In recent years, hollow fiber based liquid-liquid-liquid micro-extraction (HF-LLLME) [1] has been widely studied due to its higher enrichment factor, excellent ability of clean-up, and lower consumption of organic solvent.In HF-LLLME, the driving force for analytes transferring from donor phase through organic phase into acceptor phase is the essential factor for HF-LLLME to obtain fast extraction with a high enrichment factor.By far, the driving force most widely used for HF-LLLME is pH gradient between donor phase and acceptor phase [2-4].Donor phase is adjusted to favor the deionization of analytes and distributing into organic phase, while the acceptor phase is adjusted to favor the analytes ionization and dissolving in acceptor.Actually, the ion strength gradient is also used as an auxiliary driving force when pH gradient is used [3].The composition of organic phase is another critical factor that influences the selectivity and clean-up ability of HF-LLLME.The long extraction time toreach equilibrium and the low extraction recovery are the major disadvantages of HF-LLLME [2].