FN Archimer Export Format
PT J
TI Influence of the conservation mode of seawater for dissolved organic carbon analysis
BT 
AF Fourrier, Pierre
   Dulaquais, Gabriel
   Riso, Ricardo
AS 1:1;2:1;3:1;
FF 1:;2:;3:;
C1 Laboratoire des Sciences de l’Environnement Marin CNRS UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Nicolas Copernic, 29280, Plouzané, France
C2 UBO, FRANCE
UM LEMAR
IN WOS Cotutelle UMR
IF 3.3
TC 1
UR https://archimer.ifremer.fr/doc/00795/90746/105076.pdf
LA English
DT Article
CR TONGA 2019
BO L'Atalante
DE ;Dissolved organic carbon;Seawater analysis;DOM preservation;Size exclusion chromatography
AB Marine dissolved organic matter (DOM) is one of the largest exchangeable organic carbon reservoir on the planet. The main proxy to track the distribution of DOM in the aquatic environments remains dissolved organic carbon (DOC). Thereby the optimal protocol for long-term DOC preservation in seawater samples must be defined. In this context, we monitored bulk DOC concentrations and its size class distribution in filtered seawater samples during yearlong experiments. With different conservation mode, we tested two types of commonly used materials (borosilicate brown glass and high-density polyethylene, HDPE) and three conditioning protocols (untreated, acidified at pH 2 and frozen at −20 °C). Offshore samples collected along the entire water column of the Pacific Ocean and stored in HDPE bottles were also analysed after 2 years of storage at pH of 2 and compared to frozen samples. Results demonstrated that bulk DOC concentrations can be accurately determined in untreated samples for one month and for years in frozen samples as well as in acidified samples, when samples are stored in acid cleaned HDPE bottles or flame sealed glass ampoules. Storage in brown glass vials with Bakelite caps seems more uncertain. The study of the size class distribution of DOC reveals the possibility to study DOM for 1 month in filtered samples with no additional treatment and for years in frozen samples when stored in acid cleaned HDPE bottles. Significant changes in DOC size fractionation were observed when samples were acidified. The high molecular weight (HMW) compounds and the humic substances from the upper 1000 m were significantly degraded at pH 2, incorporating DOC in the low molecular weight (LMW) fractions. These experiments provide preservation guidelines for future studies that aim either to study bulk DOC or the chemical properties marine DOM. It is recommended to store seawater in HDPE vials at −20 °C for DOM study, or at pH 2 for bulk DOC measurements. 
PY 2022
PD NOV
SO Marine Environmental Research
SN 0141-1136
PU Elsevier BV
VL 181
UT 000863462600003
DI 10.1016/j.marenvres.2022.105754
ID 90746
ER

EF