Preparation of magnetic cationic Schiff base polymeric material for highly selective enrichment of avermectins from surface water and milk samples.

Herein, a magnetic cationic Schiff base polymeric material (Fe3O4@SiO2-Schiff-TAPB-DA) was fabricated simply and rapidly, which was explored as a magnetic adsorbent for magnetic solid-phase extraction (MSPE) for enriching seven avermectins insecticides in surface water and milk matrices combined with ultra-high performance liquid chromatography mass spectrometry (UPLC-MS/MS). Under the optimized pretreatment and instrumental parameters, the analytes showed good linearity in the range of 0.5-200.0 ng·mL-1 with a correlation coefficient (R2) greater than 0.9990 and high precision. The limits of detection for the analytes were 0.004-0.047 μg·L-1 for surface water sample and 0.008-0.250 μg·kg-1 for milk samples. Satisfactory recoveries of spiked target compounds were in the range of 82.25- 100.87 % for surface water sample and 72.73- 119.62 % for milk samples. The results indicated powerfully Fe3O4@SiO2-Schiff-TAPB-DA was of significant potential as an MSPE adsorbent for the detection of avermectin insecticides in surface water and milk, which provides a quick and efficient idea for enriching avermectins insecticides in complicated matrices.