Ionic liquid based carrier mediated hollow fiber liquid liquid liquid microextraction combined with HPLC-ICP-MS for the speciation of phenylarsenic compounds in chicken and feed samples

A novel method of ionic liquid based carrier mediated hollow fiber liquid liquid liquid microextraction (IL-carrier 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 samples (pH = 10.2) into an organic phase (20% (v/v) [MTOA](+)[Cl](-) in toluene) impregnated in the pores of a hollow fiber, then back extracted into a 10 mu L acceptor phase of 0.3 mol L-1 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, 3 sigma) for five target phenylarsenic compounds and arsenate were in the range of 1.4-16.0 ng L-1 with the relative standard deviations (C-As(V),C-4-OH,C-3-NHPAA,C-PA,C-4-NPAA = 0.05 mu g L-1, Cp-ASA = 0.10 mg L-1, n = 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.