液液萃取-场放大进样-毛细管电泳非接触式电导分离检测酱油中的安赛蜜

采用场放大进样（FASI）-毛细管电泳非接触式电导检测法（CE-C⁴D），结合液液萃取（LLE）的样品净化预处理技术，分离检测了酱油中人工合成甜味剂安赛蜜。酱油样品经酸化后，用乙酸乙酯作为萃取剂，成功地消除了酱油中含有的大量无机盐等复杂基体对微量安赛蜜的干扰。实验对影响LLE萃取效率和FASI-CE-C⁴D分离检测的关键因素进行了讨论，特别是对样品净化前处理过程中萃取剂及用量、样品酸化pH值、萃取时间、萃取温度等条件进行了优化。结果表明，酱油中的安赛蜜可获得良好分离和灵敏检测，检出限和定量限分别为0.15 mg/kg和0.48 mg/kg。对市售酱油样品进行安赛蜜的加标回收测定，得到加标回收率为92.3%~108.1%，相对标准偏差＜8.0%。该法具有简单快速、灵敏高效、分析成本低的优点，能满足酱油中安赛蜜的分析检测要求。

Separation and determination of acesulfame-K in soy sauce by capillary electrophoresis with contactless conductivity detection using liquid-liquid extraction and field-amplified sample injection

A new method was established for the sensitive determination of artificial synthetic sweetener acesulfame-K in soy sauce by capillary electrophoresis (CE) with field-amplified sample injection (FASI)and capacitively coupled contactless conductivity detection (C⁴D). Liquid-liquid extraction (LLE) technology was employed to eliminate the complex matrix interference co-existing in soy sauce. Ethyl acetate was used as the extraction solution. The pH of the sample solution was adjusted to 1.7, and both inorganic salts and organic compounds causing interferences were effectively removed by LLE. The type and volume of the extraction solvents, pH of the sample solutions, extraction method and extraction time were investigated in detail. Under the optimized experimental conditions, acesulfame-K in soy sauce was well separated and sensitively detected. The limit of detection and limit of quantification were 0.15 mg/kg and 0.48 mg/kg, respectively. The accuracy was tested by spiking acesulfame-K into soy sauce samples, and the recoveries ranged from 92.3% to 108.1%. The relative standard deviations were below 8.0%. The proposed method can meet the requirements for the fast screening and sensitive detection of acesulfame-K in soy sauce samples.