Abstract:This study established a non-suppressed ion chromatography method capable of simultaneously measuring dimethylamine，trimethylamine，and trimethylamine N-oxide. The sample was extracted with a 1%trichloroacetic acid solution，purified with chloroform，and subjected to ultrasonic-assisted extraction and high-speed refrigerated centrifugation to remove protein interference. Separation was performed on a Dionex Ionpac CS 17 cation exchange column using 3.08 mmol/L methanesulfonic acid as the mobile phase at a flow rate of 0.8 mL/min，achieving complete separation of the three target amines within 15 min. The limits of quantification for dimethylamine，trimethylamine，and trimethylamine N-oxide were 0.17，0.21，and0.25 mg/g，respectively. Furthermore，combined with liquid chromatography-mass spectrometry，a multi-target detection and analysis system suitable for N-nitrosodimethylamine and its precursors in aquatic products and dried products was established. Based on this detection system，the contents of trimethylamine N-oxide，dimethylamine，trimethylamine，and N-nitrosodimethylamine in cod fillets during processing were systematically monitored，and the variation patterns between the precursors and N-nitrosodimethylamine were explored. This provides a methodological basis and theoretical support for elucidating the formation mechanism and key control points of N-nitrosodimethylamine during the processing of dried aquatic products.