Showing papers in "Marine Chemistry in 1998"

TL;DR: In this article, a modified version of the ammonia diffusion method is used to measure 15 N −NH4+ in marine, estuarine and fresh waters. But, the method is not applicable to all types of water and it allows measurements with lower ammonium concentrations than has previously been possible.

TL;DR: In this paper, the C/N and stable C and N isotope ratios (delta(13)C, delta(15)N) of sedimentary and suspended particulate matter were determined in the Schelde Estuary.

TL;DR: In this paper, the authors analyzed the surface alkalinity of the major ocean basins using these measurements as well as those obtained during the GEOSECS and TTO studies.

TL;DR: For example, this article showed that sedimentary organic C (Corg) of both terrestrial and marine origin is efficiently decomposed in deltaic areas, with decomposition percentages reaching ≥70% and ≥90%, respectively, the latter percentage (marine) being quite comparable to deep-sea, low sedimentation environments.

TL;DR: Observations indicate that phytoplankton extracellular releases could be a major source of the dissolved heteropolysaccharides observed throughout the surface ocean.

TL;DR: Experimental data obtained from the Algero-Provencal basin (Western Mediterranean) in 1994 illustrates the homogeneity of phosphate, nitrate and silicate concentrations in deep-water throughout this basin, comparable to temperature and salinity homogeneity as mentioned in this paper.

TL;DR: For example, during a cruise in the sub-polar North Atlantic (50-70°N) in August 1993, a large fraction of the surface waters was elemental Hg (Hg°; 88% of the reactive Hg, on average; 0.65±0.50 pM) as discussed by the authors.

TL;DR: In this article, the UV excitation and emission spectra of cultures of marine bacteria and phytoplankton were investigated and the intensity of the emission band at 340 nm wavelength (λex=230 nm) was compared with cell number and protein content, and specific efficiencies were derived.

TL;DR: DeMaster et al. as mentioned in this paper conducted an interlaboratory comparison to assess the variability in the measurement of biogenic silica (BSi) in sediments among aquatic scientists.

TL;DR: In this article, the chemical speciation of dissolved Cu, Zn, Cd, and Pb was determined by differential pulse anodic stripping voltammetry (DPASV) at three sampling sites in the high salinity region (24-30 psu) of the Narragansett Bay estuary.

TL;DR: This paper used a combination of physical and chemical separation schemes to better characterize organic molecules complexing Cu, Zn, Cd, and Pb in Narragansett Bay, RI.

TL;DR: In this article, a shipboard simultaneous determination of dissolved organic carbon and total dissolved nitrogen in seawater by high temperature catalytic oxidation was performed by using a nitrogen-specific Antek 705D chemiluminescence detector and a CO 2 -specific LiCor Li6252 IRGA with a Shimadzu TOC-5000 organic carbon analyser.

TL;DR: In this paper, the authors measured dissolved organic carbon (DOC), nitrogen, amino acids, carbohydrates and inorganic nutrients on samples taken in July 1994 at 18 stations between Yakutsk and the Lena delta, East Siberia.

TL;DR: In this paper, the molecular weight distribution of dissolved organic carbon (DOC) in pore waters from estuarine and continental margin sediments was examined using ultrafiltration techniques and it was found that the majority of the pore water DOC (∼60-90%) had a molecular weight less than 3 kDa.

TL;DR: In this article, competitive ligand equilibration-cathodic stripping voltammetry (CLE-CSV) was used to study Fe speciation and the kinetic interaction of Fe 3+ with excess organic ligands in seawater.

TL;DR: Gledhill, M., Van den Berg, C.M.G., 1995. The role of organic complexation on ambient iron chemistry in the equatorial Pacific Ocean and the response of a mesoscale iron addition experiment was determined by a new competitive ligand equilibration/adsorptive cathodic stripping voltammetry method.

TL;DR: Rama et al. as mentioned in this paper studied the effects of precipitated NaCl and water content on the emanation characteristics of 220 Rn from the 224 Ra adsorbed on Mn-coated fiber.

TL;DR: In this article, the authors conducted a baseline study of contaminants in the North Atlantic Ocean, involving trace organics and trace elements, and determined the concentrations of 23 individual chlorobiphenyls (CBs) and 6 polyaromatic hydrocarbons (PAHs).

TL;DR: A chronology for the accumulation of a salt marsh core taken in the Venice Lagoon has been obtained from the activity-depth profile of excess 210 Pb, a naturally occurring radionuclide supplied to the marsh from the atmosphere.

TL;DR: Scaling the observed production rates using global standing stock estimates for Chl a and particulate nitrogen indicate that phytoplankton can account for only a fraction of the CH3Cl and CH3Br believed to be produced in the ocean.

TL;DR: A comparison of analyses of total carbon, nitrogen and organic carbon in a single sample of marine sediment and a pooled sample of settling particulate material collected by sediment trap was conducted by Wefer et al. as mentioned in this paper.

TL;DR: In this article, the authors used a fully automated instrument installed on a merchant ship to measure the partial pressure of carbon dioxide (P CO2 ) in the ocean surface and overlying atmosphere.

TL;DR: In this article, the concentrations and speciation of antimony, arsenic and selenium were determined in horizontal transects and eight vertical profiles in the North Atlantic Ocean between 54°N to 68°N as a part of the 1993 IOC Contaminant Baseline Survey.

TL;DR: In this article, the surface ocean dissolved inorganic carbon (DIC) and titration alkalinity have been measured for 7 years as a part of the Hawaii Ocean Time-series (HOT) program.

TL;DR: In this article, the influence of dimethylsulfide (DMS) and DOC concentrations and varying irradiance levels on the photolysis of DMS was evaluated with 0.2 μm filtered aged seawater from the northern Adriatic Sea and artificial radiation.

TL;DR: In this article, the authors investigated the speciation of iron in the northern North Sea using a combination of voltammetry techniques, using at least two different water masses and an algal bloom to measure the concentrations of reactive iron and total iron in unfiltered samples.

TL;DR: The diurnal variation of a number of naturally produced volatile halogenated organic compounds (VHOC) in a pool at Gran Canaria, Spain, is shown in this paper.

TL;DR: An analytical scheme for the determination of dissolved organic I, DOI, in marine waters has been designed in this paper, where the concentration of total I is determined as IO 3 − or I − after DOI has been oxidized to Io 3 − quantitatively by UV irradiation and all the inorganic I formed and present initially in the sample have been converted to the appropriate form for detection.

TL;DR: In this paper, the authors present a detailed analysis of Hg0 in surface waters and atmosphere of the Scheldt estuary and the North Sea and their relationship with biological processes.

TL;DR: In this article, a time-series of geochemical measurements was initiated along a 32 km transect across the inner continental shelf, off New Jersey, and the calculated fugacity of surface water carbon dioxide (fCO2) between April 1994 and April 1996 ranged from 211 to 658 μatm.