A Simple and Straightforward Procedure for Monitoring Phenol Compounds in Waters by Using UV Solid Phase Transduction Integrated in a Continuous Flow System

摘要

A novel and sensitive flow-through method with solid phase UV spectrophotometric transduction is proposed for the direct determination of phenols: phenol, 1-naphthol, 2-naphthol, 3,4-dimethylphenol and 2,4-dichlorophenol were used as test phenol compounds. The device consists of a monochannel system using Sephadex QAE A-25 resin as packing material of the detection microzone placed inside a flow-through cell on which phenols are temporarily retained. Intrinsic absorbances are monitored at 237 nm for phenol, 242 nm for 2-naphthol and 3,4-dimethylphenol, and 247 nm for 1-naphthol and 2,4-dichlorophenol. The sample is transported by a alkaline carrier solution which acts as desorbing the solution itself. The determination of phenols was carried out for 40 and 600 µL of sample volume. The sensitivity is higher by a factor of 10 than that provided by a conventional flow injection analysis method. The detection limits were found to be close to 1 ng mL−1 in some cases (using 600 µL of sample volume). The relative standard deviations (n=10) ranged between 1.5 and 3.2% (40 µL) and 1.1 and 2.2% (600 µL). The proposed method has shown good results in its application to waters, making this method suitable for phenol monitoring.