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Helium or vacum membranes - 2005/11/28 19:05
hi, everybody
I would like to have your opinion about the advantages of these type of deggasing
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Helium or vacum membranes - 2005/11/28 19:06
t's just a matter of costs! If you run one system and one bottle of Helium last for 1 year, stay with the Helium. If you run several systems, it's cheaper to have vacuum degassers. In both cases remember, that when starting on a Monday morning all tubes and capillaries must be flushed before connecting the column. Both degassing techniques need some time to be efficient. That's all. Gerhard
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Helium or vacum membranes - 2005/11/28 19:06
The reason helium is used is because it has much less solubility in water and solvents than air. Yes, air is replaced by helium, but because helium has much less solubility in liquids, the amount of helium in a helium saturated solution is normally insignificant to cause pumping problems.
Keep in mind, if degassing is simply being used to avoid pumping problems casue by out gassing during gradient formation, then it is not necessary to remove every molecule of gas present in the mobile phase. All the approaches work adequately and what is "best" is mainly a matter of convenience and reliability.
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