多支链饱和脂肪酸质谱特征及其在海洋动物中的含量分析

Analysis of Mass Spectrometry Characteristics of Multi-branched Saturated Fatty Acids and Contents in Marine Animals

采用气相色谱-质谱法对4,8,12-三甲基十三烷酸甲酯、2,6,10,14-四甲基十五烷酸甲酯和3,7,11,15-四甲基十六烷酸甲酯的断裂规律和质谱特征进行分析归纳,并对常见海洋动物中的上述3种多支链饱和脂肪酸含量进行分析。试验结果表明:依据有机质谱学规律,通过较强碎片离子间相差[-CH(CH3)-](即离子质荷比相差28)能准确分析出多支链饱和脂肪酸中甲基支链所处碳链位置,同时结合分子离子以及麦氏重排离子等特征离子能准确有效地对多支链饱和脂肪酸进行分析鉴定。对多种海洋动物分析发现,海洋动物中多支链饱和脂肪酸的含量较低,一般在0.1%以下,但皱纹盘鲍、杂色鲍等海洋贝类以及鳕鱼、南极磷虾等海洋动物对多支链饱和脂肪酸表现出不同的积累作用和组织差异性。

The fragmentation rule and mass spectrometry characteristics of 4,8,12-trimethyltridecanoic acid methyl ester,2,6,10,14-tetramethylpentadecanoic acid methyl ester,and 3,7,11,15-tetramethylhexadecanoic acid methyl ester were studied,and also the compositions of multi-branched saturated fatty acids of marine organisms were analyzed in this paper.The results indicated that the Methyl branched chain in multi-branched saturated fatty acids could be accurately located by the difference between two strong fragment ions（[-CH（CH3）-],namely the difference of 28 in mass-to-charge ratio）.Meanwhile,multi-branched saturated fatty acids could be analyzed and identified using molecular ions,McLafferty rearrangement ions and other characteristic ions.Marine animals had a low multi-branched saturated fatty acids content,which was generally far below 0.1%.However,Haliotis discus hannai Ino,Haliotis diversicolor Reeve and other marine shellfishes,codfish and Antarctic krill showed differences in the accumulation and tissues to multi-branched saturated fatty acids.