Ion mobility is a new separation technique that can be coupled with high performance liquid chromatography (HPLC) or ultra-performance liquid chromatography (UPLC). Variances in cross-sectional ionic areas of different molecules create differential speeds through a gas allowing for millisecond separations. Combining ion mobility with both liquid chromatography and mass spectrometry with fragmentation, separations can be achieved on the second (HPLC), millisecond (ion mobility), and microsecond (mass spectrometry) timescales. This orthogonal separation greatly cleans up mass spectral data of co-eluting peaks from the liquid chromatography and adds to the descriptive data of each ion. With descriptive data such as retention time, cross-sectional area, m/z ratio, and mass spectral fragmentation, many options become available for analytical analysis. Options ranging from descriptive data collation into instrument libraries to sensitivity enhancement for trace analysis will be explored in this chapter along with the description of different forms of ion mobility.
Part of the book: Analytical Liquid Chromatography
Gas chromatography mass spectrometry (GCMS) technology, whether in a laboratory or in the field allows scientists to identify and quantitate volatile and semi-volatile chemical compounds at low levels. It was not until the 1990s, well after the birth of GCMS in the 1950’s, that portable GCMS technology became possible. GCMS miniaturization along with a need for scientists to test samples outside of the laboratory drove the development of portable GCMS systems. Currently, scientists in the environmental, emergency response, government, military sectors, and private manufacturing industries use portable GCMS technology to monitor and quantitate various chemicals such as low levels of hazardous compound exposure in the environment. Successful implementation of portable GCMS also required that many sample preparatory techniques used in the laboratory must be modified for application in the field to maintain simplicity and robustness of the analysis of complex matrices like soil or water. This chapter will describe portable GCMS technology along with the current uses and sample preparatory techniques utilized.
Part of the book: Novel Aspects of Gas Chromatography and Chemometrics