Evaluation of the uncertainty in measuring streptomycin in milk by ELISA.

Objective The uncertainty in detecting streptomycin in milk by ELISA was evaluated.Methods The source of uncertainty of the whole determination procedure was analyzed,and the mathematical model was developed.Results The main influencing factors and the combined uncertainty were obtained.The expanded uncertainty was 1.52 ng/mL(k=2) with 7.7 ng/mL of the content of streptomycin.The major sources of uncertainty of measurement were the measuring repeatability and the reaction temperature,and the sample recovery rate.Conclusion It is necessary to control repeatability of measurement and experimental reaction conditions to make sure the testing results are accurate by ELISA.It also should ensure that the sample recovery rate could meet the requirements.