Department of Chemistry and Biochemistry, Florida International University , Miami, Florida 33199, United States.
Bruker Daltonics Inc., Billerica, Massachusetts 01821, United States.
Anal Chem. 2018 Feb 20;90(4):2446-2450. doi: 10.1021/acs.analchem.7b04053. Epub 2018 Feb 8.
In this work, nonlinear, stepping analytical mobility scan functions are implemented to increase the analytical separation and duty cycle during tandem Trapped Ion Mobility Spectrometry and FT-ICR MS operation. The differences between linear and stepping scan functions are described based on length of analysis, mobility scan rate, signal-to-noise, and mobility resolving power. Results showed that for the linear mobility scan function only a small fraction of the scan is sampled, resulting in the lowest duty cycle 0.5% and longest experiment times. Implementing nonlinear targeted scan functions for analysis of known mobilities resulted in increased duty cycle (0.85%) and resolving powers (R up to 300) with a 6-fold reduction in time from 30 to 5 min. For broad range characterization, a nonlinear mobility stepping scan function provided the best sensitivity, resolving power, duty cycle (4%), and points per peak. The applicability of nonlinear mobility scan functions for the analysis of complex mixtures is illustrated for the case of a direct infusion of a MCF-7 breast cancer cell digest, where isobaric peptides (e.g., DFTPAELR and TTILQSTGK) were separated in the mobility domain (R: 110) and identified based on their CCS, accurate mass (R: 550k), and tandem MS using IRMPD in the ICR cell.
在这项工作中，实现了非线性、步进分析迁移率扫描函数，以在串联俘获离子迁移谱和 FT-ICR MS 操作期间增加分析分离度和工作周期。根据分析长度、迁移率扫描速率、信噪比和迁移率分辨率，描述了线性和步进扫描函数之间的差异。结果表明，对于线性迁移率扫描函数，仅对扫描的一小部分进行采样，导致最低的工作周期为 0.5%和最长的实验时间。对于已知迁移率的分析，实施非线性靶向扫描函数导致工作周期（0.85%）和分辨率（高达 300 的 R）增加，而时间从 30 分钟减少到 5 分钟。对于宽范围的特征描述，非线性迁移率步进扫描函数提供了最佳的灵敏度、分辨率、工作周期（4%）和每个峰的点数。非线性迁移率扫描函数在分析复杂混合物方面的适用性通过直接注入 MCF-7 乳腺癌细胞消化物的情况来说明，其中等压肽（例如，DFTPAELR 和 TTILQSTGK）在迁移率域（R：110）中分离，并基于它们的 CCS、精确质量（R：550k）和串联 MS 使用 ICR 细胞中的 IRMPD 进行鉴定。
