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A novel method by combining hollow fiber-liquid-liquid-liquid microextraction (HF-LLLME) with HPLC-ICP-MS was developed for the speciation of inorganic mercury (Hg 2+ ) and organomercury including methylmercury (MeHg + ), ethylmercury (EtHg + ) and phenylmercury (PhHg + ), in the microecosystem of East Lake (Wuhan, China). The factors affecting HF-LLLME were systematically investigated.Under the optimized conditions, the limits of detection for four mercury species were in the range of 2.9-5.6 ng L À1 with the relative standard deviations (c ¼ 0.5 mg L À1 , n ¼ 7) ranging from 5.6 to 10.6%. The developed method was validated by analyzing a certified reference material of DORM-2, and the determined values were in good agreement with the certified values. The method has been applied for the speciation of mercury in five representative samples from the micro-ecosystem of East Lake including atmospheric particles, lake water, fish, plant and sediment.

A novel method of ionic liquid based carrier mediated hollow fiber liquid liquid liquid microextraction (ILcarrier mediated HF-LLLME) combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) has been developed for the speciation of five phenylarsenic compounds and arsenate in chicken and feed samples. The target arsenic species were extracted from 6 mL aqueous samplesimpregnated in the pores of a hollow fiber, then back extracted into a 10 mL acceptor phase of 0.3 mol L À1 NaBr in the lumen of the hollow fiber. The main driving force for the extraction was the gradient concentration of the counter ion from the donor phase to the acceptor phase. Factors affecting the extraction of the target arsenic species were investigated in detail. Under the optimal conditions, the limits of detection (LODs, 3s) for five target phenylarsenic compounds and arsenate were in the range of 1.4-16.0 ng L À1 with the relative standard deviations (C As(V),4-OH,3-NHPAA,PA,4-NPAA ¼ 0.05 mg L À1 , C p-ASA ¼ 0.10 mg L À1 , n ¼ 7) ranging from 3.6 to 10.0%, and the enrichment factors were varied from 86 to 372-fold. The proposed method of IL-carrier mediated HF-LLLME-HPLC-ICP-MS was successfully applied to the determination of five phenylarsenic compounds and arsenate in chicken and feed samples with the recoveries of 79.2-105.4% and 81.1-117.8% for the spiked chicken and spiked feed samples, respectively.

MSPE combined with HF-LLLME for speciation of seleno-amino acids with high EFs and good anti-interference ability.