Visual Cognition Laboratory, Department of Medicine, Chemin du Musee 5, University of Fribourg, Fribourg CH-1700, Switzerland.
J Chromatogr A. 2012 Jun 8;1241:46-51. doi: 10.1016/j.chroma.2012.04.002. Epub 2012 Apr 9.
Endogenous quaternary ammonium compounds are involved in various physiological processes in the central nervous system. In the present study, eleven quaternary ammonium compounds, including acetylcholine, choline, carnitine, acetylcarnitine and seven other acylcarnitines of low polarity, were analyzed from brain extracts using a two dimension capillary liquid chromatography-Fourier transform mass spectrometry method. To deal with their large difference in hydrophobicities, tandem coupling between reversed phase and hydrophilic interaction chromatography columns was used to separate all the targeted quaternary ammonium compounds. Using high accuracy mass spectrometry in selected ion monitoring mode, all the compounds could be detected from each brain sample with high selectivity. The developed method was applied for the relative quantification of these quaternary ammonium compounds in three different brain regions of tree shrews: prefrontal cortex, striatum, and hippocampus. The comparative analysis showed that quaternary ammonium compounds were differentially distributed across the three brain areas. The analytical method proved to be highly sensitive and reliable for simultaneous determination of all the targeted analytes from brain samples.
内源性季铵化合物参与中枢神经系统的各种生理过程。在本研究中，采用二维毛细管液相色谱-傅里叶变换质谱法，从脑提取物中分析了 11 种季铵化合物，包括乙酰胆碱、胆碱、肉碱、乙酰肉碱和 7 种其他低极性酰基肉碱。为了处理它们在疏水性上的巨大差异，采用反相和亲水相互作用色谱柱串联耦合来分离所有目标季铵化合物。使用选择离子监测模式的高精度质谱法，从每个脑组织样本中都可以高度选择性地检测到所有化合物。所开发的方法用于定量测定树鼩三个不同脑区（前额叶皮层、纹状体和海马体）中的这些季铵化合物。比较分析表明，季铵化合物在三个脑区的分布存在差异。该分析方法对于从脑组织样本中同时测定所有目标分析物具有高度的灵敏度和可靠性。
