Emxmicro 6 1 p l spectrometer

The leachates were detected by EPR analysis for quantifying the possible generated EPFRs. Specifically, the obtained leachate was first transferred and placed in an I.D. quartz tube. Afterwards, the quartz tube with the leachate was inserted into the cavity of the EPR instrument for EPFRs analysis. EPR measurements were conducted with using a Bruker EMXmicro-6/1/P/L spectrometer (Karlsruhe, Germany) at room temperature (∼25 °C). In addition, ROS in the leachates was also measured by EPR coupling with spin-trapping agent, i.e., DMPO. Briefly, a volume of 2 mL of each leachate sample was taken and mixed with 500 μL DMPO solution (100 mM), 500 μL DMPO/DMSO solution (100 mM) and 500 μL TEMP solution (of 100 mM) for detecting ^•OH, O₂^•− and ¹O₂, respectively. Then, the obtained mixture was used for the measurement of EPR. The parameters of EPR measurement were based on our previous study (Zhu et al., 2019 (link)), and also provided in the supplement (SI, Table S6).