Occurrence of triazine herbicides and metolachlor in the Niagara River and other major tributaries draining into Lake Ontario Original Research Article

Immunoassay methods for triazines and metolachlor as a screening tool were evaluated at the National Laboratory for Environmental Testing (NLET). Correlation coefficients (R2) of 0.992 for triazines and 0.999 for metolachlor were determined. The detection limits were statistically calculated to be 0.070 ppb for triazines and 0.012 ppb for metolachlor. Immunoassay results for samples from the Niagara River were compared to the conventional GC/MS method. Immunoassay results were consistently biased high. Based on immunoassay results, concentrations in Lake Ontario tributaries ranged from 5 to 1650 ng/l for triazines and 15 to 225 ng/l for metolachlor.