摘要

A new, rapid, and inexpensive method using two-step ultrasonic assisted liquid-liquid micro-extraction (UALLME) coupled with capillary electrophoresis-ultraviolet (CE-UV) was developed for 5-hydroxymethylfurfural (HMF) analysis in high ion strength samples (like vinegar and soy sauce). The factors affecting the extraction efficiency were optimized such as the extraction volume, the ultrasonic time, and the power density of ultrasonic. Under the optimum conditions, the limit of detection (LOD) and the limit of quantification (LOQ) for HMF were 0.03 and 0.10 mg/L, respectively. The relative standard deviations (RSD %) for HMF were ranging from 0.53 to 3.17%, and the recoveries of HMF were ranging from 91.24 to 109.39%. The results turned out that two-step UALLME-CE-UV was applicable to analyze HMF in vinegar and soy sauce. Eleven brands of vinegar and soy sauce were tested by two-step UALLME-CE-UV, and the results showed that the method had a potential application in analysis of foodstuffs. The two step UALLME method was effective to improve the selectivity and sensitivity of CE-UV method for HMF analysis in vinegar and soy sauce.