Magnetic partially carbonized cellulose nanocrystal-based magnetic solid phase extraction for the analysis of triazine and triazole pesticides in water.

Magnetic partially carbonized cellulose nanocrystals (MPC-CNC) were obtained by sulfuric acid treatment of microcrystalline cellulose (MCC) and then loaded with magnetic FeO nanoparticles. The material is shown to be a viable material for magnetic solid phase extraction of triazine and triazole pesticides from water. The pesticides (specifically: simazine, ametryn, prometryn, terbutryn, atrazine, triadimenol, epoxiconazole, myclobutanil, triadimefon and tebuconazole) were quantified by ultra HPLC in tandem with a triple quadrupole mass spectrometry (UHPLC-MS/MS). The effects of NaCl concentration, amount of adsorbent, vortex time, sample volume and pH value on extraction efficiency were optimized by Plackett-Burman design and Box-Behnken design methods. Under the optimal conditions, the method shows the following figures of merit: (a) Linear responses in the range from 0.02-10 μg L; (b) detection limits between 2.2 to 6.1 ng L (for S/N = 3); (c) recoveries from spiked samples of 73.7-117.1% with relative standard deviations (RSDs) of 2.0-15.7%; and (d) an enrichment factor of 75. The method was successfully applied to the determination of the pesticides in five environmental water samples. Graphical abstract Schematic representation of the process of magnetic solid phase extracting pesticides in water using MPC-CNC. MCC-microcrystalline cellulose; PC-CNC- partially carbonized cellulose nanocrystals; MPC-CNC-magnetic partially carbonized cellulose nanocrystals.