Basanta M, Singh D, Fowler S, Wilson I, Dennis R, Thomas C L P
The School of Medicine, The University of Manchester, Manchester, UK.
J Chromatogr A. 2007 Nov 30;1173(1-2):129-38. doi: 10.1016/j.chroma.2007.09.082. Epub 2007 Oct 11.
Enhancing the analytical space of differential mobility spectrometry with dispersion field amplitude programming was proposed. Six volatile organic compound candidate breath markers, 1,3-butanediol, butanone, ethylbenzene, heptan-2-one, nonanal, and o-xylene were used to characterise the effect of programming the amplitude of the dispersion field on the sensitivity, and resolution of the responses observed. Sensitivity followed two patterns of behaviour. Sensitivity to heptan-2-one and 1,3-butanediol increased to a maximum at approximately 20 kV cm(-1), attributed to dissociative ionisation effects. The remaining four compounds' responses were dominated by wall-loss phenomena resulting in a constant reduction in sensitivity as dispersion field amplitude was increased. The effect of the dispersion field on analytical space was pronounced. At a field strength of 18 kV cm(-1) protonated monomers and proton-bound dimers could be observed within the chromatographic responses for the carbonyl compounds. Dissociative ionisation products were also discerned for 1,3-butanediol and butanone. The ion chemistry of the two hydrocarbons was not affected by the dispersion field amplitude. Resolution of the product ions and their separation from the reactant ion peaks increased significantly with increasing dispersion field amplitude. With a range of behaviours observed. Peak resolutions increased from the range 0 to 1.2 to 1.2 to 7, while resolving power increased from 0 (at low dispersion field amplitudes) to the range 0.2-6 at 20-24 kV cm(-1). The effect of programming the dispersion field amplitude on a "real-life" application was demonstrated with replicate breath samples obtained from a subject with chronic obstructive pulmonary disease.
提出了通过色散场振幅编程来扩展差分迁移谱的分析空间。使用六种挥发性有机化合物候选呼吸标志物，即1,3 - 丁二醇、丁酮、乙苯、2 - 庚酮、壬醛和邻二甲苯，来表征色散场振幅编程对灵敏度以及所观察到的响应分辨率的影响。灵敏度呈现出两种行为模式。对2 - 庚酮和1,3 - 丁二醇的灵敏度在约20 kV cm⁻¹时增加到最大值，这归因于离解电离效应。其余四种化合物的响应主要受壁损失现象支配，导致随着色散场振幅增加灵敏度持续降低。色散场对分析空间的影响很显著。在18 kV cm⁻¹的场强下，在羰基化合物的色谱响应中可以观察到质子化单体和质子结合二聚体。对于1,3 - 丁二醇和丁酮也能辨别出离解电离产物。两种烃类的离子化学性质不受色散场振幅的影响。随着色散场振幅增加，产物离子的分辨率及其与反应物离子峰的分离显著提高。观察到一系列行为。峰分辨率从0至1.2的范围增加到1.2至7，而分辨能力从低色散场振幅下的0增加到20 - 24 kV cm⁻¹时的0.2 - 6范围。通过从一名慢性阻塞性肺疾病患者获得的重复呼吸样本，证明了色散场振幅编程对“实际”应用的影响。
