Oosterkamp A J, Gelpí E, Abian J
Department of Medical Bioanalysis, IIBB-CSIC, Barcelona, Spain.
J Mass Spectrom. 1998 Oct;33(10):976-83. doi: 10.1002/(SICI)1096-9888(1998100)33:10<976::AID-JMS710>3.0.CO;2-7.
Many endogenous peptides are circulating in bodily fluids at the low pmol l-1 range, placing high demands on the bioanalytical procedure. In order to analyze these minute concentrations in complex matrices, a miniaturized liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) bioanalysis method was developed using custom-made nanoLC columns (75 microns i.d.) and a micro-electrospray interface (micro ESI). To be able to analyze large sample volumes in order to cope with low biological analyte concentrations, the nanoLC/ESI-MS method was coupled to an on-line preconcentration (PC) system based on a strong anion-exchange material. This method was used to analyze endothelin peptides (ETs) in complex matrices, which are potent vasoconstrictors of M(r) approximately 2500 Da. The ET isoforms could be simultaneously analyzed with detection limits down to 30 pmol l-1 in cell supernatants (1.5 fmol on column). The method was linear from 50 to 2000 pmol l-1 with correlation coefficients of 0.99 for two of the three endothelin isoforms. Several other parameters, such as matrix effects and recovery, were also investigated.
许多内源性肽在体液中的浓度处于低皮摩尔每升（pmol l⁻¹）范围，这对生物分析程序提出了很高的要求。为了在复杂基质中分析这些微量浓度，开发了一种小型化液相色谱/电喷雾电离质谱（LC/ESI-MS）生物分析方法，该方法使用定制的纳米液相色谱柱（内径75微米）和微电喷雾接口（微ESI）。为了能够分析大量样品以应对低浓度的生物分析物，纳米LC/ESI-MS方法与基于强阴离子交换材料的在线预浓缩（PC）系统联用。该方法用于分析复杂基质中的内皮素肽（ETs），它们是分子量约为2500道尔顿（Da）的强效血管收缩剂。内皮素异构体能够同时进行分析，在细胞上清液中的检测限低至30 pmol l⁻¹（柱上1.5飞摩尔）。该方法在50至2000 pmol l⁻¹范围内呈线性，三种内皮素异构体中的两种的相关系数为0.99。还研究了其他几个参数，如基质效应和回收率。
