title: Cost analysis of ELISA, solid-phase extraction, and solid-phase microextraction for the monitoring of pesticides in water.
abstract: The implementation of a pesticide water monitoring program in South Africa is limited by a lack of financial and analytical resources. A cost analysis of three analytical methods, enzyme-linked immunosorbent assays (ELISA), solid-phase microextraction (SPME), and traditional solid-phase extraction methods (SPE), was conducted. The cost analysis assumed a hypothetical scenario in terms of the sampling area (a grape farming rural region in the Western Cape province of South Africa), sample collection (weekly grab samples collected from eight sites by an environmental health officer in a nearby town), transport of samples (via courier), and analysis (endosulfan and chlorpyrifos analysis conducted by a local higher educational institution laboratory in Cape Town). The cost per sample for the three analytical methods was determined by estimating the annual capital costs, including building and equipment, and recurrent costs, including transport, personnel, supplies, and building operating costs. At the optimal utility of resources, SPME had the lowest cost per sample (US $37), followed by SPE (US $48.50) and ELISA (US $60). Recurrent costs formed the bulk of the costs of all three methods (91-97%). The cost of supplies was particularly high for ELISA (US $34 per sample). The cost per sample estimated for all three methods is substantially lower than those quoted by other laboratories in South Africa. The low cost of SPME is particularly important because of the sensitivity and reliability of this method and the faster output compared to SPE, and SPME is recommended for the long-term monitoring of pesticide pollution.
authors.affiliation: Occupational and Environmental Health Research Unit, School of Public Health and Family Medicine, Faculty of Health Sciences, University of Cape Town, Anzio Road, Observatory, 7925, Cape Town, South Africa. aqiel@cormack.uct.ac.za
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Dalvie
authors.forename: E
authors.initials: E
authors.lastname: Sinanovic
authors.forename: Leslie
authors.initials: L
authors.lastname: London
authors.forename: Eugene
authors.initials: E
authors.lastname: Cairncross
authors.forename: A
authors.initials: A
authors.lastname: Solomon
authors.forename: H
authors.initials: H
authors.lastname: Adam
mesh_terms: D004390:Chlorpyrifos / Q000032:analysis; D003365:Costs and Cost Analysis; D004726:Endosulfan / Q000032:analysis; D004784:Environmental Monitoring / Q000191:economics* / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay / Q000191:economics*; D006801:Humans; D010575:Pesticides / Q000032:analysis*; D012424:Rural Population; D013019:South Africa; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000191:economics
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical; D004390:Chlorpyrifos; D004726:Endosulfan