BASi LC-26D On-Line Degasser

The LC-26D On-Line Degasser is an invaluable accessory for gradient liquid chromatography, microbore liquid chromatography, or for any application where high pressure flowing solvent is involved. When connected in-line between the LC solvent supply and pump, the degasser automatically removes dissolved gas from up to four separate reservoirs of mobile phase. High flow rates can be accommodated by passing the solvent through multiple channels. A rugged on-line device, the degasser is more convenient and effective than other common methods, such as: helium sparging, ultrasonication, filtration, heating and vacuum aspiration. Without some form of degassing, the system may be subject to outgassing at the pump or after the column. This can create bubbles that affect pump performance or become trapped in the detector cells and produce undesirable noise. This can be a particular problem with small volume detector cells and the low flow rates encountered with microbore chromatography.

The heart of the degasser is a short length of Teflon AF(480 microliter capacity) located in a vacuum chamber. Within this chamber a partial vacuum is maintained by a constantly running, low rpm vacuum pump. The dissolved gasses in the solvent are pulled through the tubing wall by the differential pressure. At startup the vacuum pump is ramped to high rpm to rapidly exhaust atmosphere from the vacuum chamber. When the vacuum passes a specified performance level, the vacuum pump is ramped to the low rpm--continuous run mode. A microprocessor monitors absolute pressure and rate of change of vacuum level within the chamber. A persistent change in either parameter indicates a leak and the pump turns off. Three LEDs on the front panel are linked to the microprocessor to indicate system status. Low oxygen-permeability Teflon tubing, as well as standard Teflon tubing, and necessary connectors are included.