A protocol for quantifying mono- and polysaccharides in seawater and related saline matrices by electro-dialysis (ED) – combined with HPAEC-PAD

Abstract

Abstract. An optimized method is presented to determine dissolved free (DFCHO) and dissolved combined carbohydrates (DCCHO) in saline matrices, such as oceanic seawater, Arctic ice core samples or brine using a combination of a desalination with electro-dialysis (ED) and high-performance anion exchange chromatography coupled to pulsed amperometric detection (HPAEC-PAD). Free neutral sugars, such as glucose and galactose, were found with 95 %–98 % recovery rates. Free amino sugars and free uronic acids were strongly depleted during ED at pH=8, but an adjustment of the pH could result in higher recoveries (58 %–59 % for amino sugars at pH=11; 45 %–49 % for uronic acids at pH=1.5). The applicability of this method for the analysis of DCCHO was evaluated with standard solutions and seawater samples compared with another established desalination method using membrane dialysis. DFCHO in field samples from different regions on Earth ranged between 11 and 118 nM and DCCHO between 260 and 1410 nM. This novel method has the potential to contribute to a better understanding of biogeochemical processes in the oceans and sea–air transfer processes of organic matter into the atmosphere in future studies.

Leaching Material from Antarctic Seaweeds and Penguin Guano Affects Cloud-Relevant Aerosol Production

“…Given most SSA studies always take the Chl-a as referent organic material (Rinaldi et a., 2013), the original water (SW21, Chla 1.5 μg m −3 ) and the waters with the leached material (SW 22-25, Chl-a 1.5 ± 1 μg m −3 ) had the same order of magnitude. The average Chl-a concentration in seawater samples collected nearby were in the order of about 0.04-6 μg L −1 (Zeppenfeld et al, 2020), our laboratory experiments have Chl-a values in the order with the literature.…”

“…Dissolved free carbohydrates (DFCHO), dissolved combined carbohydrates (DCCHO, <0.2 μm) and particulate combined carbohydrates (PCCHO, >0.2 μm) were determined as described by Zeppenfeld et al (2020Zeppenfeld et al ( , 2021. For the analysis of DFCHO and DCCHO, a filtered subsample of 9 mL (0.2 μm Millex syringe filter) was desalinated by electro-dialysis.…”

Aerosol Marine Primary Carbohydrates and Atmospheric Transformation in the Western Antarctic Peninsula

“…Carbohydrates in Seawater and Aerosol Samples. DFCHO and DCCHO in filtered (0.2 μm Millex syringe filters) SML and bulk samples were quantified following the protocol described by Zeppenfeld et al 71 using high-performance anionexchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD) after a desalination step by electrodialysis. DCCHO were quantified as a difference between the For the analysis of carbohydrates in aerosol particles, onethird of the Berner foils were extracted in 5 mL of ultrapure water (resistivity = 18.2 MΩ cm).…”

Sea Ice Microbiota in the Antarctic Peninsula Modulates Cloud-Relevant Sea Spray Aerosol Production

“…Average Chl a concentration in the sea ice reached 9.0 ± 2.3 µg L -1 (Figure 1A) and was significantly higher than in seawater samples collected nearby (same PI-ICE field study, data collected within 100 km from the sea ice sampling point, Chl-a of about 0.03-2.2 µg L -1 , Zeppenfeld et al, 2020). These high values of Chl a concentration in the melted sea ice samples corresponded to the high microphytoplankton biomass living inside the sea icemeasured during previous studies (Arrigo et al, 2009;Arrigo, 2014).…”

“…Particulate combined carbohydrates (PCCHO, >0.2µm), dissolved combined carbohydrates (DCCHO, <0.2µm) and dissolved free carbohydrates (DFCHO) were determined as described by (Zeppenfeld et al, 2020;Zeppenfeld et al, 2021) using a high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). DFCHO, DCCHO and PCCHO were calculated as the sums of following monosaccharides, either occurring as free molecules (DFCHO) or being released after an acid hydrolysis (DCCHO & PCCHO): glucose, fucose, arabinose, rhamnose, galactose, xylose, mannose, fructose, glucosamine, galactosamine, muramic acid, glucuronic acid, galacturonic acid.…”