Abstract <p>During the synthesis of isopropyl alcohol by hydrogenation of acetone it is necessary to monitor the contents of trace impurities in the hydrogen, since its purity determines product quality, and CO and CO₂ impurities act as catalytic poisons for this reaction. At the Omsk Kauchuk plant, hydrogen purity is determined by gas chromatography using two different chromatographs: a laboratory unit and an online unit. A comparison of parallel determinations of hydrogen concentration revealed a discrepancy on the order of 10 wt %, while the process chromatograph did not detect CO and CO₂ impurities that the laboratory chromatograph measured at 0.10 and 0.016 wt %, respectively; the nitrogen content was also substantially underestimated. Based on the study, it was established that the packing sorbent of the packed column of process chromatograph is unsuitable for determining CO₂, which distorts the hydrogen measurement results. Accordingly, alternative packed columns containing a sorbent selective for CO₂ were proposed for use with the process chromatograph and the column should be periodically heated to remove volatile contaminants.</p>