The minimum amount of α-amanitin that was identified with 100% agreement by testers was 2 μg. For the second part, there was 100% agreement that psilocin gives a positive Meixner test (100% false positive) and a 35% recognition rate of the 5-substituted tryptamine compounds as a positive Meixner test. There was no statistical difference between the interpretation of α-amanitin and psilocin, suggesting the test is unable to differentiate between them.
Conclusion
Although the Meixner test has a good detection limit for toxic amounts of α-amanitin, a positive Meixner reaction does not adequately distinguish between α-amanitin and other mushroom indoles.