Because of the suppression of 2' , 6'-dihydroxyacetophenone (DHAP) to the combination of peptide with alkali metal ion and the advanced ability of 2,5-dihydroxybenzoic acid (DHB) to ionize peptide in MALDI-MS, it is illustrated in this work that the best MALDI-FT/ICRMS is obtained when matrix is composed of 10 μmol/L DHB and 15μmol/L DHAP. The scanning electron microscope pictures of matrix with different compositions show that the crystal of matrix composed of 8 μmol/L DHB and 3 μmol/L DHAP is in a dense stratiform state that is quite different from crystal of matrix with other proportion of DHB and DHAP. It is also demonstrated that thin-layer method is the best peptide preparation method with matrix composed of 8 μmol/L DHB and 3 μmol/L DHAP among dry-droplet and sandwich method.%通过比较两种极性差异较大的基质2,5-二羟基苯甲酸( DHB)和2’,6 '-二羟基苯乙酮(DHAP)按不同比例混合时,AngiotensinⅡ的基质辅助激光解析电离-傅立叶变换离子回旋共振质谱(MALDI-FT/ICRMS)谱图的不同,并结合基质-AngiotensinⅡ在不同结晶方式下的共结晶和基质晶体的扫描电镜照片,发现基质为10 μmol/L DHB和15μmol/L DHAP以体积比4∶1组成的混合物时,基质结晶为致密的层状结构,而以薄层法与Angiotensin Ⅱ生成的共结晶,Angiotensin Ⅱ在基质晶体上面形成分散的柱状小晶体,此时得到的MALDIFT/ICRMS质谱图优于干滴法.
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