Abundance Stability Study of α-H Cleavage Induced by Free Radical Center Based on Linear Ion Trap Mass Spectrometry
- VernacularTitle: 基于线性离子阱质谱的自由基中心诱导α-H断裂丰度稳定性研究
- Author:
Xin LU
1
Author Information
- Publication Type:Journal Article
- Keywords: Abundance stability; Free radical center; Space charge effect; Α-H fracture
- From: Chinese Pharmaceutical Journal 2020;55(2):141-147
- CountryChina
- Language:Chinese
- Abstract: OBJECTIVE: To study the response stability of free radical center-induced α-H cleavage on linear ion trap mass spectrometry (LTQ-MS), and discuss the interaction mechanism in ion trap and the effects of hydrogen and deuterium hybrid loss on quantitation precision. METHODS: The special cleavage mode of D6-ornithine lactam was used to distinguish different α-H cleavage, and the factors that might affect the abundance stability were inferred by mechanism discussion and falsification. RESULTS: The quantitation precision of ion pairs with only hydrogen loss(115.1→97.1;121.1→103.1) and threonine instead of D6-ornithine lactam (115.1→70.1;120.1→74.0)was significantly better than that of ion pairs involving hydrogen-deuterium hybrid loss(115.1→70.1;121.1→75.1). When 115.1→70.1;121.1→75.1 were used, the quantitation precision of tandem quadrupole mass spectrometry was significantly better than that of LTQ-MS. CONCLUSION: The instability of ion abundance, the effect of quality discrimination and the effect of ion concentration saturation are not significant factors affecting the stability of LTQ detection signal. Combined with the fragmentation characteristics of D6-ornithine lactam and Matthew′s equation, it is proposed that the space charge in the trap is the main reason for the instability of the detection signal.
