Development and validation of a method for the simultaneous determination and confirmation of melamine and cyanuric acid in fish kidney by LC/MS/MS

Abstract

A method was validated to simultaneously determine and confirm melamine and cyanuric acid in fish kidneys by LC/MS/MS. This method is capable of detecting both compounds in a single procedure, whether present as free compounds or bound together as the melamine-cyanurate complex in both channel catfish (Ictalurus punctatus) and rainbow trout (Oncorhynchus mykiss) kidneys. Residues are extracted with no additional cleanup and analyzed by LC/MS/MS using external standard calibration. The method is capable of quantifying residues over a range of 0.4 to 50 μg/g. For both compounds and species of fish tested, the LOD is estimated to be 0.1 μg/g and the LOQ 0.4 μg/g. Recoveries and RSDs are 83 to 101% and 2 to 8%, respectively. In catfish, matrix effects are higher for melamine than cyanuric acid. In rainbow trout, similar matrix effects are found for both compounds.