Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Drop Combined with High Performance Liquid Chromatography for Determination of Chlorophenols in Aqueous Samples

Using the method of dispersive liquid liquid microextraction based on solidification of floating organic ( DLLME-SFO) combined with HPLC, three kinds of chlorophenols in aqueous samples were determined. The DLLME method with 1-dodecanol whose density was less than water and freezing point was 24 degrees C utilized as extractant and methanol as dispersive solvent was applied to analyze water samples. After the mixture was centrifugaled, the floated extractant that was solidified in ice bath was easily removed from water phase. When the solidified extractant droplet was redissolved, it was injected into the HPLC for analysis. The optimal experiment conditions were as follows: extractant solvent 200 mu L, dispersive solvent 300 mu L, NaCl 1. 2 g, 1 mol/L H3PO4 200 mu L, sample volume 8. 0 mL, extraction time 3 min. The calibration curve was linear in the range of 0. 05 - 6. 0 mg/L of the three kinds of chlorophenols, and the detection limits were 20 - 38 mu g/L. This method has been applied to the determination of real water samples, the recovery of standard additions were from 90. 11% to 107.7% and the inter-day RSDs were between 3.5% and 4.6%. The method extended the range of choosing the extractant in DLLME, it was proven to be simple, rapid, accurate and environment friendly.