Development and application of ion mobility spectrometry.

点击翻译按钮获取中文摘要

Fundamental study and development of the atmospheric pressure ion mobility spectrometry (IMS) was carried out.Carbon dioxide, reported not suitable for the medium in ion mobility study, was applied to the carrier gas and drift gas in IMS. Both positive and negative ions of carboxylic acid esters gave similar spectrum as obtained in nitrogen drift gas except the very low mobility due to the formation of cluster ions.Reduced mobility of various compounds such as nitrogen containing heterocyclic compounds, polyaromatics, alkylamine, amino acid and carboxylic acid esters etc. have been studied in relation to the molecular size and shape. A single peak method is used to calculate a resolution value equal to the theoretical number of peaks that can be separated prior to the peak from which the measurements are made. To predict selectivity of an ion mobility detector for GC and SFC, a term "reduced drift constant" was defined. With this value, ion mobility separation between two ions can be predicted from literature data.A capillary supercritical fluid chromatograph (SFC) with on-column UV detector and IMS was constructed. Carbon dioxide was used as both the chromatographic mobile phase and the ion mobility drift gas. Ion mobility spectra at appropriate chromatographic retention times produced distinct spectra for each of the compounds. The high sensitivity of ion mobility detection over UV detection can be achieved.New polyacrylic liquid crystalline compounds were synthesized as selective liquid phases for capillary column in GC and SFC.Quadrupole mass spectrometry was combined after the IMS drift tube and constructed the GC/SFC-IMS-QMS instrument to develop a system which can achieve highly selective and sensitive detection.