Aksyonov S A, Williams P
Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1604, USA.
Rapid Commun Mass Spectrom. 2001;15(21):2001-6. doi: 10.1002/rcm.470.
Impact desolvation of electrosprayed microdroplets (IDEM) is a new method for producing gas-phase ions of large biomolecules. Analytes are dissolved in an electrolyte solution which is electrosprayed in vacuum, producing highly charged micron and sub-micron sized droplets (microdroplets). These microdroplets are accelerated through potential differences approximately 5 - 10 kV to velocities of several km/s and allowed to impact a target surface. The energetic impacts vaporize the droplets and release desolvated gas-phase ions of the analyte molecules. Oligonucleotides (2- to 12-mer) and peptides (bradykinin, neurotensin) yield singly and doubly charged molecular ions with no detectable fragmentation. Because the extent of multiple charging is significantly less than in atmospheric pressure electrospray ionization, and the method produces ions largely free of adducts from solutions of high ionic strength, IDEM has some promise as a method for coupling to liquid chromatographic techniques and for mixture analysis. Ions are produced in vacuum at a flat equipotential surface, potentially allowing efficient ion extraction.
电喷雾微滴碰撞去溶剂化（IDEM）是一种产生大型生物分子气相离子的新方法。分析物溶解在电解质溶液中，该溶液在真空中进行电喷雾，产生高电荷的微米和亚微米尺寸的液滴（微滴）。这些微滴通过大约5 - 10 kV的电位差加速到几千米每秒的速度，并使其撞击目标表面。高能碰撞使液滴汽化并释放出分析物分子的去溶剂化气相离子。寡核苷酸（2至12聚体）和肽（缓激肽、神经降压素）产生单电荷和双电荷分子离子，且没有可检测到的碎片。由于多重电荷化程度明显低于大气压下的电喷雾电离，并且该方法产生的离子基本上不含来自高离子强度溶液的加合物，所以IDEM作为一种与液相色谱技术联用和用于混合物分析的方法具有一定前景。离子在真空中的平坦等势面上产生，这有可能实现高效的离子提取。
