Kernels or nuts infected with A. flavus may be scattered throughout a lot, so the sampling design is critical to reduce misclassification of lots. While testing methods vary slightly, results can be impacted much more by the way the sample is taken and the size of that sample.
To ensure that a test shows the accurate concentration of aflatoxin, proper sampling procedure, sample size and sample preparation is more important than the type of test that is used.
Previous research in groundnut has shown that roughly 80% of variance in test result is associated with sample size, 15% with sample preparation and 5% with test method.