Extraction of procymidone from alkaline soils

Analysis of pesticide residues in soil samples frequently requires multi-st age processes and incurs substantial variability. There is interest, theref ore, in developing a method of extraction that are both simple (requiring f ew steps), efficient (giving high recovery) and robust (with similar effici ency for a wide range of samples). Methods that use small amounts of organi c solvents have the advantage of small amounts of waste and low laboratory hazard. Three extracting methods, solvent shaking, Supercritical Fluid Extr action (SFE) and Accelerated Solvent Extraction (ASE) were assessed for the extraction efficiency of procymidone residues in a variety of Mediterranea n alkaline soils. Overall average procymidone recoveries were 70% shaking w ith methanol, 84% with supercritical CO2 modified with methanol, and 94.6% with acetone using accelerated solvent extraction. ASE demonstrated better recovery, faster extraction, and less risk of procymidone breakdown than SF E or shaking. SFE performed equally well as ASE, but moisture and organic c ontent affected the recovery of some soil samples. Solvent shaking was not as efficient as SFE and ASE; the recovery could have been affected by the l ow spiking rare used.