Research Article

Magnetic Solid-Phase Extraction Using Fe3O4@SiO2 Magnetic Nanoparticles Followed by UV-Vis Spectrometry for Determination of Paraquat in Plasma and Urine Samples

Figure 3

Factors affecting the extraction efficiency. The extraction efficiency (%) was determined as a function of pH (a), the amount of Fe3O4@SiO2 (b), the extraction time (c), and the sample volume (d).
(a)
(b)
(c)
(d)