Coulometric total carbon dioxide analysis for marine studies: Automation and calibration

Johnson, K.M.; Sieburth, John McN.; Williams, Peter; Brändström, L

doi:10.1016/0304-4203(87)90033-8

Cited by 309 publications

(161 citation statements)

References 8 publications

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“…The bottles were sealed with rubber stoppers and aluminium crimp-seal caps. DIC was measured by coulometric determination of extracted CO2 after Johnson et al (1987). Total alkalinity in each sample was determined by potentiometric titration with hydrochloric acid (0.1 M HC1 in 0.6 M NaC1) after Winn et al (1994) and calculated according to standard procedures described in DOE (1994).…”

Section: Methodsmentioning

confidence: 99%

Lake Kauhako-, Moloka'i, Hawai'i: biological and chemical aspects of a morpho-ectogenic meromictic lake

Donachie¹,

Kinzie²,

Bidigare³

et al. 1999

Aquat. Microb. Ecol.

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We undertook the first combined microbiological and hydrochemical study of the 248 m deep meromichc Lake KauhakG. Situated at sea level 1.6 km from the sea in the crater of an extinct volcano on the island of Moloka'i, Hawai'i, USA, Lake KauhakB has the highest relative depth (ratio of depth to surface area, z, = 374 %) of any lake in the world. The upper 4.5 m were stratified (T= 23 to 26'C, salinity = 6 to 24.5), but below a pycnocline at -4.5 m temperature and salinity were uniform (T = -26.25"C; salinity = 32). Seawater hkely intrudes by horizontal hydraulic conductivity through rock separating the lake and the Pacific Ocean. Anoxia commenced below 2 m. Hydrogen sulfide was undetectable at 4 m. but averaged -130 PM between 5 and 28 m. Dissolved inorganic carbon concentrations ranged from -1.50 mM at the surface to -3.3 mM below 5 m. Total organic carbon peaked at 0.94 mM above the pycnocline hut rernaiced about 0.30 mM be!ow 5 m. Soluble reactive phosphorus and ammunium concentrations, nanomolar above the pycnocline, increased to -28 and l75 PM, respectively, at greater depth. Nitrate attained 3.7 PM in shallow water, but was -0.2 pM from the pycnocline to 100 m. Leucine aminopeptidase (LAPase) activity at the surface exceeded 1100 nmol of substrate hydrolyzed I-' h-' Activities of a-and P-glucosidase were lower, but showed depth distributions similar to that of LAPase. Surface waters hosted large and diverse picoplankton populations; chlorophyll a (chl a) exceeded 150 1-19 I-'. and heterotrophic bacteria and autofluorescent bacteria attained 2 X log and 9 X 109 1-l, respectively. Filamentous cyanobacteria and 'Proch1orococcus'-like autotrophs occurred only in the upper 2 m. Chl a was the dominant pigment above 2 m, but pigment diversity increased markedly in anoxic waters between 3 and 5 m. Lake Kauhako is a unique habitat for further studies, particularly of interactions among flora and fauna restricted to a shallow water column within a single basin.

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Section: Methodsmentioning

confidence: 99%

Lake Kauhako-, Moloka'i, Hawai'i: biological and chemical aspects of a morpho-ectogenic meromictic lake

Donachie¹,

Kinzie²,

Bidigare³

et al. 1999

Aquat. Microb. Ecol.

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“…, NO 3 -, PO 4 3-, DSi). For DIC, 12 mL of subsample was stored in gastight Excitainers (Labco, UK) spiked with 200 lL saturated HgCl 2 until analysis on a coulometer (CM5012 UIC Coulometrics; precision ± 2 lmol L -1 ) (Johnson et al 1987). Samples for N 2 -Ar measurements were stored at 15°C in submerged 7-mL glass stoppered vials with 100 lL saturated HgCl 2 until analysis on membrane inlet mass spectrometer (Balzers QMS422; precision for N 2 determination ± 0.5 lmol L -1 ) (Eyre et al 2002).…”

