Malachite Green Laboratory Methods

 

Amendment:
Application of Laboratory Information Bulletins 4333 and 4334 for the Determination of
Leucomalachite Green and Malachite Green Residues in Catfish, Basa, Tilapia, Trout, and Shrimp

A modified extraction was validated by LC-VIS and LC-MSⁿ for LMG and MG residues in catfish, basa, tilapia, trout, and shrimp, and was verified in eel. To achieve high residue recoveries in these species, the following changes should be made to the salmon extraction detailed in LIB 4334 (page 7):

1. Increase the quantity of alumina used in the initial extraction from 6 g to 10 g.
2. In the liquid-liquid extraction step, let phases separate for a maximum of 10 minutes (salmon method states 15 minutes minimum).