Technical note: 21Ne in the CoQtz-N quartz standard material

Abstract

Intercomparison standards produced from mineral samples exposed to the natural cosmic ray flux are routinely used for interlaboratory comparison and normalization of measurements of the cosmogenic noble gases 3He and 21Ne. This effort is facilitated by the availability of multiple standard materials with a wide range of cosmogenic nuclide concentrations. The "CoQtz-N"quartz standard, which was originally produced and distributed as an intercomparison standard for cosmogenic 10Be and 26Al, has a significantly lower cosmogenic nuclide concentration than other mineral standards used for cosmogenic noble gas analysis and is therefore potentially useful for assessing the linearity of interlaboratory offsets across a wide range of concentrations. This paper reports 21Ne analysis of 13 aliquots of CoQtz-N, interspersed with 14 aliquots of the commonly used CRONUS-A quartz standard, in three analytical sessions on two noble gas mass spectrometer systems. The excess 21Ne concentration in CoQtz-N, normalized to the accepted value of 320 × 106 atoms g-1 for CRONUS-A, is 13.87 ± 0.24 × 106 atoms g-1. Alternatively, the ratio of excess 21Ne concentrations in CoQtz-N and CRONUS-A is 0.04330 ± 0.00077.