Gas streams from chemical systems are often quantified using gas chromatography, but current methods have limitations. A new approach using a TCD-FID detection system with a methanizer was developed to improve accuracy. By analyzing gas streams from a catalytic reactor, it was found that the internal standard method provided highly accurate quantification and meaningful carbon balances, unlike the external standard method. This study emphasizes the importance of careful application of chromatographic methods when studying gas system reactivity.