Fabrication of a novel azamacrocycle-based adsorbent for solid-phase extraction of organophosphorus pesticides in tea drinks

A novel azamacrocycle-based adsorbent for solid-phase extraction was synthesized by coupling a 26-membered aromatic-aliphatic-mixed azamacrocycle to 3-chloropropyltrimethoxylsilane-modified silica. The obtained material was characterized by elemental analysis and fourier transform-infrared spectroscopy. The adsorbent showed excellent performance for extracting organophosphorus pesticides (fenitrothion, parathion, fenthion and phoxim), which may be due to multiple interactions between the adsorbent and organophosphorus pesticides, including π–π, hydrophobic, dipole-dipole, charge-transfer, hydrogen-bonding and inclusion interactions. The main parameters that affected the extraction efficiency were investigated, including the amount of adsorbent, the volume and flow rate of the sample solution, the elution solvent and the ionic strength. This azamacrocycle-based extraction technique was further combined with high-performance liquid chromatography to measure trace organophosphorus pesticides in tea drinks. The method showed good linearity (5–500 ng/mL), low limit of detection (0.10 ng/mL), and high recoveries from spiked samples (90.4%–113.5%) were obtained with low relative standard deviation (0.6%–8.9%, n  = 3). The azamacrocycle-based adsorbent showed good extraction performance and offered a promising application in the extraction of organophosphorus pesticides from complicated tea drinks.