Pan Qiong, Zhuo Xiaocun, He Chen, Zhang Yahe, Shi Quan
State Key Laboratory of Heavy Oil Processing, Petroleum Molecular Engineering Center (PMEC), China University of Petroleum, Beijing 102249, China.
ACS Omega. 2020 Mar 9;5(10):5372-5379. doi: 10.1021/acsomega.9b04411. eCollection 2020 Mar 17.
Molecular composition of dissolved organic matter (DOM) is a hot topic in subjects such as environmental science and geochemistry. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has been applied to molecular composition characterization of DOM successfully. However, high instrument and maintenance costs have constrained its wider application. A high-resolution Orbitrap mass spectrometer (Orbitrap MS) can provide approximately 500,000 resolving power (at / 200), which is potentially capable of characterizing the molecular composition of DOM. In this paper, the application of high-resolution Orbitrap MS was evaluated by comparing with FT-ICR MS in the aspect of resolution, mass distribution, detection dynamic range, and isotopic peak intensity ratio. The impact of instrument parameters of Orbitrap MS was further investigated, which includes ionization, ion transfer, and mass detection. The result shows that the high-resolution Orbitrap MS is capable or even preferable for molecular characterization of DOM. However, the peak intensity distributions are dependent on the instrument parameters, which could affect the environmental impact assessment caused by the sample itself. The result indicates that development of a universal and comparable method is of great demand.
溶解有机物（DOM）的分子组成是环境科学和地球化学等学科的热门话题。傅里叶变换离子回旋共振质谱（FT-ICR MS）已成功应用于DOM的分子组成表征。然而，仪器和维护成本高昂限制了其更广泛的应用。高分辨率轨道阱质谱仪（Orbitrap MS）可提供约500,000的分辨率（在m/z 200处），有潜力表征DOM的分子组成。本文通过在分辨率、质量分布、检测动态范围和同位素峰强度比方面与FT-ICR MS进行比较，评估了高分辨率Orbitrap MS的应用。进一步研究了Orbitrap MS仪器参数的影响，包括电离、离子转移和质量检测。结果表明，高分辨率Orbitrap MS能够甚至更适合用于DOM的分子表征。然而，峰强度分布取决于仪器参数，这可能会影响由样品本身引起的环境影响评估。结果表明，迫切需要开发一种通用且可比的方法。
