Bacterial cell-to-cell communication, also called quorum sensing or autoinduction, is mediated by small molecules (autoinducers) amongst which the most frequently studied group is the N-acylhomoserine lactones (AHL).Because these autoinducers are mostly found in trace amounts, a sensitive method is required for their determination.The existing analytical methods for AHLs have limitations.1) Time consuming, costly and environment unfriendly liquid/liquid extraction was mostly employed.2)Bioassay has the shortage of low selectivity easily resulting in false positive confirmations due to interferences.3)Thin layer chromatography as a kind of cheap and fast chromatographic separation did improve the selectivity of bioassays, but is limited suitable for identification and semi-quantification.4) That all type of AHLs have high vapour tension and are unstable in the injector became a serious problem in sensitivity when GC was applied.5) LC is a theoretically and practically suitable technique for chromatographic separation, but separation of several AHLs simultaneously with traditional HPLC is time consuming (usually 30-40 min), and UV detection usually can not be applied because of the poor UV absorption of AHLs.