DRY ICE ACTIVE SORB
System: DRY ICE ACTIVE SORB
Customer: Scottish Universities Environmental Research Centre
Temperature Range: 6K - 500K
Cool down time 300K to 10K: Less than 1 hour
Vacuum: <1x10-9 torr
The DRY ICE ACTIVE SORB is a cryogenic cold trap capable of 6K operation with the ability to reach 10K in less than 1 hour. The sorb's chamber contains an absorption material which is cooled using a mechinical cryocooler. By crushing and heating the sample to high temperatures and feeding the resulting gas to the sorb, the gas will be trapped.
The absorption material is then heated in a highly controlled manner. As the temperature is stepped up the trapped gases reach their individual evaporation points. The release gas from the process is fed into a gas chromatography unit for analysis. A benefit of this technique is that using a stepped temperature increase allows for the separation of trapped gases. Volumes of each gas can therefore be measured seperately.
The fast cool down times were key for researchers at the Scottish Universities Environmental Research Centre as it enabled them to rapidly isolate neon from air as well as providing the ability to take repeated measurements over a relatively short space of time for their reasearch on the isotopic composition of air Ne.
'The neon (Ne) isotope composition of rocks, minerals and natural gases are powerful tracers of their origin and ultimately tell us much about the Earth’s volatile inventory. To calibrate the mass spectrometers, all labs worldwide use Ne extracted from air. Consequently, we need to know precisely the isotopic composition of air Ne. In order to achieve this, we have performed repeated high precision measurements of air-derived neon using a converted static vacuum mass spectrometer (ThermoFisher ARGUS VI). As neon makes up only 18 ppm of atmosphere the major challenge of this study was to be able to reproducibly and rapidly isolate the Ne from air, in particular to be free of contaminating species such as H2O, Ar and CO2. We specifically purchased an ICEoxford DRY ICE ACTIVE SORB equipped with a Sumitomo cold head for this work, which allowed us to both purify the Ne and to concentrate it close to the mass spectrometer in order to increase the precision of the isotope ratio measurements.
Although we didn’t make much of it in the paper, the DRY ICE ACTIVE SORB was integral to the study. We chose the ICE system because of the short time to cool to 30K (~45 min) and negligible time lag between charcoal and thermocouple attaining temperature. That meant that Ne purification time was very short, allowing us to generate a huge data set in four weeks. In addition, the ease of automation of the system and the reproducible performance meant that subtle isotopic fractionation of Ne during the purification process was minimised.
We found Chris and the team to be extremely knowledge-able and responsive during discussion of the configuration of our instrument. Fitting a second heater on the radiation shield is a case in point. This shortens the time taken to release the Ne from the system and provides better temperature control. They were supportive post-purchase, assisting us in the automation process. We will undoubtedly continue to work with ICEoxford in the future.'
Fin Stuart and Domokos Gyore, Scottish Universities Environmental Research Centre (2020)