Fig. 3From: Screening freshness of seafood by measuring trimethylamine (TMA) levels using helium-plasma ionization mass spectrometry (HePI-MS)Intensity of the m/z 60 signal for protonated TMA recorded from headspace volatiles of shrimp (a), squid (b), salmon (c), char (d), and cod (e) samples (N = 6) kept at room temperature for 96 h.Back to article page