The long-lived noble-gas isotope 81Kr, 85Kr, and 39Ar are ideal tracers for environmental samples, and can be analyzed using the Atom Trap Trace Analysis (ATTA) method . 85Kr dating covers the age range of 2 – 50 years; 39Ar covers 50 – 1,400 years; 81Kr covers 40,000 – 1,300,000 years. In order to meet the increasing demands from the earth science community, we have established a new laboratory dedicated to radio-krypton and radio-argon dating. For Kr-dating, the required samples is 1-2 micro-liter STP of Kr gas, which can be extracted from 10-20 kg of water or ice; for 39Ar-dating, the sample size is 1-2 mL STP of argon, corresponding to a few kg of water or ice. We perform dating not only on groundwater but also on glacier ice and seawater. Here, we present both the latest technical development and earth science applications, including ATTA systems, degassing devices for groundwater, purification systems for dual krypton/argon output as well as examples of groundwater studies.
 Z.-T. Lu et al., Tracer applications of noble gas radionuclides in the geosciences, Earth-Science Reviews 138, 196-214 (2014)
http://atta.ustc.edu.cn/en-us/events/attaprimer.html or Google “ATTA primer”