在正常毛细管温度(200℃)下,利用电喷雾质谱(ESI—MS)研究了NaNO3、KNO3、NaNO2和KNO2形成的新型簇合物离子,采用电喷雾多级串联质谱(ESI—MS*)研究了簇合物离子裂解行为。实验结果表明:NaNO3和KNO3溶液产生的簇合物离子及这些离子的裂解方式相似;NaNO2溶液产生的簇合物离子比NaNO3和KNO3溶液产生的复杂;KNO2溶液产生了含有Na+离子的簇合物离子,通过分析KNO2簇合物离子的裂解行为证明了Na+与NO2-的亲合势大于K+。此外,还研究了离子源金属毛细管温度和溶液浓度对簇合物离子形成的影响。
New typical cluster ions of alkali metal nitrates and nitrites were studied in the normal capillary temperature (200℃) by electrospray ionization mass spectrometry (ESI-MS) , and their fragmentation behavior was investigated by electrospray multi-stage tandem mass spectrometry (ESI-MSn). The results indicate: (1) There is a similar behavior between cluster ions of NaNO3 solution and those of KNO3 solution studied both by ESI-MS and ESI-MSn; (2) The cluster ions of NaNO: solution are more complicated than those of NaNO3 and KNO3 solution studied by ESI-MS; (3) cluster ions containing Na + ions were produced from KNO2 solution during the electrospray process, and it is elucidated that the affinity of Na + ion to NO2- is bigger than that of K ~ ion by analyzing their ESI-MSn behavior. In addition, the effects of the capillary temperature of the ESI source and the solution concentration on the formation of the cluster ions were also interrogated.