Determination of carbonate carbon in geological materials by coulometric titration

Engleman, E.E.; Jackson, Larry L.; Norton, Daniel R.

doi:10.1016/0009-2541(85)90025-7

Cited by 238 publications

(112 citation statements)

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“…Splits of selected samples were analyzed for concentrations of total carbon (TC) by coulometric titration of CO 2 extracted from the sediment by combustion at 950 C (Engleman et al 1985). Thirty-four samples were analyzed for inorganic carbon by acidification, and all had <0.01% inorganic carbon by weight, confirming the lack of carbonate minerals in Upper Klamath Lake sediments.…”

Section: Methodsmentioning

confidence: 98%

Limnological and Climatic Environments at Upper Klamath Lake, Oregon during the past 45 000 years

Bradbury

Colman

Dean

2004

Journal of Paleolimnology

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Upper Klamath Lake, in south-central Oregon, contains long sediment records with well-preserved diatoms and lithological variations that reflect climate-induced limnological changes. These sediment archives complement and extend high resolution terrestrial records along a north-south transect that includes areas influenced by the Aleutian Low and Subtropical High, which control both marine and continental climates in the western United States. The longest and oldest core collected in this study came from the southwest margin of the lake at Caledonia Marsh, and was dated by radiocarbon and tephrochronology to an age of about 45 ka. Paleolimnological interpretations of this core, based upon geochemical and diatom analyses, have been augmented by data from a short core collected from open water environments at nearby Howards Bay and from a 9-m core extending to 15 ka raised from the center of the northwestern part of Upper Klamath Lake. Pre-and full-glacial intervals of the Caledonia Marsh core are characterized and dominated by lithic detrital material. Planktic diatom taxa characteristic of cold-water habitats (Aulacoseira subarctica and A. islandica) alternate with warm-water planktic diatoms (A. ambigua) between 45 and 23 ka, documenting climate changes at millennial scales during oxygen isotope stage (OIS) 3. The full-glacial interval contains mostly cold-water planktic, benthic, and reworked Pliocene lacustrine diatoms (from the surrounding Yonna Formation) that document shallow water conditions in a cold, windy environment. After 15 ka, diatom productivity increased. Organic carbon and biogenic silica became significant sediment components and diatoms that live in the lake today, indicative of warm, eutrophic water, became prominent. Lake levels fell during the mid-Holocene and marsh environments extended over the core site. This interval is characterized by high levels of organic carbon from emergent aquatic vegetation (Scirpus) and by the Mazama ash (7.55 ka), generated by the eruption that created nearby Crater Lake. For a brief time the ash increased the salinity of Upper Klamath Lake. High concentrations of molybdenum, arsenic, and vanadium indicate that Caledonia Marsh was anoxic from about 7 to 5 ka. After the mid-Holocene, shallow, but open-water environments returned to the core site. The sediments became dominated (>80%) by biogenic silica. The open-water cores show analogous but less extreme limnological and climatic changes more typical of mid-lake environments. Millennial-scale lake and climate changes during OIS 3 at Upper Klamath Lake contrast with a similar record of variation at Owens Lake, about 750 km south. When Upper Klamath Lake experienced cold-climate episodes during OIS 3, Owens Lake had warm but wet episodes; the w This is the fourth in a series of eight papers published in this special issue, resulting from paleoenvironmental studies in the Upper Klamath Lake Basin. These studies were conducted by the US Geological Survey and its collaborators as part of a research effort c...

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Section: Methodsmentioning

confidence: 98%

Limnological and Climatic Environments at Upper Klamath Lake, Oregon during the past 45 000 years

Bradbury

Colman

Dean

2004

Journal of Paleolimnology

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“…The results were converted to concentration values of electromagnetic units (emu/cm3). Total carbon (C) was measured by combusting untreated samples of dried and crushed sediment at 960 • C (Engleman et al, 1985). The CO 2 released during this process was measured by titration in a coulometer cell.…”

Section: Methodsmentioning

confidence: 99%

Evidence for Millennial-Scale Climate Change During Marine Isotope Stages 2 and 3 at Little Lake, Western Oregon, U.S.A.

2001

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Pollen and geochemical data from Little Lake, western Oregon, suggest several patterns of millennial-scale environmental change during marine isotope stage (MIS) 2 (14,100-27,600 cal yr B.P.) and the latter part of MIS 3 (27,600-42,500 cal yr B.P.). During MIS 3, a series of transitions between warm-and cold-adapted taxa indicate that temperatures oscillated by ca. 2 • -4 • C every 1000-3000 yr. Highs and lows in summer insolation during MIS 3 are generally associated with the warmest and coldest intervals. Warm periods at Little Lake correlate with warm sea-surface temperatures in the Santa Barbara Basin. Changes in the strength of the subtropical high and the jet stream may account for synchronous changes at the two sites. During MIS 2, shifts between mesic and xeric subalpine forests suggest changes in precipitation every 1000-3000 yr. Increases in Tsuga heterophylla pollen at 25,000 and 22,000 cal yr B.P. imply brief warmings. Minimum summer insolation and maximum global ice-volumes during MIS 2 correspond to cold and dry conditions. Fluctuations in precipitation at Little Lake do not correlate with changes in the Santa Barbara Basin and may be explained by variations in the strength of the glacial anticyclone and the position of the jet stream. C 2001 University of Washington.

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“…The carbonate content was determined by a coulometric titration method [6]. X-ray diffraction (XRD) was used to confirm the apatitic structure of the powders as described in [12].…”

Section: Pii~sico-clii~iiiicrrl Cliurcicti~rtcrtioii Of the Apatite mentioning

confidence: 99%

Interactions of cisplatin with calcium phosphate nanoparticles: In vitro controlled adsorption and release

Barroug

Kuhn

Gerstenfeld

et al. 2004

Journal Orthopaedic Research

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A new system for the local delivery of chemotherapy to malignant solid tumors has been developed based on calcium phosphate (Cap) nanoparticles. The adsorption of the anti-neoplastic drug cis-diamminedichloroplatinum (cisplatin) was characterized on three types of apatitic CaP (poorly and well crystallized hydroxyapatite, and carbonated apatite). Adsorption isotherms obtained in chloride-free phosphate solutions at pH = 7.4 (24 and 37 "C) indicate that cisplatin adsorption increases with temperature and increases with decreasing crystallinity. Release studies in phosphate buffer saline (containing the chloride ion essential for release)showed that while the cumulative amount of released drug was the same for all apatites at 20 days (-70'%1 of the total bound), the least crystalline material released the drug more slowly. The drug release rate increased slightly with temperature. Cytotoxicity testing was conducted in a K8 clonal murine osteosarcoma cell line to verify that drug activity was retained after adsorption onto the apatite crystals. K8 cells were plated onto dried films of the apatitekisplatin conjugates and after 24 h, viability was measured with tritiated uridine. The apatitekisplatin formulations exhibited cytotoxic effects with a dose dependent diminishment of cell viability.

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Determination of carbonate carbon in geological materials by coulometric titration

Cited by 238 publications

References 4 publications

Limnological and Climatic Environments at Upper Klamath Lake, Oregon during the past 45 000 years

Limnological and Climatic Environments at Upper Klamath Lake, Oregon during the past 45 000 years

Evidence for Millennial-Scale Climate Change During Marine Isotope Stages 2 and 3 at Little Lake, Western Oregon, U.S.A.

Interactions of cisplatin with calcium phosphate nanoparticles: In vitro controlled adsorption and release

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