Hydrogen supercritical fluid chromatography

Universal sulfur-selective detectors for GC or supercritical fluid chromatography (SFC), that incorporate a cool hydrogen-rich flame or closed hydrogen/ air burner have been developed and are now commercially available. Combustion products are transferred via a connecting line to a low-pressure reaction cell, where they are mixed with ozone. Although sulfur monoxide is believed to be the common intermediate that reacts with ozone to form the excited sulfur dioxide emitter, it is not necessarily the product of the first conversion step, which has caused debate between instrument manufacturers. One proposed mechanism proceeds as shown in reaction [VI] and it was suggested that the reduced sulfur species could be H2S ... 

Supercritical Fluid. To be useful as a mobile phase in chromatography, a supercritical fluid must have a relatively low critical temperature and pressure, and a relatively high density/solvating power at experimentally accessible pressures and temperatures. The former criterion excludes water and most common organic solvents, whereas the latter excludes such low-boiling substances as helium, hydrogen, and methane. Commonly used fluids are listed in Table I. 

The reaction between ozone and SO (see reaction [V]) elicits chemiluminescence between 260 and 480 nm and is the foundation of an alternative sulfur detector that is commercially available for use with gas, supercritical fluid, and liquid chromatography. The SO is created from sulfur-containing analytes by burning the chromatographic effluent in a hydrogen flame ... 

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