title: Evaluation of atrazine positive and false positive immunoassay detections in ground water.
abstract: False positive responses on an atrazine (6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine) immunoassay kit were investigated to explain possible causes for these occurrences. Ground water samples were evaluated with the immunoassay kit and positive responses (> 0.20 microgram L-1) were confirmed using gas chromatography/mass spectrometry (GC/MS). Non-confirming samples (false positives) were analyzed for seven additional compounds on GC. Resulting GC/MS and GC analyses showed that 70% of the false positives could be attributed to two compounds. Prometon (6-methoxy-N,N'-bis(1-methylethyl)-1,3,5-triazine-2,4-diamine) was responsible for the majority (64%) of the false positive responses The atrazine metabolite, deethylatrazine (2-chloro-4-amino-6-isopropylamino-1,3,5-triazine), was responsible for the other 6% of the false positives measured. Unattributed false positives (30%) were probably due to an overestimation of pesticide concentrations in the kit's lower detection range.
authors.affiliation: USDA-ARS Coastal Plains Soil, Water, and Plant Research Center, Florence, SC 29501, USA.
authors.forename: D W
authors.initials: DW
authors.lastname: Watts
authors.forename: J M
authors.initials: JM
authors.lastname: Novak
mesh_terms: D001280:Atrazine / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D005189:False Positive Reactions; D005618:Fresh Water / Q000032:analysis* / Q000737:chemistry; D006540:Herbicides / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D006540:Herbicides; D012989:Soil Pollutants; D001280:Atrazine