Record details

Title
    Technical Note: Evaluation of between-sample memory effects in the analysis of ?2H and ?18O of water samples measured by laser spectroscopes
Author
    Bogaard, T.A.
    Bonazza, M.
    Borga, M.
    Čejková, Bohuslava
    Fischer, B.M.C.
    Gobbi, A.
    Mantese, N.
    Michelini, M.
    Penna, D.
    Sobotková, M.
    Stenni, B.
    Šanda, M.
    Wassenaar, L.I.
    Wrede, S.
    Zuecco, G.
Language
    anglicky
Publication type
    článek v periodiku
Source title - serial
    Hydrology and Earth System Sciences
Vol./nr.
    Roč. 16, č. 10
Pages
    9
Year
    2012
Thesaurus term
    laser spectroscopy, memory effect, stable isotope, oxygen, hydrogen
Keyword
    2H
    18O
    Analysis
    Between-sample
    Effects
    Evaluation
    Laser
    Measured
    Memory
    Note
    Samples
    Spectroscopes
    Technical
    Water
Abstract (in english)
   This study evaluated between-sample memory in isotopic measurements of 2H and 18O in water samples by laser spectroscopy. Ten isotopically depleted water samples spanning a broad range of oxygen and hydrogen isotopic compositions were measured by three generations of offaxis integrated cavity output spectroscopy and cavity ringdown spectroscopy instruments. The analysis procedure encompassed small (less than 2? for 2H and 1? for 18O) and large (up to 201? for 2H and 25? for 18O) differences in isotopic compositions between adjacent sample vials. Samples were injected 18 times each, and the betweensample memory effect was quantified for each analysis run. Results showed that samples adversely affected by betweensample isotopic differences stabilised after seven-eight injections. The between-sample memory effect ranged from 14% and 9% for 2H and 18O measurements, respectively, but declined to negligible carryover (between 0.1% and 0.3% for both isotopes) when the first ten
   injections of each sample were discarded. The measurement variability (range and standard deviation) was strongly dependent on the isotopic difference between adjacent vials. Standard deviations were up to 7.5?for 2H and 0.54? for 18O when all injections were retained in the computation of the reportable -value, but a significant increase in measurement precision (standard deviation in the range 0.1 ?-1.0? for 2H and 0.05?- 0.17?for 18O) was obtained when the first eight injections were discarded. In conclusion, this study provided a practical solution to mitigate between-sample memory effects in the isotopic analysis of water samples by laser spectroscopy.
Contributor
    Česká geologická služba
Contributor code
    ČGS (RIV)
Source format
    R
Import date
    15. 10. 2014