HP-PLOT MoleSieve columns are recommended for the analysis of permanent and noble gases. HP-PLOT MoleSieve columns have a layer of 12-50 µm thick molecular sieve 5A zeolite immobilized inside the tubing. This provides excellent separation of small molecules such as nitrogen, oxygen, argon, methane, and carbon monoxide. The absorbent is bound to the inner surface of the fused silica tubing, reducing the chance of signal spikes due to particles breaking free and invading the system valve or detec- tor. This results in improved sensitivi- ty of detectors and overall system accuracy.