A novel protocol for determining the concentration and composition of sugars in particulate and in high molecular weight dissolved organic matter (HMW-DOM) in seawater

Abstract

Please cite this article as: Engel, Anja, Händel, Nicole, A novel protocol for determining the concentration and composition of sugars in particulate and in high molecular weight dissolved organic matter (HMW-DOM) in seawater, Marine Chemistry (2011Chemistry ( ), doi: 10.1016Chemistry ( /j.marchem.2011 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Here, we show that desalting by membrane dialysis (1kDa) is an efficient alternative to ion exchange resins and yields recoveries of >90% for HMW carbohydrates. We conducted several tests to determine the accuracy and reproducibility of the method. Sugar concentrations determined with our protocol were compared to results obtained with the colorimetric TPTZ-method, and with earlier HPAEC-PAD protocols using cation/ anion exchange resins. Applications of our protocol to field samples indicated that acidic sugars can comprise a substantial fraction (30-50%) of HMW dissolved carbohydrates in seawater.The simultaneous analysis of the three classes of sugars appears promising to detect a larger fraction of marine combined carbohydrates, and thus to improve our understanding of organic matter cycling in the ocean.

Jellyfish biochemical composition: importance of standardised sample processing

“…Desalting by membrane dialysis is commonly used in bio chemistry when salt ions in the sample interfere with the analyses (e.g. Zhou et al 1998, Engel & Händel 2011 ) were determined in these water samples according to standard colorimetric methods (Grasshoff et al 1983) and their modifications (Grasshoff et al 1999). An empty dialyzing tube submerged in 200 ml of MilliQ water was used as control.…”

Size-fractionated dissolved primary production and carbohydrate composition of the coccolithophore <i>Emiliania huxleyi</i>

“…Total combined carbohydrates (tCCHO) and highmolecular-weight (HMW; > 1 kDa) dissolved combined carbohydrates (dCCHO) were determined by ion chromatography after Engel and Händel (2011). Duplicate samples for HMW-dCCHO were filtered through 0.45 µm syringe filters (GHP membrane, Acrodisk, Pall Corporation) and stored in combusted (8 h at 500 • C) glass vials at −20 • C. Samples for tCCHO remained unfiltered and were stored identically.…”

Variation in Colloidal Organic Matter Composition and Aggregation in Coastal Waters (Gulf of Trieste, Northern Adriatic Sea)

“…To isolate COM, the filtrates were ultrafiltered through a membrane with a nominal molecular weight cut-off (MWCO) of 5 kDa using six Vivascience Vivaflow 200 units (Sartorius) with three Masterflex S/L membrane pumps (Cole-Palmer) at a flow rate of 300 ml min ¡1 at 2.5 bar at 20 C. The average concentration factor (CF) was 65. Retentates were freeze-dried and afterwards desalted by dialysis (Engel and Handel 2011) in Milli-Q water for 18 h at 4 C using MWCO 1 kDa RC membranes (Spectrapor 7, Spectrum Lab). The surrounding milliQ water was exchanged twice after 2 and 4 h to reduce salinity from 37 psu to < 0.2 psu.…”