顶空气相色谱-质谱法测定动物源性食品中三甲胺

Determination of trimethylamine in animal derived food by HS-GC-MS

目的建立动物源性食品中三甲胺的顶空气相色谱-质谱法的检测。方法样品经5%三氯乙酸溶液提取后,在提取液加入50%Na OH溶液,在40℃下平衡40 min,顶空进样。选择强极性色谱柱,初始柱温为40℃,保持3 min,以30℃/min升至220℃,保持1 min,进样口温度为220℃。选择响应值较高的3个离子m/z 58、m/z 59和m/z 42作为定性离子,以丰度最高的离子m/z 58为定量离子,选择离子监测模式进行检测,以外标法定量。结果三甲胺的浓度为1.0 mg/L^40.0 mg/L时,线性关系良好,线性回归方程为y=344 113x-228 785,相关系数(r)为0.999 5。在5.44 mg/kg、17.2 mg/kg和25.0 mg/kg 3个添加水平下,样品的回收率为94.67%~106.60%。该方法的相对标准偏差(RSD)为2.76%~4.08%,检出限为1.0 mg/kg。结论该方法操作简单、准确度和精密度高,能满足动物源性食品中三甲胺含量的测定。

Objective A headspace gas chromatography mass spectrometry（ HS- GC- MS） method was developed for determination of trimethylamine（ TMA） in animal derived food. Methods The samples were extracted with 5% trichloroacetic acid,in the extraction solution,50% Na OH solution was added,and balanced at 40 ℃ for 40 min,and finally the samples were added into the headspace. The strong polarity column was chose as the chromatographic column; The chromatography column temperature program were following： initial temperature was 40 ℃,keeping 3 min,raised to 220 ℃ by 30 ℃ / min,keeping 1 min. Injection temperature was 220 ℃; The higher response value of m / z 58,m / z 59 and m / z 42 three ions were selected as qualitative ions,and the highest abundance of m / z 58 was selected as quantitative ion; Selective ion monitoring mode was used to detect,and quantitated by external standard method. Results The method showed a good linearity in the range of1. 0 mg / L- 40. 0 mg / L,the linear regression equation was y = 344 113x- 228 785 and the correlation coefficient was 0. 999 5.At 3 mg / kg,17. 2 mg / kg and 25 mg / kg of the three additive level,the recovery rate of the sample was 94. 67%- 106. 60%.The relative standard deviation（ RSD） of this method was 2. 76%- 4. 08%. The limit of detection was 1. 0 mg / kg. Conclusion This method is convenient,accurate and precisive,and could be used for quantification of trimethylamine in animal derived food.