Impurity analyses of high-purity carbon monoxide gas using micro gas chromatography for development as a certified reference material

► We analyzed impurities in a high-purity carbon monoxide gas of semiconductor grade. ► A compact micro gas chromatograph was used for the impurity analyses. ► High-accuracy calibration gas mixtures by gravimetric blending method were used. ► The concentration of helium was found to be much higher than the other impurities. ► The purity of the high-purity gas was around 99.996% based on our analyses.