What GC column is able to separate hydrogen, oxygen, and nitrogen with helium as carrier gas?
Best choice would be a mole sieve column. Pic is from an older Agilent catalog.
Be aware:
It's best to use a pre-column that can be backflushed to keep heavy components off the mole sieve column. CO2, water, and C2 and heavier hydrocarbons can take a very long time to elute from the column. A PLOT Q column is frequently used for this.
If you are using TCD with helium carrier/reference, hydrogen will have a very low response. (Typically a second TCD with argon or nitrogen carrier is used for hydrogen quantitation.)