Capillary supercritical fluid hydrocarbons

A paper has been published showing the use of the photoionization detector [26], Polyaromatic hydrocarbons are very sensitive using the photoionization detector and the levels detected did not break any new ground in terms of sensitivity. It did inspire HNS Systems (Newtown MA, USA), who market a photoionization detector, to try the detector with a capillary system, interfaced to a Lee Scientific 602 supercritical fluid chromatography (Lee Scientific, Salt Lake City, Utah, USA). 

Figure 12.21 SFC-GC heart-cut analysis of chrysene from a complex hydrocarbon mixture (a) SFC trace (UV detection) (b) GC trace without heart-cut (100% transfer) (c) GC trace of heart-cut fraction (flame-ionization detection used for GC experiments). Reprinted from Journal of High Resolution Chromatography, 10, J. M. Levy et al., On-line multidimensional supercritical fluid chromatography/capillary gas chromatography , pp. 337-341, 1987, with permission from Wiley-VCH.

Microwave induced plasma mass spectrometry has also been used as a detector for supercritical fluid chromatography (SFC) [113] for the separation of halogenated hydrocarbons. The design of an SFC-MIP interface must ensure that the frit restrictor temperature remains at a high temperature to prevent condensation of analytes. Stainless steel transfer lines may be used. The frit restrictor should be connected to a length of deactivated fused silica capillary, inserted through the transfer line, and positioned flush with the aluminum MIP torch inset (Fig. 10.21). 

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