Synthesis and application of a novel solid-phase extraction adsorbent for multiresidue analysis of insecticides in water.

A new solid-phase adsorbent was synthesized for the simultaneous enrichment of multiple classes of trace insecticides (neonicotinoids, organophosphates, fiproles, and organochlorines) in water. The adsorbent was spherical with a diameter, surface area, average pore volume, and pore size of approximately 5 μm, 341 m2 /g, 0.092 m3 /g, and 2.22 nm, respectively. Extraction conditions were optimized, including water pH and the type and volume of the rinsing and eluting solvents. After extraction, target insecticides were analyzed by gas chromatography with mass spectrometry and high-performance liquid chromatography with tandem mass spectrometry. The recovery of neonicotinoids ranged from 63.0 to 124%, except for clothianidin (40.1-52.9%). Recoveries of organophosphates, fiproles, and organochlorines were in the ranges of 37.0-102, 64.0-101, and 42.0-69.3%, respectively. Relative standard deviations were <20% except for profenofos (5.1-30%) and method detection limits were 1.8-12.7 ng/L, suggesting that the precision and accuracy of the developed method were viable. At environmentally relevant concentrations, the new adsorbent achieved comparable recoveries of target insecticides to hydrophilic-lipophilic balance adsorbent while providing an additional advantage by further reducing matrix effects. Field water samples from the Pearl River in Guangzhou, China were analyzed, and the frequent detection of neonicotinoids raises concerns about their aquatic risk.