Secretions from meibomian glands located within the eyelid (commonly known as meibum) are rich in nonpolar lipid classes incorporating very-long (22-30 carbons) and ultra-long (>30 carbons) acyl chains. The complex nature of the meibum lipidome and its preponderance of neutral, nonpolar lipid classes presents an analytical challenge, with typically poor chromatographic resolution, even between different lipid classes. To address this challenge, we have deployed differential mobility spectrometry (DMS)-MS to interrogate the human meibum lipidome and demonstrate near-baseline resolution of the two major nonpolar classes contained therein, namely wax esters and cholesteryl esters. Within these two lipid classes, we describe ion mobility behavior that is associated with the length of their acyl chains and location of unsaturation. This capability was exploited to profile the molecular speciation within each class and thus extend meibum lipidome coverage. Intriguingly, structure-mobility relationships in these nonpolar lipids show similar trends and inflections to those previously reported for other physicochemical properties of lipids (e.g., melting point and phase-transition temperatures). Taken together, these data demonstrate that differential ion mobility provides a powerful orthoganol separation technology for the analysis of neutral lipids in complex matrices, such as meibum, and may further provide a means to predict physicochemical properties of lipids that could assist in inferring their biological function(s).

中文翻译：

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使用差动迁移谱法对复杂的非极性脂质组中的脂质进行分析分离。

位于眼睑内的睑板腺（通常称为睑板腺）的分泌物富含包含极长（22-30 个碳）和超长（> 30 个碳）酰基链的非极性脂质类。睑脂脂质组的复杂性质及其中性、非极性脂质类别的优势提出了分析挑战，即使在不同的脂质类别之间，色谱分辨率通常较差。为了应对这一挑战，我们采用了差动迁移谱 (DMS)-MS 来检测人睑脂脂质组，并证明其中包含的两种主要非极性类别（即蜡酯和胆固醇酯）具有接近基线的分辨率。在这两个脂质类别中，我们描述了与其酰基链长度和不饱和位置相关的离子迁移行为。利用这种能力来分析每个类别内的分子形态，从而扩大睑脂脂质组的覆盖范围。有趣的是，这些非极性脂质的结构-迁移率关系显示出与之前报道的脂质其他理化性质（例如熔点和相变温度）相似的趋势和变化。总而言之，这些数据表明，微分离子淌度为分析复杂基质（例如睑脂）中的中性脂质提供了强大的原醇分离技术，并可能进一步提供一种预测脂质理化性质的方法，从而有助于推断其生物学功能（s）。