Determination of ricin by double antibody sandwich enzyme-linked immunosorbent assay

A method for the determination of ricin by double antibody sandwich enzyme-linked immunosorbent assay was developed, the experiment conditions, including ricin polyclonal antibody peridium concentration and method, ricin monoclonal antibody working concentration, second enzyme labelling antibody and developing time were optimized. The linear range of the method is 1.2 to 10.0 mu g/L. The linear equation is y = 0.05x + 0.42 and the correlation coefficent is 0.9962. The limit of detection of the method is 0.2 mu g/L. The reproducibility and specificity of the method are good enough for immune analysis and quantitative analysis. The method was applied to determine trace ricin in water, soil, milk powder and blood samples, the recoveries were from 91.7% to 104.0% for water samples, from 83.3% to 98.0% for soil samples, from 83.3% to 94.0% for milk powder samples and from 75.0% to 82.0% for blood samples. The method is simple, fast and very suitable to quickly qualitative and semi-quantitative analysis of ricin.