Automatic ⁴⁰Ar/³⁹Ar Dating Techniques Using Multicollector ARGUS Ⅵ Noble Gas Mass Spectrometer with Self-Made

A new fully automatic ⁴⁰Ar/³⁹Ar laboratory with a Thermo Scientific^© ARGUS Ⅵ mass spectrometer has been established in China University of Geosciences (Wuhan). We designed and developed a mini efficient preparation system (80 mL), a CO₂ laser for heating samples, a crusher for extracting fluid inclusions within K-poor minerals and an air reservoir (31 L) and pipette (0.1 mL) system. The ARGUS Ⅵ mass spectrometer is operated by the Qtegra Noble Gas software, which can control the peripheral accessories, such as pneumatic valves, CO₂ laser and crusher through a PeriCon (peripheral controller). The experimental procedures of atmospheric argon analyses, ⁴⁰Ar/³⁹Ar dating by laser stepwise heating and by progressive crushing in vacuo, can be fully automatically performed. The weighted mean of atmospheric ⁴⁰Ar/³⁶Ar ratios is 302.22±0.03 (1σ, MSWD=0.74, n=200), indicating that air reservoir and pipette system and the whole instrument system are very stable. This laboratory is a successful pioneer example in China to establish a new noble gas laboratory with self-made peripheral accessories expect for the mass spectrometer.