Sensitive determination of phenylarsenic compounds based on a dual preconcentration method with capillary electrophoresis/UV detection

摘要: A novel method based on off-line hollow fiber liquid microextraction (HF-LLLME) combined with on-column anion selective exhaustive injection (ASEI)-capillary electrophoresis/ultraviolet (CE/UV) detection was proposed for the speciation of five phenylarsenic compounds including phenylarsonic acid (PAA), 4-aminophenylarsonic (4-APAA), 4-hydroxyphenylarsonic (4-HPAA), 4-nitrophenylarsonic (4-NPAA) and 3-nitro-4-hydroxyphenylarsonic (NHPAA) in this paper. In HF-LLLME, target analytes were extracted from 5 mL aqueous samples (donor solution pH 2.15) through a thin phase tributyl phosphate (TBP) inside pores polypropylene finally into an 18 μL 0.8 mmol/L Tris acceptor lumen fiber. Following solutions directly analyzed by ASEI-CE/UV. For ASEI, large plug water (91% length total capillary) introduced separation capillary before sample order to prolong time, thus enhance stacking efficiency. Under optimized ASEI conditions, up 236-fold enrichment factor (EF) obtained ASEI-CE/UV determination compounds. By combining HF-LLLME ASEI-CE/UV, EFs ranging 155 1780-fold achieved limits (LODs) (at signal-to-noise ratio 3) range 0.68-6.90 μg/L compounds; relative standard deviations (RSDs) corrected peak area 5.6-11.8%. The HF-LLLME-ASEI-CE/UV applied pig feed local farm, storage litter, soil agricultural field lake collected near recoveries spiked 85.7-104.5%, 66.7-96.2%, 28.9-46.9% 86.9-107.8% feed, water, respectively.