title: Establishing the feasibility of coupled solid-phase extraction-solid-phase derivatization for acidic herbicides.
abstract: The significance of this research is that it improves analytical methodology used for organic chemicals in aqueous solutions by establishing the feasibility of heterogeneous chemical derivatization at the liquid-solid interface (i.e., solid-phase reaction or solid-phase derivatization). A solid-phase derivatization method for determining chlorinated herbicide acids was developed. Solid-phase extraction was used to concentrate and retain analytes on sorbents for subsequent solid-phase derivatization. Background interferences were removed from the chromatograms by electronically subtracting the responses of blank, nonfortified analyses from spiked samples. Two extraction sorbents (octadecyl bonded silica and polystyrene-divinylbenzene) and two derivatizing reagents (BF3-MeOH and trimethylsilyldiazomethane) were investigated. Recovery of 13 chlorinated herbicide acids--including pentachlorophenol, dinoseb, and bentazon (having a derivatizable functional group, -OH or -NH, bonded directly to a phenyl group); dicamba, picloram, acifluorfen, 3,5-dichlorobenzoic acid, and dacthal (having a derivatizable functional group, -COOH, bonded directly to a phenyl group); and 2,4-D, 2,4,5-T, dichlorprop, 2,4,5-TP, and 2,4-DB (having a derivatizable functional group, -COOH, bonded directly to a sp3 carbon atom)--was tested. The analytical method developed was proven successful for determining acidic herbicides, except for the dacthal diacid metabolite, in aqueous samples.
authors.affiliation: Center for the Management, Utilization, and Protection of Water Resources and Department of Chemistry, Tennessee Technological University, P.O. Box 5033, Cookeville, TN 38505, USA.
authors.forename: Lan Z
authors.initials: LZ
authors.lastname: Yu
authors.forename: Martha J M
authors.initials: MJ
authors.lastname: Wells
mesh_terms: D000143:Acids / Q000737:chemistry*; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D005240:Feasibility Studies; D006540:Herbicides / Q000737:chemistry*; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry
chemical_list: D000143:Acids; D006540:Herbicides; D006843:Hydrocarbons, Chlorinated