Department of Chemistry , Washington State University , Pullman , Washington 99164 , United States.
Anal Chem. 2019 Jan 15;91(2):1432-1440. doi: 10.1021/acs.analchem.8b04175. Epub 2019 Jan 2.
When coupling drift-tube gas-phase ion mobility separations with ion trapping mass analyzers an integrative, stepped approach to spectral reconstruction is a logical, yet highly inefficient means to determine gas-phase mobility coefficients. This experimental mode is largely predicated on the respective time scales of the two techniques each requiring tens of milliseconds to complete under routine conditions. Multiplexing techniques, such as Fourier and Hadamard based techniques, are a potential solution but still require extended experimental times that are not fully compatible with modern front-end separation schemes. Using a basis pursuit denoising (BPDN) approach to deconvolute Fourier transform ion mobility mass spectrometry (FT-IMMS) drift time spectra, we demonstrate significant time savings while maintaining a high degree of spectral resolution and signal-to-noise ratio. Under ideal conditions, the FT-IMMS operates with increased ion transmission (up to 25%); however, the linear chirp that spans into the kHz range often leads to significant levels of ion gate depletion, which limit both resolving power and ion transmission. The method proposed in this manuscript demonstrates the potential to reduce IMS acquisition time while simultaneously maximizing spectral resolution at longer effective gate pulse widths compared to the traditional set of multiplexing and signal averaging experiments.
当将漂移管气相离子迁移率分离与离子阱质谱分析器耦合时，综合的、分步的光谱重建方法是一种逻辑上但效率极低的确定气相迁移率系数的方法。这种实验模式主要基于这两种技术各自的时间尺度，每种技术在常规条件下都需要几十毫秒才能完成。多路复用技术，如傅里叶和哈达玛基于技术，是一种潜在的解决方案，但仍然需要扩展的实验时间，这与现代前端分离方案不完全兼容。我们使用基追踪去卷积（BPDN）方法对傅里叶变换离子迁移率质谱（FT-IMMS）的漂移时间谱进行解卷积，在保持高分辨率和信噪比的同时，显著节省了时间。在理想条件下，FT-IMMS 具有更高的离子传输率（高达 25%）；然而，线性啁啾扩展到 kHz 范围通常会导致离子门损耗的显著水平，这限制了分辨率和离子传输率。本文提出的方法具有在更长的有效门脉冲宽度下同时最大化光谱分辨率的潜力，与传统的多路复用和信号平均实验相比，同时减少 IMS 采集时间。