Section: In Situ Chamber Incubationsmentioning

confidence: 99%

Benthic Carbon Mineralization and Nutrient Turnover in a Scottish Sea Loch: An Integrative In Situ Study

et al. 2016

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Based on in situ microprofiles, chamber incubations and eddy covariance measurements, we investigated the benthic carbon mineralization and nutrient regeneration in a *65-m-deep sedimentation basin of Loch Etive, UK. The sediment hosted a considerable amount of infauna that was dominated by the brittle star A. filiformis. The numerous burrows were intensively irrigated enhancing the benthic in situ O 2 uptake by *50 %, and inducing highly variable redox conditions and O 2 distribution in the surface sediment as also documented by complementary laboratory-based planar optode measurements. The average benthic O 2 exchange as derived by chamber incubations and the eddy covariance approach were similar (14.9 ± 2.5 and 13.1 ± 9.0 mmol m -2 day -1 ) providing confidence in the two measuring approaches. Moreover, the non-invasive eddy approach revealed a flow-dependent benthic O 2 flux that was partly ascribed to enhanced ventilation of infauna burrows during periods of elevated flow rates. The ratio in exchange rates of RCO 2 and O 2 was close to unity, confirming that the O 2 uptake was a good proxy for the benthic carbon mineralization in this setting. The infauna activity resulted in highly dynamic redox conditions that presumably facilitated an efficient degradation of both terrestrial and marine-derived organic material. The complex O 2 dynamics of the burrow environment also concurrently stimulated nitrification and coupled denitrification rates making the sediment an efficient sink for bioavailable nitrogen. Furthermore, bioturbation mediated a high efflux of dissolved phosphorus and silicate. The study documents a high spatial and temporal variation in benthic solute exchange with important implications for benthic turnover of organic carbon and nutrients. However, more long-term in situ investigations with like approaches are required to fully understand how environmental events and spatio-temporal variations interrelate to the overall biogeochemical functioning of coastal sediments.

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“…Select bottles were subsampled on deck for analyses of the different chemical parameters. The DIC analyses were performed with a coulometer connected to a Single Operator Multi-parameter Metabolic Analyzer, SOMMA (Johnson et al, 1987), following the procedures outlined in the Handbook of Analysis of Carbon Parameters in Seawater (DOE, 1994). The accuracy of the DIC analyses was estimated at 2 mmol kg À 1 , except for the AJAX cruise of 1983 that preceded the availability of certified reference materials to confirm accuracy.…”

Section: Description Of Cruises and Instrumental Analysesmentioning

confidence: 99%

Changes in deep-water CO2 concentrations over the last several decades determined from discrete pCO2measurements

Wanninkhof

Park

Takahashi

et al. 2013

Deep Sea Research Part I: Oceanographic Research Papers

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a b s t r a c tDetection and attribution of hydrographic and biogeochemical changes in the deep ocean are challenging due to the small magnitude of their signals and to limitations in the accuracy of available data. However, there are indications that anthropogenic and climate change signals are starting to manifest at depth. The deep ocean below 2000 m comprises about 50% of the total ocean volume, and changes in the deep ocean should be followed over time to accurately assess the partitioning of anthropogenic carbon dioxide (CO 2 ) between the ocean, terrestrial biosphere, and atmosphere. Here we determine the changes in the interior deep-water inorganic carbon content by a novel means that uses the partial pressure of CO 2 measured at 20 1C, pCO 2 (20), along three meridional transects in the Atlantic and Pacific oceans. These changes are measured on decadal time scales using observations from the World Ocean Circulation Experiment (WOCE)/World Hydrographic Program (WHP) of the 1980s and 1990s and the CLIVAR/CO 2 Repeat Hydrography Program of the past decade. The pCO 2 (20) values show a consistent increase in deep water over the time period. Changes in total dissolved inorganic carbon (DIC) content in the deep interior are not significant or consistent, as most of the signal is below the level of analytical uncertainty. Using an approximate relationship between pCO 2 (20) and DIC change, we infer DIC changes that are at the margin of detectability. However, when integrated on the basin scale, the increases range from 8-40% of the total specific water column changes over the past several decades. Patterns in chlorofluorocarbons (CFCs), along with output from an ocean model, suggest that the changes in pCO 2 (20) and DIC are of anthropogenic origin.Published by Elsevier Ltd.

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Coulometric total carbon dioxide analysis for marine studies: Automation and calibration

Cited by 309 publications

References 8 publications

Lake Kauhako-, Moloka'i, Hawai'i: biological and chemical aspects of a morpho-ectogenic meromictic lake

Lake Kauhako-, Moloka'i, Hawai'i: biological and chemical aspects of a morpho-ectogenic meromictic lake

Benthic Carbon Mineralization and Nutrient Turnover in a Scottish Sea Loch: An Integrative In Situ Study

Changes in deep-water CO2 concentrations over the last several decades determined from discrete pCO2measurements

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