ISI Document Delivery No.: 278HU Times Cited: 0 Cited Reference Count: 23 Cited References: Annett AL, 2013, ANTARCT SCI, V25, P445, DOI 10.1017/S0954102012000892 Bourquin M, 2011, MAR CHEM, V126, P132, DOI 10.1016/j.marchem.2011.05.001 Burnett WC, 2006, SCI TOTAL ENVIRON, V367, P498, DOI 10.1016/j.scitotenv.2006.05.009 BUTTS J, 1988, MAR CHEM, V25, P349, DOI 10.1016/0304-4203(88)90115-6 Charette MA, 2012, LIMNOL OCEANOGR-METH, V10, P451, DOI 10.4319/lom.2012.10.451 Charette MA, 2001, LIMNOL OCEANOGR, V46, P465 Foster DA, 2004, MAR CHEM, V87, P59, DOI 10.1016/j.marchem.2004.02.003 Garcia-Solsona E, 2008, MAR CHEM, V109, P198, DOI 10.1016/j.marchem.2007.11.006 GIFFIN C, 1963, J GEOPHYS RES, V68, P1749, DOI 10.1029/JZ068i006p01749 Hsieh YT, 2011, J ANAL ATOM SPECTROM, V26, P1338, DOI 10.1039/c1ja10013k Ku TL, 2008, RADIOACTIV ENVIRONM, V13, P307, DOI 10.1016/S1569-4860(07)00009-5 KU TL, 1976, EARTH PLANET SC LETT, V32, P236, DOI 10.1016/0012-821X(76)90064-9 Moatar F, 2010, J RADIOANAL NUCL CH, V283, P3, DOI 10.1007/s10967-009-0001-2 Moore WS, 1996, J GEOPHYS RES-OCEANS, V101, P1321, DOI 10.1029/95JC03139 Moore WS, 2008, MAR CHEM, V109, P188, DOI 10.1016/j.marchem.2007.06.015 MOORE WS, 1995, GEOCHIM COSMOCHIM AC, V59, P4285, DOI 10.1016/0016-7037(95)00242-R Moore WS, 2003, BIOGEOCHEMISTRY, V66, P75, DOI 10.1023/B:BIOG.0000006065.77764.a0 Peterson RN, 2009, LIMNOL OCEANOGR-METH, V7, P196 Rama, 1996, GEOCHIM COSMOCHIM AC, V60, P4645 Rodellas V, 2012, J HYDROL, V466, P11, DOI 10.1016/j.jhydrol.2012.07.005 Sun Y, 1998, MAR CHEM, V62, P299, DOI 10.1016/S0304-4203(98)00019-X van Beek P, 2010, J ENVIRON RADIOACTIV, V101, P521, DOI 10.1016/j.jenvrad.2009.12.002 Waska H, 2008, J ENVIRON RADIOACTIV, V99, P1859, DOI 10.1016/j.jenvrad.2008.08.008 Geibert, Walter Rodellas, Valenti Annett, Amber van Beek, Pieter Garcia-Orellana, Jordi Hsieh, Yu-Te Masque, Pere Masque, Pere/B-7379-2008 Masque, Pere/0000-0002-1789-320X National Environmental Research Council through "UK Geotraces" [NE/H008497/1]; Scottish Alliance for GeoSciences and the Environment; MICINN (Spain) [AP2008-03044]; "Antarctic Science" research bursary, the British Antarctic Survey, NERC's Collaborative Gearing Scheme by the Natural Sciences and Engineering Research Council of Canada; "Antarctic Science" research bursary, the British Antarctic Survey, NERC's Collaborative Gearing Scheme by the University of Edinburgh; British Council-Egide "Alliance" scheme; prize ICREA Academia; Generalitat de Catalunya We would like to gratefully acknowledge support from funding agencies: W. G. and Y.-T. Hsieh from the National Environmental Research Council through "UK Geotraces" (NE/H008497/1); W. G. from the Scottish Alliance for GeoSciences and the Environment; V. R. for a PhD fellowship (AP2008-03044) from MICINN (Spain); A. A. from the "Antarctic Science" research bursary, the British Antarctic Survey, NERC's Collaborative Gearing Scheme, by the Natural Sciences and Engineering Research Council of Canada and by the University of Edinburgh; W. G., A. A., and P. v. B. received travel support from the British Council-Egide "Alliance" scheme; P. M. through the prize ICREA Academia, funded by the Generalitat de Catalunya. Thanks go to Gideon Henderson, Raja Ganeshram, and Michiel Rutgers van der Loeff; their contributions were essential to enable us to finish this manuscript. Three anonymous reviewers have provided helpful insights that contributed to improve the manuscript substantially. 0 AMER SOC LIMNOLOGY OCEANOGRAPHY WACO LIMNOL OCEANOGR-METH ; We present a new method to determine Ra-226 in aqueous environmental samples, based on the rate of ingrowth of Rn-222 from Ra-226, using the radium delayed coincidence counter (RaDeCC). We use the same instrument setup that is used for the determination of Ra-223 and Ra-224. In contrast to methods published earlier, the approach does not require a modification of the counting equipment, counting separately for Ra-226, or waiting for radioactive equilibrium. We show that the calibration works from as low as 10 dpm (0.166 Bq) per sample, up to more than 1000 dpm (16.7 Bq). Although uncertainties are larger (typically around 10%) than reported uncertainties for gamma counting, liquid scintillation, or mass spectrometry at comparable activities, the simple setup, low cost, and robustness of the method make it a useful approach for underway measurements, combinations with short-lived radium isotopes, or monitoring purposes when limited funding or infrastructure is available.