Abstract: A new method for the determination of 16 biogenic amines (BAs) including dimethylamine, trimethylamine, trimethylamine oxide, octopamine (OA), dopamine (DA), tyramine (TYR), 5-hydroxytryptamine (5-HT), benzylamine, putrescine, cadaverine, histamine, agmatine, 2-phenylethylamine, tryptamine, spermidine and spermine in cold-chain fish and shrimp products was established using liquid chromatography-tandem mass spectrometry (LC-MS/MS) without derivatization. Samples were extracted by homogenizing with a solvent mixture of 1% (V/V) formic acid-80% (V/V) acetonitrile solution and degreased with n-hexane. Then, volatile ion-pairing reversed-phase chromatographic separation was carried out on a Waters XSelectTM HSS T3 column with gradient elution using a mobile phase consisting of 5 mmol/L nonafluoropentanoic acid (NFPA) solution (A) and 5 mmol/L NFPA in acetonitrile (B), and mass spectrometric detection was performed using an electrospray ionization source in the positive ion mode with multiple reaction monitoring (MRM). Dimethylamine-d6 and 1,7-diaminoheptane were used as internal standards for quantification. The results showed that all 16 BAs were well separated chromatographically and each BA exhibited good linearity in the concentration range of 10 to 1 000 ng/mL, with correlation coefficients (R2) greater than 0.995. The limits of detection (LODs) ranged from 0.15 to 1.50 mg/kg and the limits of quantification (LOQs) were in the range of 0.5–5.0 mg/kg. The average recoveries for spiked samples were between 81.15% and 109.90%, with relative standards deviations (RSDs) of less than 10%. All analytes except TRY, 5-HT, DA and OA were detected in commercial cold-chain fish and shrimp products. This method, characterized by simple sample preparation, high sensitivity, good accuracy and precision, provides valuable technical references for the highly efficient detection of BAs via underivatized LC-MS/MS, as well as for comprehensive quality evaluation of cold-chain fish and shrimp products based on BAs as markers.

Key words: biogenic amines; cold-chain fish and shrimp; volatile ion-pair; liquid chromatography-tandem mass spectrometry