Department of Chemistry, Kyungpook National University , 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea.
Bruker Daltonik GmbH, Fahrenheitrasse 4, 28359 Bremen, Germany.
Anal Chem. 2017 Nov 21;89(22):12101-12107. doi: 10.1021/acs.analchem.7b02644. Epub 2017 Nov 7.
Resolving power is a critical factor determining the quality of ultrahigh-resolving power mass spectra of crude oil. In this study, 7T Fourier-transform ion cyclotron mass spectrometry (FT-ICR MS), equipped with quadrupole detection, was applied and evaluated for crude oil analysis for the first time. Four spectra were obtained from two oil samples using two ionization methods. Resolving power of 1500000 was observed at m/z 400 with 4 s transient signal. Comparison with literature reports revealed that the achieved resolving power was comparable with or superior to those obtained from instruments using higher magnetic fields but without quadrupole detection. A total of 6000-10000 peaks with an S/N ratio of 3 or higher were observed from the obtained spectra and over 97% of the peaks could be assigned to appropriate chemical formulas with an error within 1 ppm. Double bond equivalents vs carbon number plots generated from the obtained data agreed well with those previously reported without quadrupole detection. Mass accuracy values of the assigned elemental formulas were examined and the average root-mean-square error was calculated to be only 160 ppb. Low unassignment rate of the observed peaks and strong agreement with previously reported results suggests that unwanted harmonics of reduced frequency are not significant for the data obtained with quadrupole detection. Overall, the data presented in this study show that FT-ICR MS equipped with quadrupole detection can be a powerful tool to examine complex mixtures like crude oil. To the best of our knowledge, this is the first paper reporting application of FT-ICR MS equipped with quadrupole detection for the oil analysis.
分辨率是决定原油超高分辨质谱质量谱图质量的关键因素。本研究首次应用配备四极检测的 7T 傅里叶变换离子回旋共振质谱（FT-ICR MS）对原油进行分析。使用两种电离方法从两个油样中获得了四个光谱。在 m/z 400 处观察到 1500000 的分辨率，瞬变信号为 4 s。与文献报道的结果相比，所达到的分辨率可与或优于使用更高磁场但无四极检测的仪器获得的分辨率相媲美。从获得的光谱中观察到 6000-10000 个 S/N 比为 3 或更高的峰，超过 97%的峰可以分配到适当的化学式，误差在 1 ppm 以内。从获得的数据生成的双键当量与碳数图与以前没有四极检测的报告非常吻合。所分配元素公式的质量精度值进行了检查，平均均方根误差计算为仅 160 ppb。观察到的峰的未分配率低，与以前报道的结果强烈一致，这表明带有四极检测的数据不受降低频率的不必要谐波的影响。总的来说，本研究中提供的数据表明，配备四极检测的 FT-ICR MS 可以成为分析复杂混合物（如原油）的强大工具。据我们所知，这是第一篇报道配备四极检测的 FT-ICR MS 用于油分析的论文。
