Solid-phase extraction (SPE) is one of the most commonly used
sample pretreatment techniques due to its simplicity, high enrichment
factor and low consumption of organic solvent. The selection
of appropriate adsorbents will greatly benefit the analytical performance
(such as analytical sensitivity, selectivity and precision)
improvement in SPE techniques and the quest for new SPE adsorbents
has never ceased. To date, many novel adsorbents, such as
nanometer-sized materials [9,10], carbon nanotubes [11], mesoporous
materials [12], magnetic nanoparticles [13,14] have been
employed in SPE. Magnetic nanoparticles are superparamagnetic,