HPLC-UV Analysis of Phenol and Chlorophenols in Water After Precolumn Derivatization with 4-Fluoro-7-nitro-2,1,3-benzoxadiazole

Abstract

Chlorophenols (2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, 2,6-dichlorophenol, and 2,4,6-trichlorophenol) are present in drinking water and tap water as a result of disinfection processes employing chlorination. In this study, the levels of phenol and the above chlorophenols in water (100 µL aliquots) were simultaneously analyzed by HPLC-UV (380 nm) after precolumn derivatization with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F). Standard curves were obtained after derivatization with NBD-F in borate buffer (pH 8.5) at room temperature for 5 min. The six NBD-labeled compounds were well separated in less than 20 min. Plots were linear in the range of 0.01∼0.03 to 0.5 mg/L, with r ² value ≥0.9953, for all compounds. The lower limits of detection were 0.004 to 0.01 mg/L (signal-to-noise ratio of 3:1). The coefficients of variation were less than 5.7%. The recovery values of phenol and chlorophenols from tap water and natural mineral water spiked with the standard mixture were satisfactory. While the levels of phenol and chlorophenols in water samples tested were below the lower limit of determination, our method is expected to be useful for identifying environmental water samples that are contaminated with phenol and chlorophenols, i.e., for testing whether or not official guidelines are met.