Magnesium Perchlorate as an Alternative Water Trap in AMS Graphite Sample Preparation: A Report On Sample Preparation at Kccams at the University of California, Irvine

We present a brief discussion of sample preparation procedures at the Keck Carbon Cycle Accelerator Mass Spectrometer (KCCAMS), University of California, Irvine, and a systematic investigation of the use of Mg(ClO 4 ) 2 as an absorptive water trap, replacing the standard dry ice/ethanol cold finger in graphite sample preparation. We compare high-precision AMS measurement results from oxalic acid I and USGS coal samples using Mg(ClO 4 ) 2 under different conditions. The results obtained were also compared with those achieved using the conventional water removal technique. Final results demonstrate that the use of Mg(ClO 4 ) 2 as an alternative water trap seems very convenient and reliable, provided the Mg(ClO 4 ) 2 is replaced frequently.