Determination of Pyrethroids in Paris polyphylla Sample by High-Performance Liquid Chromatography Using Ultrasound-Assisted Magnetic Solid-Phase Extraction

Figure 4

Effect of pH. extraction conditions: sample volume, 50.0 mL spiked with 100 ng mL⁻¹ of four pyrethroids; magnetic nanoparticles (MNPs), 60 mg; ultrasonication time, 2 min; eluent solvent, 2 mL of acetonitrile /acetic acid (9:1, v/v).