Measurement of the Phenols in Water by Electro-Assisted Solid Phase Microextraction

A new electro-assisted solid phase microextraction (EA-SPME) technique using the lab-made fiber has been developed to sample phenols in water before gas chromatographic (GC) analysis. The EA-SPME cell is composed by two electrodes: the working electrode is a SPME fiber and the counter-electrode is a piece of platinum (Pt) wire. The cell was used to extract and measure phenolic pollutants including phenol, 2-chlorophenol (2-CP) and 2, 4-dichlorophenol (2, 4-DCP). Results showed that positive and negative voltages exert different impact on the adsorption of the compounds. For example, the adsorptive capacity of phenol under 1.5 voltages was 1.1 times to bare adsorption. But positive or negative voltages could make hindrance to the adsorption of 2-CP at about 13% at voltages was 1.5 V and -1.5 V, respectively. The adsorption of 2, 4-DCP was enhanced both under the positive and negative voltages loaded, and the adsorption was 1.25 times at 1.3 V to that with no voltages added. Operational parameters besides working voltages, pH, electrolyte and analyte concentrations were also surveyed and optimized. The most phenols could be sampled and analyzed by the EA-SPME method.