The present invention relates to degassing a liquid, and more particularly to vacuum degassing of a liquid.
Degassing is practiced in liquid chromatography to extract air from mobile phase solvents since the presence of air (particularly oxygen) interferes with chromatographic analysis. See Bakalyar, Bradley and Honganen, The Role of Dissolved Gases in High-Performance Liquid Chromatography, Journal of Chromatography, 158 (1978) 277-293. As is shown in FIG. 1, the solvent is conducted from bottle 140 via tubing 150 to a degasser 170 where the solvent is degassed. The degassed solvent is conducted via tubing 172 to a liquid chromatography analytical system (LC analytical system) 180 for use as a mobile phase.
FIG. 2 shows a schematic diagram of a Shodex DEGAS KT-Series Degasser 170 available from Shodex Group of Tokyo, Japan. The solvent is pumped by a liquid chromatography pump (LC pump, not shown in FIG. 2) from bottle 140 via tubing 150 to a vacuum chamber 284. A vacuum pump 286 creates vacuum in vacuum chamber 284. As the solvent flows through tubing 287, gas dissolved in the solvent goes out through the wall of tubing 287 made of a special macromolecular film, and the solvent is thus degassed. A heater 288 under a vacuum chamber base 290 can be used to heat the solvent in vacuum chamber 284 to increase the effectiveness of degassing. The degassed solvent is pumped to a LC analytical system (not shown in FIG. 2) via tubing 292. See Shodex Operation Manual No. 781 for Shodex DEGAS KT-Series Degassing Device available from SHOWA DENKO K.K., Specialty Chemicals Division, Shodex (Separation & HPLC) Group, 13-9, Shiba Daimon 1-Chome, Minato-ku, Tokyo 105, Japan.1110
Shodex degasser 170 of FIG. 2 can be used to degas components of a mixed solvent as is schematically shown in FIG. 3. Each of bottles 300, 302 and 304 contains a component of the solvent. The components are conducted via respective tubings 308, 310 and 312 through degasser 170 in which each component is degassed. The degassed components are mixed, in a portion 316 of the tubing, into a solvent which is conducted to a liquid chromatography analytical system (not shown in FIG. 3) via tubing 318.
It is desirable to provide effective methods and apparatus for degassing of a liquid.