Nitrogen gas for LC/MS is needed to remove moisture, hydrocarbons and other contaminants, to minimize detector noise or drift and eliminate ghost peaks.

     Moisture purifiers are typically packed with molecular sieve that absorb water preventing degradation of hydrocarbon putifiers and detector noise.
     Hydrocarbon purifiers are packed with an activated charcoal that absorb hydrocarbons larger than methane, which cause baseline noise or drift or ghost peaks.
     Indicating hydrocarbon purifiers are packed an activated charcoal with indicator that remove hydrocarbons from gas and changes color to warn of system saturation.

     To meet the high flow needs of the LC/MS system, the hydrocarbon or moisture filled cartridges are positioned and placed in parallel. The incoming gas stream is split equally be-tween the cartridges and the two streams are rejoined after purification but before the gas exits the base plate.