Liquid aerosol-phase chromatography

Hartshome, J. A. Speciation by Carbon Phase Liquid Chromatography-Inductively Coupled Plasma Emission Spectrometry and Studies of Aerosol Formation and Characteristics, M. S. Thesis, The Ohio State University, Columbus, 1996. 

Most instruments with an API source offer a choice of APCI or ESI. Detailed descriptions of these ionization methods are provided elsewhere a 3). Both rely on the formation of ions at atmospheric pressure in a source region separated from the high vacuum mass analyzer. Ions are transported to the analyzer through one or more differentially pumped skimmers or a heated capillary. Both APCI and ESI require aerosolization of the liquid eluent from the liquid chromatography (LC) column. The major difference lies in the method and phase of ionization. 

A rather broad applicability of FTIR as a detector in liquid chromatography can be achieved when the mobile phase is removed from the sample prior to detection. In this case the sample fractions are measured in a pure state without interference from solvents. Experimental interfaces to eliminate volatile mobile phases fromHPLC effluents have been tried with some success [133-135] but the breakthrough towards a powerful FTIR detector has only been achieved by Gagel and Biemann, who formed an aerosol from the effluent and sprayed it on a rotating aluminum mirror. The mirror was then deposited in a FTIR spectrometer and spectra were recorded at each position in the reflexion mode [136-138]. 

A selective liquid chromatography analysis of emu I si liable concentrates and aerosol formulations of pyrethroids, utilizing an IR spectrophotometer as a detector, was described by Papadopoulou-Mourkidou et al. (1981). The mobile phase consisted of various combinations of solvents, depending on the pyrethroids under study. 

---