Hollow fiber liquid-liquid-liquid microextraction followed by solid-phase microextraction and in situ derivatization for the determination of XXXX by gas chromatography-electron capture detection.

@entity24502 @entity211 @entity29359 @entity16648 @entity24011 @entity5828 @entity6674 @entity37125 @entity39512
UNASSIGNED: A method based on the combination of hollow fiber liquid-liquid-liquid microextraction and solid-phase microextraction (SPME) followed by gas chromatography-electron capture detection was developed for the determination of @entity16648 in water and wastewater samples. Silica microstructures fabricated on the surface of a stainless steel wire were coated by an organic solvent and used as a SPME fiber. The analytes were extracted through a hollow fiber membrane containing @entity37125 from sample solution to an alkaline aqueous acceptor phase. They were then extracted and in situ derivatized on the SPME fiber using @entity24011 . Experimental parameters such as the type of extraction solvent, acceptor phase @entity6674 concentration, donor phase @entity5828 concentration, the amount of derivatizing reagent, salt concentration, stirring rate and extraction time were investigated and optimized. The precision of the method for the analytes at 0.02-30 gL(-1) concentration level ranged from 7.1 to 10.2% (as intra-day relative standard deviation) and 6.4 to 9.8% (as inter-day relative standard deviation). The linear dynamic ranges were in the interval of 5-500 gL(-1), 0.05-5 gL(-1), 0.02-1 gL(-1) and 0.001-0.5 gL(-1) for @entity39512 , @entity29359 , @entity24502 and @entity211 , respectively. The enrichment factors were between 432 and 785. The limits of detection were in the range of 0.0004-1.2 gL(-1). Tap water, well water and wastewater samples were also analyzed to evaluate the method capability for real sample analysis.
