Determination of phenols in water samples using simultaneous derivatization and dispersive liquid- liquid microextraction followed by gas chromatography

A simple,rapid and sensitive derivatization and microextraction technique for the determination of Phenols in water samples was developed using simultaneous derivatization and dispersive liquid- liquid microextraction followed by gas chromatography- flame ionization detection( GC- FID). In this method,800 μL acetic anhydride( derivatization agent) was injected rapidly into 5 m L water samples( p H = 7.00) in a test tube with conical bottom and derivatized 30 min under the temperature of 50 ℃.Then,200 μL dichoromethane( extraction solvent) and 10 μL methanol( disperser solvent) was injected into the solution and the mixture was gently shaken.After centrifugation of the cloudy solution,the derivatized analytes in the sedimented phase were determined by GC- FID. Under optimized conditions,the approach was applied to the determination of Phenols in water samples with a linearity range of 0.02~4.00 μg / m L. Correspondingly,the determination limit at an S / N of 3 were 1.98 μg / L.The recoveries of real samples at different spiked levels of Phenols ranged from 59.6% to 119.2% and the relative standard deviations less than 6.90%.