Scientific Publications by FDA Staff

Food Chem Toxicol 2012 Oct;50(10):3426-32

Depletion of melamine and cyanuric acid in serum from catfish Ictalurus punctatus and rainbow trout Onchorhynchus mykiss.

Stine CB, Nochetto CB, Evans ER, Gieseker CM, Mayer TD, Hasbrouck NR, Reimschuessel R

Melamine and its triazine analogs, such as cyanuric acid, have been used to artificially inflate protein content both in animal feed ingredients, as well as in milk products produced for human consumption. We report here a LC-MS/MS method to quantify and confirm melamine and cyanuric acid in serum from channel catfish and rainbow trout with a limit of quantification of 0.8mug/mL. The method was applied to serum samples from a residue depletion study in which fish were given a single oral dose of 20mg/kg body weight melamine, cyanuric acid, or both compounds together. Samples were taken at 1, 3, 7, 14, and 28days (an additional 42day was added for trout). When given alone or in combination with cyanuric acid, melamine residues were highest on day 1 in both catfish and trout. Cyanuric acid was only quantifiable at day 1 in trout when given alone, and not at all in catfish. The serum half life of melamine in catfish was 1.50-1.62days and 3.09-3.67days in trout. This work highlights the differences of depletion kinetics in fish, which can be measured in days, as compared to the depletion in mammals, measured in hours.