Separation, Concentration and Determination of Trace Thiamphenicol in Egg, Milk and Honey Using Polyoxyethylene Lauryl Ether-Salt Aqueous Two-Phase System Coupled with High Performance Liquid Chromatography

As a pretreatment technique to trace analysis, polyoxyethylene lauryl ether (POELE10)- salt aqueous two-phase extraction system (ATPES) is coupled with high performance liquid chromatography to analyse thiamphenicol (TAP) in egg, milk and honey. The analysis of the phase behaviors of the ATPES found that the extraction efficiency and enrichment factor of TAP was influenced by the types of salts, the concentration of salt, the concentration of POELE10, the concentration of 1-propanol and the temperature. The optimized conditions of experiment were determined in the multi-factor experiment by using response surface methodology. The extraction efficiency of TAP is up to 99.59% and the optimal values of enrichment factor of TAP was 27 under the optimized conditions. The limit of detection and the limit of quantification of TAP are 0.5 µg kg⁻¹ and 1.5 µg kg⁻¹, which meet the needs of determination of trace or ultratrace TAP in food.

Keywords
aqueous two-phase system; polyoxyethylene lauryl ether; trace thiamphenicol; determination