Determination of partition coefficient and analysis of nitrophenols by three‐phase liquid‐phase microextraction coupled with capillary electrophoresis

Abstract

A three-phase hollow fiber liquid-phase microextraction method coupled with CE was developed and used for the determination of partition coefficients and analysis of selected nitrophenols in water samples. The selected nitrophenols were extracted from 14 mL of aqueous solution (donor solution) with the pH adjusted to pH 3 into an organic phase (1-octanol) immobilized in the pores of the hollow fiber and finally backextracted into 40.0 microL of the acceptor phase (NaOH) at pH 12.0 located inside the lumen of the hollow fiber. The extractions were carried out under the following optimum conditions: donor solution, 0.05 M H(3)PO(4), pH 3.0; organic solvent, 1-octanol; acceptor solution, 40 microL of 0.1 M NaOH, pH 12.0; agitation rate, 1050 rpm; extraction time, 15 min. Under optimized conditions, the calibration curves for the analytes were linear in the range of 0.05-0.30 mg/L with r(2)>0.9900 and LODs were in the range of 0.01-0.04 mg/L with RSDs of 1.25-2.32%. Excellent enrichment factors of up to 398-folds were obtained. It was found that the partition coefficient (K(a/d)) values were high for 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol and 2,6-dinitrophenol and that the individual partition coefficients (K(org/d) and K(a/org)) promoted efficient simultaneous extraction from the donor through the organic phase and further into the acceptor phase. The developed method was successfully applied for the analysis of water samples.

Dispersive liquid-liquid microextraction of phenolic compounds using solidified floating organic droplets, and their determination by HPLC

“…To investigate the effect of sample volume, different volume (5,6,7,8,9, and 10 mL) of sample were studied. It was found that the largest analytical response was obtained when 6 mL of sample solution was used.…”

“…Up to now, various pretreatment techniques have been developed to extract phenolic compounds from aqueous samples, such as solid-phase extraction (SPE) [5], solidphase microextraction (SPME) [6][7][8], single-drop microextraction (SDME) [3] and hollow-fiber liquid-phase microextraction (HF-LPME) [9]. However, SPE requires large volumes of toxic solvent, and the process is complicated and time-consuming [10].…”

Design, Synthesis, and Antimycobacterial Property of PEG–bis(INH) Conjugates

“…The partition coefficient of the labeled complexes was measured separately by determining the partition coefficients between the organic and aqueous phases (18). From the solution of the labeled compound, 0.1 mL was added to a biphasic mixture of 1.9 mL of water and 2 mL of n-octanol, respectively.…”

Derivatization following hollow-fiber microextraction with tetramethylammonium acetate as a dual-function reagent for the determination of benzoic acid and sorbic acid by GC

“…HF-LLLME with NaOH as the acceptor solution has been widely used for the determination of acidic analytes [30][31][32][33]. However, if an organic alkali reagent is used instead of NaOH, it can not only be an acceptor solution for the extraction of acidic analytes owing to its alkalinity but also a derivatization reagent for the acidic analytes in the GC injection port at the same time.…”