| The catalytic properties of {dollar}rm YBasb2Cusb3Osb7{dollar}, the recently discovered high temperature superconductor, were studied in a gas chromatography detection system. The powdered superconducting perovskite material was substituted for gold in a redox chemiluminescence detector (RCD), in which the oxidation of organic analytes by NO{dollar}sb2{dollar} produces a pulse of NO which is measured downstream. Differences in sensitivity of response of components in an analyte mixture were measured at varying catalyst bed temperatures and flow rates through the reaction zone. Of the compounds studied, alcohols and alkenes were the most sensitively detected under all conditions, while benzene and saturated hydrocarbons gave the weakest response. The detection limit for ethanol was 0.5 ng, with a selectivity ratio of 379 relative to benzene. Higher catalyst temperatures and lower flow rates yielded the most sensitive detection of all analytes studied, but better selectivity was attained using lower temperatures and higher flow rates. Application of the system to the analysis of methyl t-butyl ether in gasoline and of formaldehyde was also studied.; The {dollar}rm YBasb2Cusb3Osb7{dollar} catalyst was also compared to various gold catalysts in RCD; gold supported on iron oxide was the most active of all catalysts studied, while iron oxide alone gave a weak response to analytes, and was very active in the catalytic decomposition of NO{dollar}sb2{dollar} to NO. The gold catalysts detected CO, H{dollar}sb2{dollar}, and benzene, while the {dollar}rm YBasb2Cusb3Osb7{dollar} catalyst showed only a weak response to these analytes.; The RCD was also employed to detect NO formed from the interaction of {dollar}rm YBasb2Cusb3Osb{lcub}7-x{rcub}{dollar} with NO{dollar}sb2{dollar} during a rapid heating and cooling cycle. The response for photon counts per mg of sample vs. oxygen content of {dollar}rm YBasb2Cusb3Osb{lcub}7-x{rcub}{dollar} was linear for x = 0.1-0.9, when sample sizes were kept smaller than 4 mg. |
