Mixed-level orthogonal array design for the optimization of solid-phase extraction of some pesticides from surface water

An orthogonal array design (OAD), OA(32)(4(1)X2(28)), was employed as a che mometric method for the optimization of the solid-phase extraction (SPE) of atrazine, diazinon, ametryn and fenthion in surface water. Seven parameter s: the type of eluting solvent, type of sorbent, flow-rate of eluting solve nt, sample pH, sample volume, elution volume, addition of modifier and how- rate of water sample were studied and optimized by a mixed-level OAD. The e ffects of these factors and some two-variable interactions on the recovery of the pesticides were quantitatively evaluated by the analysis of variance and percentage contribution techniques. The final optimized condition was employed for the SPE of selected micro-organic pollutants from Karoun river water, south of Iran. Atrazine and ametryn were tentatively identified and determined at the 0.7 and 0.9 mu g l(-1) level, respectively. (C) 2000 Els evier Science B.V. All rights reserved.