TY - JOUR

T1 - Analysis of oxygen isotopes of inorganic phosphate (δ18Op) in freshwater

T2 - A detailed method description for obtaining oxygen isotopes of inorganic phosphate in environmental water samples

AU - Nisbeth, Catharina S.

AU - Tamburini, Federica

AU - Kidmose, Jacob

AU - Jessen, Søren

AU - O'Connell, David W.

N1 - Funding Information: The study was funded by the Geocenter Denmark-grant 6-2015 and a GSI Griffith award grant 2015-sc-027. The authors would also like to acknowledge the support of the IAEA CRP ?Multiple isotope fingerprints to identify sources and transport of agro-contaminants?. In addition, gratitude is extended to the technical staff of the Environmental Engineering Research laboratory in Trinity College Dublin, Ireland. Publisher Copyright: © 2022

PY - 2022/1

Y1 - 2022/1

N2 - The ability to identify the origin of phosphorus and understand processes controlling P cycling is essential for designing effective mitigation and restoration of eutrophic freshwater ecosystems. The oxygen isotope composition of orthophosphate (δ18Op) has significant potential as a tracer for P entering freshwater ecosystems. However, methods of analysis of δ18Op are still in their preliminary stages and have proven challenging to implement for new practitioners. In order to achieve progress in developing the application of δ18Op signatures as a tracing tool, there is a need to eliminate the methodological challenges involved in accurately determining δ18Op. This protocol article describes the various steps needed to concentrate and isolate orthophosphate in freshwater samples into an adequately pure Ag3PO4 analyte, without isotopic alteration during processing. The protocol compiles the disperse experiences from previous studies, combined with our own experience. The twofold aim of the paper is toprovide a baseline for an increasing standardisation of the silver phosphate purification method associated with analysis of the oxygen isotope composition of orthophosphate (δ18Op), and to foster new research in the applicability of δ18Op signatures for P source tracing in catchment science.

AB - The ability to identify the origin of phosphorus and understand processes controlling P cycling is essential for designing effective mitigation and restoration of eutrophic freshwater ecosystems. The oxygen isotope composition of orthophosphate (δ18Op) has significant potential as a tracer for P entering freshwater ecosystems. However, methods of analysis of δ18Op are still in their preliminary stages and have proven challenging to implement for new practitioners. In order to achieve progress in developing the application of δ18Op signatures as a tracing tool, there is a need to eliminate the methodological challenges involved in accurately determining δ18Op. This protocol article describes the various steps needed to concentrate and isolate orthophosphate in freshwater samples into an adequately pure Ag3PO4 analyte, without isotopic alteration during processing. The protocol compiles the disperse experiences from previous studies, combined with our own experience. The twofold aim of the paper is toprovide a baseline for an increasing standardisation of the silver phosphate purification method associated with analysis of the oxygen isotope composition of orthophosphate (δ18Op), and to foster new research in the applicability of δ18Op signatures for P source tracing in catchment science.

KW - Critical source areas

KW - Eutrophication

KW - Isotope tracing

KW - Nutrient biogeochemistry

KW - Phosphorus

KW - silver phosphate purification method association with analysis of the oxygen isotope composition of orthophosphate (δO)

KW - Water quality

U2 - 10.1016/j.mex.2022.101706

DO - 10.1016/j.mex.2022.101706

M3 - Journal article

C2 - 35518916

AN - SCOPUS:85129216779

VL - 9

JO - MethodsX

JF - MethodsX

SN - 2215-0161

M1 - 101706

ER -