Investigation of indicative methods in the Netherlands: validation of several commercial ELISAs for pesticides Original Research Article

Commercially available ELISAs were evaluated and validated for application in water quality control in the Netherlands. Several pesticides were selected as target compounds based on occurrence in surface water and availability of kits. Three group-specific (triazines, cyclodienes, phenylurea herbicides) and two single-compound-specific ELISAs (isoproturon, carbendazim) were included in the study. Evaluation was performed with spiked samples by determining several parameters such as detection limit, precision, linearity, accuracy, matrix effects etc. for each kit. Validation and performance testing using surface water sampled at 10 different locations were conducted at three laboratories simultaneously. Values obtained from each laboratory were compared mutually as well as with those of conventional reference methods (HPLC-DAD, GC-MS). The results were subjected to statistical analysis. It appeared that these ELISAs were very useful for discriminating positive from negative samples; no false-negative values were found and about 10% were false-positive. Moreover, the single-compound-specific ELISA kits seem promising for quantitative analyses of pesticides in surface water.