Determination of Phenols in Wastewater by Dispersive Liquid-Liquid Microextraction Coupled to Capillary Gas Chromatography

A simple and reliable method combining dispersive liquid-liquid microextracion (DLLME) with capillary gas chromatography (GC) using flame ionization detection was developed for simultaneous determination of phenol (PN), p-methyl phenol (p-MPN), o-nitrophenol (oNPN), and 2, 4-dichlorophenol (DCPN) in wastewater. To achieve this goal, dispersive liquid-liquid microextraction (DLLME) was applied as a sample preparation technique. The DLLME conditions such as the types and volume of extraction solvent, the types and volume of disperser solvent, pH value and salt addition were studied and optimized The method was linear in the ranges from 6.0x10-3 to 100.0 ug.mL-1 for aforementioned phenols with R2 (correlation coefficients) >= 0.9955. The DLLME procedure allowed efficient recovery of the investigated phenols ranging between 85 "A and 96 "A with a relative standard deviation (RSD) 3.2 for actual wastewater samples spiked with 10, 40 and 80 mu g center dot mL(-1) of phenols, respectively. These results show the potential of this technique for phenols monitoring in wastewater samples. Furthermore, the investigated methods are simple, reproducible, and inexpensive.