Fluorescence Detection of Perfluorooctanoic Acid by High Performance Liquid Chromatography with Pre-Column Derivatization

The extensive use of perfluorooctanoic acid (PFOA) has raised significant concerns about its environmental pollution. However, existing PFOA detection methods are often applied with high equipment and operation costs. This study developed a high-performance liquid chromatography-fluorescence detection method with pre-column derivatization for PFOA determination. This method was applied to the detection of PFOA in the effluent from disk-tubular reverse osmosis (DTRO) membrane treatment of leachate at a waste incineration plant. The chromatographic and derivatization conditions of the method were systematically optimized. PFOA concentrations were indirectly measured through the fluorescence peak area of its derivative with 3-bromoacetyl coumarin. The optimized method operates under the following conditions: a C18 column, a mobile phase consisting of acetonitrile and water (60 : 40, v/v) at 30°C, and fluorescence detection at an excitation wavelength of 305 nm and an emission wavelength of 420 nm. Derivatization was conducted at 70°C using 5.00 mg/mL 3-bromoacetyl coumarin in acetone, with 50 mg of tetrabutylammonium bromide as a catalyst for 150 min. The method has linear ranges of 0.01–0.10 and 0.10–1.00 mg/L, with limits of detection and quantification of 0.0021 and 0.0063 mg/L, respectively. Recoveries ranged from 86.21 to 95.81%, with a relative standard deviation (RSD) below 5%. Additionally, a spiked PFOA concentration of 0.01 mg/L in DTRO-treated leachate effluent following solid-phase extraction was successfully detected with an RSD below 5% using this method.