Analysis for impurities in helium using the helium ionization detector

"This Bureau of Mines report describes a chromatographic method for analyzing impurities in helium that utilizes a helium carrier gas containing 25 to 30 ppm Ne. An example of the effect of trace amounts of nitrogen, methane, and moisture on the detector's response is shown. The added neon in the carrier does away with irregularities of the analysis that were experienced when the carrier contained up to 3 ppm Ne. The addition of 25 to 30 ppm ne causes a loss of sensitivity, but the remaining sensitivity is adequate for routine analyses. The high-neon carrier allows positive and more linear responses for eight impurities: neon, hydrogen, argon, oxygen, nitrogen, methane, carbon dioxide, and ethane. Neon concentration levels of 0.02 to 125 ppm in helium carrier gases were studied. The high-neon carrier has been in successful routine use in Bureau of Mines helium facilities since October 1981." - NIOSHTIC-2NIOSH no. 10004440198