Variable splitter for regulation of the solvent evaporation rate in the coupling of liquid chromatography with gas chromatography

Abstract

SummaryA system is described which accelerates the solvent evaporation rate in the retention gap. The evaporation is due to a saturation effect of the carrier gas stream, and a considerable increase in evaporation rate is obtained by inserting a split outlet between the retention gap and the Capillary separation column in the gas chromatograph. By varying the backpressure of the splitter device, the flow rate through the retention gap can be adjusted and so too the evaporation rate. The evaporation process was monitored by inserting a detector in the split outlet line.The technique was applied to the on-line LC trace enrichmentlGC analysis of water containing a mixture of polycyclic aromatic hydrocarbons.

Sample Preparation for Chromatographic Analysis

“…Several groups have extended the use of the valve-retention gap interface to microbore LC columns with internal diameters up to about 3 mm [232][233][234][235][236][237][238][239][240][241]. The use of short retention gaps with complete or partial concurrent solvent evaporation has been established as the preferred transfer technique, Figure 8.2 0 [224].…”

Reversed‐phase liquid chromatography coupled on‐line with capillary gas chromatography II. Use of a solvent vapor exit to increase introduction volumes and introduction rates into the gas chromatograph

“…LC columns. The use of a solvent vapor exit in an on-column interface has been reported before, but in most applications only apolar solvents were used [5,14,15]. In the present work, however, the azeotropic acetonitrile/water mixture was used as LC eluent, and the potential drug, eltoprazine, was used as a model compound.…”