Evaluation of an enzyme-linked immunosorbent assay (ELISA) for quantifying DDAC in industrial treating solutions

An enzyme-linked immunosorbent assay (ELISA), based on polyclonal antibodies, was used to quantify didecyldimethylammonium chloride (DDAC) in industrial antisapstain treating solutions. The initial ELISA validation included: cross-reactivity with similar analytes, interference with non-related compounds, percentage of false negative and false positive determinations, and comparison of the immunoassay data with the data from titration and HPLC methods. ELISA and the titration method gave comparable results. However, higher DDAC values were obtained for industrial treating solutions measured by ELISA than by HPLC. Immunoassays may be a potential analytical tool for the quality control program of DDAC type antisapstain formulations, if specificity could be improved.