Abstract: Asuccessful analysis of silver was reported utilizing laser desorption/ionization time of flight mass spectrometry(LDI/TOF-MS) in this paper. The silver cluster ions Ag_n⁺ and Ag_n O⁺(n =2～5) were formed during laser desorption/ionization. In the presence of I^-, K⁺ and Na⁺, the peaks corresponding to the cluster ions [Ag_nI_n-1]⁺(n =2～6) and the adduct ions [AgI]⁺, [AgI]Na⁺ and [AgI]K⁺ were observed in the positive ion spectrum; the peaks corresponding to [Ag_n I_n+1]^- (n =1～3) were found in the negative ion spectrum, all of which accompanied by sliver isotope distribution. The formation of silver cluster ions was accomplished through two-stage reaction: the first step was the generation of clusters, which was followed by the processes of photoionization and ion/molecule reaction.

Key words: Laser desorption/ionization, Time-of-flight mass spectrometry, Silver cluster ion