用AxION分析非处方药Melatonin脑白金_褪黑素
1. Operating the TOF MS in trap (vs. pulse) mode provided a 3 to5 fold improvement in sensitivity. The increased sensitivity allowed additional impurities to be detected and measured in an OTC melatonin sample that were not observed in pulse mode.
2. The accurate mass measurement capability of the AxION 2 TOF could easily distinguished between elemental compositions C14H20N2O3 (m/z = 265.1547) and C13H16N2O4(m/z = 265.1183).
This provided the confirmation that a previously published structure proposed from data provided by a triple quadrupole MS was incorrect for a specific melatonin impurity.
3. The significant improvement in sensitivity gained from operating the AxION TM 2 TOF in trap mode along with the mass measurement accuracy allowed the dentification of additional melatonin impurities. These included N1-acetyl-N2-formyl-5-methoxykynurenin (AFMK) as well as melatonin dimers not observed in previously published work.