dyes in Fermented Bean Curd by SPME/HPLC Using Coated Stainless Steel Fiber

采用原位聚合法在经修饰的不锈钢丝表面键合甲基丙烯酸丁酯-乙二醇二甲基丙烯酸酯（BMA-EDMA）材料,制作了不锈钢丝固相微萃取（SPME）纤维,与高效液相色谱（HPLC）联用测定了豆腐乳中的苏丹红Ⅰ,Ⅱ,Ⅲ.系统考察了萃取时间、解吸时间、盐浓度等实验条件对萃取效率的影响,建立了测定豆腐乳中苏丹红的SPME/HPLC方法.实验结果表明,3种苏丹红化合物的线性范围为50～1 000 μg/L,线性相关系数（r2）不低于0.923 2,检出限为0.303～1.808 μg/L.方法的柱内（n=3）和柱间（n=6）精密度（RSD）分别不大于9.2％和16.5％,实际样品的加标回收率为79.5％～86.4％.所制备的不锈钢丝萃取头机械强度高、操作简便、稳定性好、成本低;方法快速、灵敏,适用于豆腐乳中苏丹红的测定.

An in-situ polymerization method was used in the preparation of a novel solid-phase microextraction（SPME） coating,where butyl methacrylate-ethylene glycol dimethacrylate（BMA-ED-MA） was directly bonded to the surface of a modified stainless steel wire.Coupled with high performance liquid chromatography（HPLC）,the prepared coating was applied in the extraction and determination of sudan Ⅰ,Ⅱ,Ⅲ dyes in fermented bean curd.The experimental conditions for SPME,including extraction time,desorption time and salt concentration were optimized.As a result,the linear relationships（r2 ≥0.923 2） between concentrations of 50 μg/L and 1 000 μg/L for sudan Ⅰ,Ⅱ,Ⅲ dyes were obtained.The limits of detection ranged from 0.303 μg/L to 1.808 μg/L.the run-to-run（n =3） and fiber-to-fiber（n =6） relative standard deviations of this method were no more than 9.2％ and 16.5％,respectively.The spiked recoveries of three dyes were in the range of 79.5％-86.4％.The prepared stainless steel fiber possessed some advantages including high mechanical strength,simplicity,good stability and low cost.The method was fast and sensitive,and was suitable for the determination of sudan dyes in fermented bean curd.