Optimization of Solid-Phase Extraction Conditions for Perfluorooctanoic Acid in Leachate

In order to optimize the solid phase extraction (SPE) conditions of perfluorooctanoic acid (PFOA) in the raw leachate and treated leachate, the effects of activator properties, SPE cartridge, pH value, ionic strength, and eluent properties were studied through single factor experiments. The optimal results of each single factor were obtained. Considering that the concentration of PFOA in the treated leachate is lower than that of the raw leachate, the SPE conditions of the treated leachate have been further optimized. Based on the above single-factor experiment, the main influencing factors were screened out as the volume of activator, ionic strength, and volume of eluent, and the three-factor three-level response surface methodology (RSM) was optimized. The optimum SPE conditions of PFOA from treated landfill leachate were as follows: Activation of weak anion exchange(WAX) cartridge with 10 mL methanol, dosage of 600 mg KCl, 6 mL 1% ammonia methanol eluted PFOA, the theory recovery rate is over 95.67%. It has been verified that the error between the predicted value and the actual extraction recovery is small and has good repeatability.