Jump to main content
Jump to site search


Optimizing the analyte introduction for 14C laser ablation-AMS

Author affiliations

Abstract

Recently a novel approach enabling spatially resolved analyses of radiocarbon (14C) in carbonates has been introduced, combining laser ablation with accelerator mass spectrometry (LA-AMS). Here, we present a comprehensive study to find optimum working conditions for LA-AMS. The stepwise optimization and characterization process comprises (i) finding a suitable laser source for the ablation of carbonates with highest CaCO3 to Cgas (i.e. CO2 or CO) conversion rate, (ii) studying different capillaries with different gas flow resistance that interface the LA-cell with the ion source of the AMS system, and (iii) determining the exchange rate of the LA cell and the width of a stalagmite's growth stop under real measurement conditions. Three laser sources (Nd:YAG@266 nm; Nd:YAG@213 nm; ArF excimer@193 nm) were tested at different fluences (3 and 23 J cm−2) for their Cgas-conversion efficiencies. Highest Cgas-conversion efficiencies of (70 ± 4)% were found with an ArF excimer laser, independently of laser fluence. The characterization of the system using different capillaries showed that gas flow rates applied in LA-AMS are more than a factor of five higher than for regular 14C AMS gas measurements, which probably results in reduced ionization efficiencies of the LA-AMS setup. An exchange rate of 10 min−1 is determined for the LA-cell design applied in this study by matching a 14C dataset derived by LA-AMS with modeled data (χ2-fit). Additionally, the model allowed to estimate the width of a growth stop in a stalagmite sample to be on the order of 0.25 mm.

Graphical abstract: Optimizing the analyte introduction for 14C laser ablation-AMS

Back to tab navigation

Supplementary files

Publication details

The article was received on 31 Mar 2017, accepted on 10 Jul 2017 and first published on 10 Jul 2017


Article type: Paper
DOI: 10.1039/C7JA00118E
Citation: J. Anal. At. Spectrom., 2017, Advance Article
  •   Request permissions

    Optimizing the analyte introduction for 14C laser ablation-AMS

    C. Welte, L. Wacker, B. Hattendorf, M. Christl, J. Koch, C. Yeman, S. F. M. Breitenbach, H. Synal and D. Günther, J. Anal. At. Spectrom., 2017, Advance Article , DOI: 10.1039/C7JA00118E

Search articles by author

Spotlight

Advertisements