Xia Shifei, Zhang Lan, Tong Ping, Lu Minghua, Liu Wei, Chen Guonan
Ministry of Education Key Laboratory of Analysis and Detection Technology for Food Safety (Fuzhou University), Department of Chemistry, Fuzhou University, Fuzhou, Fujian, PR China.
Electrophoresis. 2007 Sep;28(18):3268-76. doi: 10.1002/elps.200600756.
A new method for the determination of the peptide hormones of brain and intestine based on CE coupling with a DAD and ESI-MS was established. Several electrophoretic and ESI-MS parameters were investigated in detail, such as electrolyte nature and concentration, organic solvent and sheath liquid compositions, nebulization gas pressure and the ESI capillary voltage. Optimized conditions were achieved with 25 mM formic acid-ammonium formate (pH 2.9) as the optimal electrolyte, 2 mM formic acid in 80% methanol in water as the sheath liquid, and 20 kV applied voltage. Under the optimized conditions, four protonated peptides were separated by CE and selectively detected by a quadrupole mass spectrometer with a sheath flow ESI interface. LODs for the four peptides (neurotensin hexapeptide, neurotensin, cholecystokinin tetrapeptide, and pentagastrin) were in the range of 0.10-0.60 micromol/L at an S/N of 3. The RSDs (n = 8) of the method were 0.70-1.5% for migration times and 1.6-6.1% for peak areas. This method is simple, rapid, and selective compared with RIA and ELISA techniques, and has been applied to the analysis of rat hypothalamus tissue.
建立了一种基于毛细管电泳（CE）与二极管阵列检测器（DAD）和电喷雾电离质谱（ESI-MS）联用测定脑和肠道中肽类激素的新方法。详细研究了几个电泳和ESI-MS参数，如电解质性质和浓度、有机溶剂和鞘液组成、雾化气体压力和ESI毛细管电压。以25 mM甲酸-甲酸铵（pH 2.9）作为最佳电解质、2 mM甲酸于80%甲醇水溶液作为鞘液以及施加20 kV电压，实现了优化条件。在优化条件下，通过CE分离出四种质子化肽，并采用带有鞘流ESI接口的四极杆质谱仪进行选择性检测。四种肽（神经降压素六肽、神经降压素、胆囊收缩素四肽和五肽胃泌素）在信噪比为3时的检测限为0.10 - 0.60 μmol/L。该方法迁移时间的相对标准偏差（RSD，n = 8）为0.70 - 1.5%，峰面积的RSD为1.6 - 6.1%。与放射免疫分析（RIA）和酶联免疫吸附测定（ELISA）技术相比，该方法简单、快速且具有选择性，已应用于大鼠下丘脑组织的分析。
