The equilibration of ortho- and para-hydrogen on alumina at 77 °K and its influence on the determination of small amounts of excess para H2, D2, and HD in the presence of large amounts of normal H2

Abstract

When alumina is activated sufficiently to separate excess para H2, D2, and HD in a gas–solid chromatographic column at 77 °K using normal H2 as the carrier gas, appreciable ortho-para equilibration takes place on the alumina. A kinetic study of the equilibration process was made, as the result of which procedures were established which made it possible to determine small concentrations of excess para H2 in the presence of normal H2. If D2 and/or HD are also present in the sample, the observed peak area for excess para H2 is subject to correction terms which are directly proportional to the concentrations of D2 and/or HD.