Byrdwell W C
FQS, NCAUR, ARS, USDA, Peoria, Illinois 61604, USA.
Rapid Commun Mass Spectrom. 1998;12(5):256-72. doi: 10.1002/(SICI)1097-0231(19980314)12:5<256::AID-RCM149>3.0.CO;2-8.
Analysis of phospholipids was performed using a liquid chromatographic separation with two mass spectrometers in parallel providing electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) data simultaneously from a triple quadrupole instrument and a single quadrupole instrument, respectively. The output from UV-Vis and evaporative light scattering detectors were also acquired by the two mass spectrometers, respectively, for four detectors overall. This arrangement was used to identify and calculate area percents for molecular species of dihydrosphingomyelin (DHS) and sphingomyelin (SPM) in commercially available bovine brain SPM, in human plasma extract and in porcine lens extract. Molecular species of phosphatidylethanolamine and its plasmalogen, and phosphatidylcholine and its plasmalogen were identified and semi-quantitative analysis performed. Commercially available bovine brain SPM was found to contain 11.5% DHS and 88.5% SPM. The only DHS molecular species identified in human plasma was 16:0-DHS, at or below 1% of the sphingolipid content. Porcine lens membranes were found to contain 14.4% DHS and 85.6% SPM. Other findings reported here include: (1) phospholipids were found to undergo dimerization in the electrospray source, giving masses representing combinations of species present. (2) Triacylglycerols gave usable mass spectra under electrospray ionization conditions, as well as under APCI-MS conditions. (3) Triacylglycerols gave ammonium adducts as base peaks in their APCI mass spectra, which reduced fragmentation and increased the proportions of molecular ions. (4) Mass spectra were obtained for phospholipids which underwent both protonation and sodium adduct formation in different chromatographic runs.
磷脂分析采用液相色谱分离法，同时使用两台质谱仪，分别从三重四极杆仪器和单四极杆仪器并行提供电喷雾电离（ESI）和大气压化学电离（APCI）数据。两台质谱仪还分别采集了紫外可见和蒸发光散射检测器的输出信号，总共四个检测器。这种配置用于鉴定和计算市售牛脑鞘磷脂（SPM）、人血浆提取物和猪晶状体提取物中二氢鞘磷脂（DHS）和鞘磷脂（SPM）分子种类的面积百分比。鉴定了磷脂酰乙醇胺及其缩醛磷脂、磷脂酰胆碱及其缩醛磷脂的分子种类并进行了半定量分析。发现市售牛脑SPM含有11.5%的DHS和88.5%的SPM。在人血浆中鉴定出的唯一DHS分子种类是16:0-DHS，其含量占鞘脂含量的1%或以下。发现猪晶状体膜含有14.4%的DHS和85.6%的SPM。这里报告的其他发现包括：（1）发现磷脂在电喷雾源中发生二聚化，产生代表存在的物种组合的质量。（2）三酰甘油在电喷雾电离条件下以及在APCI-MS条件下给出可用的质谱。（3）三酰甘油在其APCI质谱中以铵加合物作为基峰，这减少了碎片化并增加了分子离子的比例。（4）在不同的色谱运行中获得了既发生质子化又形成钠加合物的磷脂的质谱。
