Abstract: The GUM method is a commonly used way for evaluating measurement uncertainty (MU) in the field of products detection,whereas the approach has some limitations such as the hypothesis of normal distribution in output quantity. To provide a better and more suitable method for the estimating MU of genetically modified organism (GMO) detection,the Monte Carlo method (MCM) was employed to evaluate the MU of GM corn DAS-4-40278-9 in mixed sample. The results showed that the relative content of the GM corn DAS-4-40278-9 (C) was 1% with a small MU of 3.07×10^-4;the C value fell in a 95% coverage interval of 0.94%-1.06% indicating a high detection quality. In addition,the probability density distribution of the C was presented in a normal distribution,which was consistent with the assumption mentioned above in GUM method. Because MCM can avoid the limitation in traditional GUM method,MCM should be adopted in the evaluation of MU of GMO detection.

Key words: genetically modified corn, DAS-4-40278-9, propagation of probability distribution, measurement uncertainty