Analysis of triacylglycerols and whole oils by matrix-assisted laser desorption/ionization time of flight mass spectrometry
Analysis of triacylglycerols and whole oils by matrix-assisted laser desorption/ionization time of flight mass spectrometry
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DOI：
10.1016/s1044-0305(99)00063-x
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发表时间：
1999-10-01
影响因子：
3.2
通讯作者：
Hill, HH
中科院分区：
文献类型：
--
作者：
Asbury, GR;Al-Saad, K;Hill, HH
自从基质辅助激光解吸/电离(MALDI)质谱学被引入以来，大多数研究都集中在开发用于定性测定蛋白质、多肽、碳水化合物和寡核苷酸等水溶性生物分子的分析方法。然而，本文报道了MALDI用于三酰甘油的分析，并开发了一种新的非极性分析物的样品制备方法。MALDI使三酰甘油(TAG)标准和全油混合物的快速分析成为可能。新方法提供了极好的镜头重现性，使量化成为可能。检测下限在中飞摩尔范围内，分辨率在2000左右，可以很容易地将一个双键不同的标记分开。随着相对分子质量的增加，灵敏度降低，当分析具有较大分子量范围的复杂混合物时，会导致结果的偏差。在所有情况下，在光谱中只观察到盐化分子和脂肪酸钠盐的迅速损失。根据这一信息，有可能确定甘油主干上的三种脂肪酸。在三酰甘油上进行了碰撞诱导解离，这被证明是有用的额外结构信息，包括脂肪酸成分的确证。用MALDI法准确测定了标准橄榄油中标签的百分含量。最后，利用MALDI检测了老化洋葱种子和新鲜洋葱种子中脂肪成分的差异，显示了该技术在观察种子中脂肪成分变化方面的潜力。(J am Soc MS Spectrm 1999，10,983-991)(C)1999美国质谱学学会。
Since the introduction of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry the majority of research has focused on developing analytical methods for the qualitative determination of water soluble biomolecules such as proteins, peptides, carbohydrates, and oligonucleotides. This paper, however, reports the use of MALDI for the analysis of triacylglycerols and develops a new sample preparation method for nonpolar analytes. MALDI enables the rapid analyses of triacylglycerol (TAG) standards and mixtures of whole oils. The new method provides excellent shot to shot reproducibility, making quantification possible. Detection limits were in the mid femtomole range and the resolution was around 2000 which easily separated TAGs differing by one double bond. Sensitivity decreased with increasing molecular weight, causing biased results when analyzing complex mixtures with a significant range of molecular weight. In all cases only sodiated molecules and prompt losses of a fatty acid sodium salt were observed in the spectra. From this information it was possible to identify the three fatty acids on the glycerol backbone. Collision-induced dissociation was carried out on a triacylglycerol which proved to be useful for additional structural information, including the corroboration of the fatty acid components. With MALDI the percent compositions of TAGs in a standard olive oil was accurately determined. Finally, MALDI was used to examine the differences in lipid components between aged and fresh onion seeds, showing the potential of the technique for observing changes in lipid components in seeds. (J Am Soc Mass Spectrom 1999, 10, 983-991) (C) 1999 American Society for Mass Spectrometry.