The fine structure of isotopic peak distributions of glutathione in mass spectra is measured using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) at 12 and 15 T magnetic field, with an infinity cell and a dynamically harmonized cell (DHC) respectively. The resolved peaks in the fine structure of glutathione consist of ²H, ¹³C, ¹⁵N, ¹⁷O, ¹⁸O, ³³S, ³⁴S, ³⁶S, and combinations of them. The positions of the measured fine structure peaks agree with the simulated isotopic distributions with the mass error less than 250 ppb in broadband mode for the infinity cell and no more than 125 ppb with the DHC after internal calibration. The 15 T FT-ICR MS with DHC cell also resolved around 30 isotopic peaks in broadband with a resolving power (RP) of 2 M. In narrowband (m/z 307–313), our current highest RP of 13.9 M in magnitude mode was observed with a 36 s transient length by the 15 T FT-ICR MS with the DHC and 2ω detection on the 15 T offers slightly higher RP (14.8 M) in only 18 s. For the 12 T FT-ICR MS with the infinity cell, the highest RP achieved was 15.6 M in magnitude mode with a transient length of 45 s. Peak decay was observed for low abundance peaks, which could be due to the suppression effects from the most abundant peak, as result of ion cloud Coulombic interactions (space-charge).

中文翻译：

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使用傅里叶变换离子回旋共振质谱法测量同位素峰分布的精细结构：Infinity ICR 电池和动态协调 ICR 电池之间的比较

质谱中谷胱甘肽同位素峰分布的精细结构使用傅里叶变换离子回旋共振质谱 (FT-ICR MS) 在 12 和 15 T 磁场下测量，分别具有无限单元和动态协调单元 (DHC)。谷胱甘肽精细结构中的分辨峰由² H、¹³ C、¹⁵ N、¹⁷ O、¹⁸ O、³³ S、³⁴ S、³⁶S，以及它们的组合。测量的精细结构峰的位置与模拟同位素分布一致，在无限电池的宽带模式下质量误差小于 250 ppb，内部校准后 DHC 的质量误差不超过 125 ppb。带有 DHC 池的 15 T FT-ICR MS 还在宽带中分辨了大约 30 个同位素峰，分辨能力 (RP) 为 2 M。在窄带 ( m / z307–313），我们目前在幅度模式下的最高 RP 为 13.9 M，通过 15 T FT-ICR MS 与 DHC 观察到 36 秒的瞬态长度，15 T 上的 2ω 检测在 15 T 上提供略高的 RP（14.8 M）只有 18 秒。对于具有无限单元的 12 T FT-ICR MS，在幅度模式下达到的最高 RP 为 15.6 M，瞬态长度为 45 s。对于低丰度峰观察到峰衰减，这可能是由于离子云库仑相互作用（空间电荷）导致最丰度峰的抑制效应。