Automated quantitative and isotopic (13C) analysis of dissolved inorganic carbon and dissolved organic carbon in continuous-flow using a total organic carbon analyser

There have been a number of studies that have attempted to estimate the past radiocarbon reservoir effects in Qinghai Lake, China. This article reports on measurements on modern samples collected at the lake in October 2003 and October 2009, which allow us to better understand the systematics of the lake and shed new insights on the processes occurring in the lake. The results indicate that atmospheric exchange of 14C is the main process affecting surface dissolved inorganic carbon (DIC) in the lake, but dissolved organic carbon (DOC) can be explained as a combination of sources. We also conclude that sediment carbon can be explained by a model where input from the surrounding rivers and groundwater are important, in agreement with the model of Yu et al. (2007).

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Using liquid chromatography-isotope ratio mass spectrometry to measure the δ13 C of dissolved inorganic carbon photochemically produced from dissolved organic carbon

Limnology and Oceanography Methods ◽

10.1002/lom3.10146 ◽

2016 ◽

Vol 15 (1) ◽

pp. 103-115 ◽

Cited By ~ 3

Author(s):

Leanne C. Powers ◽

Jay A. Brandes ◽

William L. Miller ◽

Aron Stubbins

Keyword(s):

Mass Spectrometry ◽

Liquid Chromatography ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Isotope Ratio ◽

Inorganic Carbon ◽

Dissolved Inorganic Carbon ◽

Isotope Ratio Mass Spectrometry

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Sebaran kandungan CO2 terlarut di perairan pesisir selatan Kepulauan Natuna

DEPIK ◽

10.13170/depik.3.2.1538 ◽

2014 ◽

Vol 3 (2) ◽

Author(s):

August Daulat ◽

Mariska Astrid Kusumaningtyas ◽

Rizki Anggoro Adi ◽

Widodo Setiyo Pranowo

Keyword(s):

Water Quality ◽

Organic Carbon ◽

Total Organic Carbon ◽

Coastal Waters ◽

Inorganic Carbon ◽

Dissolved Inorganic Carbon ◽

Good Condition ◽

Biogeochemical Cycles ◽

Silty Sand ◽

Organic Carbon Storage

Abstract. Biogeochemical cycles in coastal ecosystem is influencing the water quality and it is further affect on productivity and sustainability of coastal waters. Carbondioxide is one of the important parameter in biogeochemical cycles in coastal waters, it is formed as DIC (Dissolved Inorganic Carbon) in water and TOC (Total Organic Carbon) in sediment. The purpose of this research was to determine the distribution concentration of dissolved CO2 in the southern coastal waters of Natuna Islands. Insitu measurement was conducted for some parameters of water qualities both physical (i.e. temperature and turbidity) and chemical (i.e. DO, pH and salinity) parameters. DIC was analyzed in LIPI laboratory using Giggenbach titration method, while TOC in sediment was analyzed in Proling Laboratory, Institut Pertanian Bogor. The water quality of the southern coastal waters of Natuna Islands generally in a good condition according to the Ministry of Environment Decree, Number 51, year 2004. The results showed that spacial distribution of DIC ranged from 1.9 to 2.3 mol/kg, while TOC content of the water was ranged from 0.25 g/kg to 1.19 g/kg. Sediment distributions were dominated by sandy, silty sand, sandy silt and coral reefs, therefore the sediment has potencial as organic carbon storage and indicates a good productivity.Keywords: Carbondioxide; Dissolved Inorganic Carbon; Total Organic Carbon; Natuna Islands Abstrak. Siklus biogeokimia yang terjadi pada ekosistem pesisir dapat mempengaruhi kualitas perairan dan berfungsi sebagai penunjang keberlanjutan dan kesuburan perairan. Karbondioksida adalah salah satu parameter penting dalam siklus biogeokimia di perairan pesisir baik berupa DIC (Dissolved Inorganic Carbon) di dalam air maupun berupa TOC (Total Organic Carbon) di dalam sedimen. Penelitian ini bertujuan untuk mengetahui sebaran kandungan CO2 terlarut di perairan pesisir selatan Kepulauan Natuna. Pengukuran insitu dilakukan terhadap beberapa parameter kualitas air baik fisika (temperatur dan kecerahan) maupun kimia (DO, pH dan salinitas). Metode titrasi Giggenbach digunakan untuk analisis DIC di laboratorium LIPI, sedangkan TOC dalam sedimen dianalisis di laboratorium Proling, IPB. Kualitias air di perairan pesisir selatan Kepulauan Natuna secara umum masih berada dalam kondisi baik berdasarkan Keputusan Menteri Negara Lingkungan Hidup No. 51 tahun 2004. Hasil penelitian menunjukan sebaran spasial parameter kandungan CO2 dengan kandungan DIC berkisar antara 1,9-2,3 mol/kg, sedangkan kandungan TOC perairan berkisar antara 0,25-1,19 g/kg. Sebaran sedimen didominasi oleh pasir, pasir lanau, lanau pasiran dan terumbu karang yang berpotensi besar menyimpan karbon organik didalam sedimennya dan mengindikasikan kesuburan perairan pesisir selatan Kepulauan Natuna tergolong baik.

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Degradation of permafrost carbon in the Kolyma River

10.5194/egusphere-egu2020-8311 ◽

2020 ◽

Author(s):

Kirsi Keskitalo ◽

Lisa Bröder ◽

Dirk Jong ◽

Nikita Zimov ◽

Anya Davydova ◽

...

Keyword(s):

Organic Carbon ◽

Dissolved Organic Carbon ◽

Inorganic Carbon ◽

Dissolved Inorganic Carbon ◽

Climate Impacts ◽

Frozen Ground ◽

River Bank ◽

Permafrost Thaw ◽

Degradation Rates ◽

Kolyma River

Soil temperatures in permafrost (i.e. perennially frozen ground) are rising globally. The increasing temperatures accelerate permafrost thaw and release of organic carbon, that has been locked in permafrost soils since the last glacial period, to the contemporary carbon cycle. The potential remineralisation of organic carbon to greenhouse gases can contribute to further climate warming. Particulate organic carbon (POC) in the Kolyma River is older than dissolved organic carbon (DOC) thus serves as a good tracer for abrupt permafrost thaw (i.e. river bank erosion and thermokarst) that dominantly releases old POC. While dissolved organic carbon (DOC) mobilised from the old Yedoma outcrops on the banks of the Kolyma River is shown to be highly labile, vulnerability of POC to biodegradation is not yet known. In this study we aim to constrain degradation rates for POC in the Kolyma River. To capture seasonal variability of the POC pool and its degradation rate the incubation was conducted both during the spring freshet and in late summer (2019 and 2018, respectively). We incubated whole-water samples over 9 to 15 days and quantified POC (and DOC) loss over time, as well as dissolved inorganic carbon (DIC). The incubation was carried out in the dark. We also tracked changes in POC composition and age with carbon isotopes (d13C-OC, d13C-DIC, &#8710;14C). Preliminary results from 2018 suggest a decrease in POC concentrations of up to 30 % while those of DOC decrease by up to 11 %. The rate of POC degradation is nearly three times faster than DOC though the absolute amounts of DOC are in turn higher than those of POC (< 1 mg L-1 for POC and ~3 mg L-1 for DOC). Furthermore, the changes in d13C of POC, DOC and DIC suggest ongoing microbial degradation and conversion of organic carbon into inorganic carbon. These first estimates show that POC degrades fairly rapidly while transported in the Kolyma River. A better understanding of POC degradation along lateral flow paths is critical for improving our knowledge of permafrost thaw and its possible climate impacts in the future.

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