Rapid Quantitative Determination of Trimethylamine using Steam Distillation.

A simple, rapid and inexpensive method is proposed for determination of trimethylamine (TMA) in fish muscle. This procedure includes a deproteinization step with trichloroacetic acid (TCA) followed by blocking of primary and secondary amines using formaldehyde at alkaline pH and finally steam distillation of TMA. No statistically significant differences were found between this new optimized procedure and either the Conway microdiffusion method or the colorimetric method. Using the technique proposed here it is possible to assay both the total volatile basic nitrogen (TVBN) and the TMA in less than 30 min.