Open AccessOptimized low-level liquid scintillation spectroscopy of 35 S for atmospheric and biogeochemical chemistry applications
Author(s) -
Lauren A. Brothers,
G. Domínguez,
A. Abramian,
A. Corbin,
Ben Bluen,
M. H. Thiemens
Publication year - 2010
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0901168107
Subject(s) - biogeochemical cycle , troposphere , atmospheric chemistry , environmental science , atmosphere (unit) , atmospheric sciences , aerosol , stratosphere , liquid scintillation counting , sulfur dioxide , environmental chemistry , range (aeronautics) , chemistry , meteorology , ozone , radiochemistry , physics , materials science , inorganic chemistry , composite material
Anthropogenic activities, dominated by emissions of sulfur dioxide (SO2 ), have perturbed the global sulfur (S) cycle. Uncertainties in timescales of S transport and chemistry in the atmosphere lead to uncertainties in the predicted impact of S emissions. Measurements of cosmogenic35 S may potentially be used to resolve existing uncertainties in the photochemical and chemical transformation of S in the environment. The lack of a simple, effective, and highly sensitive technique to measure35 S activity in samples with low activities may explain the scarcity of published measurements. We present a set of new sample handling and measurement procedures optimized for the measurement of35 S in natural samples with activities as low as 0.20 dpm above background (2σ , integration time = 2 hr). We also report simultaneous measurements of aerosol () and gas phase () collected at inland and coastal locations; the range of observed activities corresponds to SO2 residence lifetimes of 0.2 ± 0.04 (coastal) - 22.3 d ± 0.04 (inland). These optimized techniques offer the potential for resolving atmospheric processes that occur on 6–12-hour timescales as well as resolving transport phenomena such as stratospheric mixing into the troposphere.