4 Channel HPLC Solvent Degasser - LHDEG/4

Key benefits:
• Improves baseline stability and reduces noise
• Improves pump performance — fewer bubbles, less cavitation
• Improves laboratory safety — no escape of solvent vapours to the atmosphere
• Prevents bubble formation in detectors and solvent mixing systems
• Does not cause mixed solvent depletion
• Uses only mains power — no need for high pressure gas cylinders

Why you need a degasser:
It is important to degas solvents in HPLC, to reduce bubble formation when solvents are mixed and also to increase sensitivity and reduce baseline noise, particularly at low UV wavelengths. Although this can be done by bubbling helium through the solvents, this is expensive and results in the need to check and change cylinders. Helium degassing can also introduce unwanted environmental pollution into the laboratory atmosphere.

How it works:
On-line degassing has been shown to be the more effective at removing dissolved gas from mobile phases than sonication or helium-sparging. Up to five solvent lines can be degassed simultaneously by one unit. The extremely low volume of each PTFE® AF channel (480 µl) offers very quickly equilibration and very short start-up times.

PTFE® AF is 50x more permeable than PTFE® PTFE
The new PTFE® AF membrane outperforms the older PTFE® PTFE membranes used in many other degassing systems today. This translates into the ability to use shorter tubing for removal of dissolved gasses.

• Considerably shorter equilibration / re-equilibration times
• Very easy to prime
• Short vacuum pull-down times, typically 3 minutes
• PTFE® AF has the ability to remove pre-pump bubbles formed by cavitation vs bubbles formed by off-the-floor eluent reservoirs are less of a reliability issue

Vacuum pump technology
These HPLC solvent degassers feature the ZHCR® (Zero Hysteresis Constant Run) stepper motor driven vacuum pump, specifically designed and developed for membrane degassing of HPLC mobile phase.

This permits the pump to maintain a constant vacuum level set-point (50 mmHg) by varying the RPM of the stepper motor. The pump initially runs at a high speed which provides for a quick pull-down and, as it approaches the vacuum control point, the RPM is gradually reduced until the desired vacuum level is reached.

This patented control strategy allows the solvent degasser to maintain a virtually constant vacuum that is unaffected by varying degassing loads. As a consequence, fluctuations in baseline due to vacuum hysteresis are eliminated by not having the pump repeatedly stop and start as is done in many older and existing systems.