Validation of a gas-chromatographic method for volatile amine determination in fish samples

A gas-chromatographic (GC) procedure is described for the determination of volatile amines in fish. The method includes a first step of volatile amine extraction with 0.6 N perchloric acid, followed by alkalinization with 65% (ww) KOH and a subsequent toluene extraction. Dimethylamine (DMA) and trimethylamine (TMA) were well resolved; moreover, monomethylamine (MMA) did not interfere in the determination of DMA and TMA, and can also be useful in assessing spoilage of crustaceans. The suitability of toluene as a solvent for extraction is demonstrated. Linearity, precision and recovery were satisfactory. Sensitivity limits were lower than 0.038, 0.110 and 0.167 mg N per 100 g for TMA, DMA and MMA, respectively. In addition, contents of DMA and TMA in fresh and frozen hake samples were studied.