Sundqvist B, Kamensky I, Håkansson P, Kjellberg J, Salehpour M, Widdiyasekera S, Fohlman J, Peterson P A, Roepstorff P
Biomed Mass Spectrom. 1984 May;11(5):242-57. doi: 10.1002/bms.1200110509.
Fast heavy ions, i.e. fission fragments from a 252Cf-source, have been used to desorb and ionize peptides and proteins from a sample surface. Masses of the desorbed ions have been determined by the time-of-flight technique. The mass interval of the molecules studied is 1000-14 000 u. Quasi-molecular ions of higher masses than earlier reported have been observed. The results include the detection of quasi-molecular ions of proinsulins, cytochrome-C, ribonuclease and two phospholipases. The general features of mass spectra of proteins using this ionization method are described. Emphasis is put on the discussion of metastable ion decay, neutral components, multiply charged ions, isotopic broadening, and cluster ion formation. Also the precision which can be obtained with a straight time-of-flight mass spectrometer will be discussed. Future applications of the technique are outlined.
快速重离子，即来自252Cf源的裂变碎片，已被用于从样品表面解吸并电离肽和蛋白质。已通过飞行时间技术确定了解吸离子的质量。所研究分子的质量范围为1000 - 14000 u。观察到了质量比先前报道更高的准分子离子。结果包括检测到胰岛素原、细胞色素C、核糖核酸酶和两种磷脂酶的准分子离子。描述了使用这种电离方法的蛋白质质谱的一般特征。重点讨论了亚稳离子衰变、中性成分、多电荷离子、同位素展宽和簇离子形成。还将讨论使用直型飞行时间质谱仪可获得的精度。概述了该技术的未来应用。
