Fast Derivatization Followed by Gas Chromatography-Mass Spectrometry for Simultaneous Detection of Melamine, Ammeline, Ammelide, and Cyanuric Acid in Fish and Shrimp

A sensitive and reliable method was proposed for the simultaneous detection of melamine, ammeline, ammelide, and cyanuric acid in fish and shrimp by gas chromatography-mass spectrometry after fast derivatization. The analytes were derivatized using a 99:1 mixture of N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and trimethylchlorosilane (TMCS) under microwave irradiation for 2 min with a power of 700 W, followed by determination with gas chromatography-mass spectrometry in selected ion monitoring mode. Conditions for extraction and derivatization of melamine and related compounds were investigated and optimized. Under the optimal experimental conditions, the limits of detection (LODs, S/N = 3) for melamine, ammeline, ammelide, and cyanuric acid were 0.006, 0.012, 0.013, and 0.010 mg kg(-1), respectively. The developed method was successfully applied to determine melamine and related compounds in fish and shrimp samples, and the spike recoveries were 82.5-103.1 % with relative standard deviations (RSDs) (n = 3) of 0.6-4.1 %.