The identification of lipids in biological samples is gaining importance. The advent of mass spectrometry-based lipidomics accelerated the field allowing nowadays for identification and quantification of complete lipidomes. However, due to solubility difficulties and varying properties of different lipid classes, sample preparation for lipidomics is still an issue. Of the many lipid classes, phospholipids are the major components of biological membranes. In solution, they spontaneously form lipid vesicles of various structures such as liposomes. They are therefore often used as membrane mimics when studying biological membranes and membrane proteins. Here, we present a novel sample preparation strategy for shotgun lipidomics employing liposomes prepared from lipid standards or lipid mixtures allowing the analysis of phospholipids directly from lipid bilayers. We validated our strategy for lipid identification by tandem mass spectrometry in positive or negative ion mode using different phospholipid species from various classes. We further tested our strategy for relative quantification by mixing different ratios of phospholipid species as well as determining the distribution of lipid species in a natural lipid extract.

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生物样品中脂质的鉴定正变得越来越重要。基于质谱的脂质组学的出现促进了该领域的发展，从而使得如今可以鉴定和定量完整的脂质组。但是，由于溶解性困难和不同脂质类别的不同特性，脂质组学的样品制备仍然是一个问题。在许多脂质类别中，磷脂是生物膜的主要成分。在溶液中，它们自发形成各种结构的脂质囊泡，例如脂质体。因此，在研究生物膜和膜蛋白时，它们通常用作膜模拟物。这里，我们为shot弹枪脂质组学提供了一种新的样品制备策略，该策略采用了从脂质标准品或脂质混合物制备的脂质体，可直接从脂质双层中分析磷脂。我们使用不同类别的不同磷脂种类，以正离子或负离子模式验证了通过串联质谱进行脂质鉴定的策略。我们通过混合不同比例的磷脂种类以及确定天然脂类提取物中脂类的分布，进一步测试了相对定量策略。

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