Cooling-Assisted Headspace Hollow Fiber-Based Liquid-Phase Microextraction Setup for Direct Determination of PAHs in Solid Samples by Using Volatile Solvents

摘要

To reinforce the extraction efficiency of the liquid- and solid-phase microextraction methods, different cooling-assisted setups have been employed, most of which are complicated, expensive, tedious, and do not show good performances due to indirect transfer of cold to the extraction phase. In this research, a simple, low-cost and effective cooling-assisted headspace hollow fiber-based liquid-phase microextraction (CA-HS-HF-LPME) device was fabricated and evaluated, which is able to directly cool down the extraction phase in different modes of LPME. It was coupled to GC-FID and utilized for the direct determination of PAHs in contaminated soil samples using volatile organic solvents. Different effective experimental variables including type and volume of extraction solvent, extraction time and temperature, and temperature of the cooled organic solvent were evaluated and optimized. Under the optimized experimental conditions (e.g., organic extracting solvent: 3 A mu L of acetone; extraction time: 20 min; extraction temperature: 90 A degrees C; and temperature of cooled organic drop: -25 A degrees C), good linearity of calibration curves (R (2) > 0.99) was obtained in a concentration range of 1-10,000 ng g(-1). The limits of detection (LODs) were obtained over the range of 0.01-0.1 ng g(-1). The relative standard deviations (RSD%, n = 6) of 0.1 A mu g g(-1) PAHs were found to be 4.7-10.1 %. The CA-HS-HF-LPME-GC-FID method was successfully used for the direct determination of PAHs in contaminated soil and plant samples, with no sample manipulation. The results were in agreement with those obtained by a validated ultrasound-assisted solvent extraction (UA-SE) method.