GAS-PHASE CATIONIZATION AND PROTONATION OF NEUTRALS GENERATED BY MATRIX-ASSISTED LASER DESORPTION

被引：97

作者：

WANG, BH ^{[1
]}

DREISEWERD, K ^{[1
]}

BAHR, U ^{[1
]}

KARAS, M ^{[1
]}

HILLENKAMP, F ^{[1
]}

机构：

[1] UNIV MUNSTER, INST MED PHYS & BIOPHYS, MUNSTER, GERMANY

来源：

JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY | 1993年 / 4卷 / 05期

关键词：

D O I：

10.1016/1044-0305(93)85004-H

中图分类号：

Q5 [生物化学];

学科分类号：

071010 ; 081704 ;

摘要：

The ionization mechanisms involved in matrix-assisted ultraviolet laser desorption/ionization (MALDI) were studied with a time-of-flight mass spectrometer. When protonated or cationized quasimolecular ions generated by MALDI are not extracted promptly, their abundance is a function of the delay time between laser irradiation and ion extraction, maximizing at an optimum delay time (DTM) of a few hundred nanoseconds. The ion abundance at DTM exceeds that of prompt extraction by a factor of 2 or more. Increasing the cation density near the sample surface reduces the DTM, whereas increasing the desorption laser irradiance has the opposite effect. The enhancement suggests extensive gas-phase ion-molecule reactions after irradiation by the desorption laser has ceased.

引用

页码：393 / 398

页数：6