In GC, why is the choice of carrier gas important, and what are typical options?

In GC, why is the choice of carrier gas important, and what are typical options?

• A. The carrier gas choice has no impact on performance.
• B. Common options are helium, hydrogen, and nitrogen; helium provides high efficiency and stable baselines but is costly; hydrogen offers faster runs but is flammable; nitrogen is used for slower separations.
• C. Only air can be used as carrier gas.
• D. Nitrogen always provides the shortest run times.

Answer: (B)