Some trace elements in the waters,marine organisms and sediments of the Adriatic by neutron activation analysis

A number of investigations of trace elements in the waters, organisms and sediments of the Adriatic, using neutron activation analysis with radiochemical, separations are reported. These include studies of Hg in mussels from the Northern Adriatic, of Hg and Se in edible animals from the Rijeka region, and of seven elements (As, Cd, Cu, Hg, Mn, Se and Zn) in marine invertebrates from the Slovene coast. Additionally, plankton, sediment cores and water samples were taken from a grid of stations covering the whole Adriatic and analyzed for 6 to 11 of the trace elements As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Sb and Zn (Hg only in water). Generally, levels found were not indicative of pollution as compared with oceanic samples, but some evidence of locally increased levels was found, especially for Hg. The levels of eleven trace elements in three marine Intercomparison samples prepared by the IAEA Monaco Laboratory are also presented.     

Determination of inorganic and methylated arsenic species in marine organisms and sediments

The determination of inorganic arsenic, monomethylarsenic and dimethylarsenic in marine organisms and estuarine sediments is described. The arsenic species are isolated by solvent extraction, separated by ion-exchange chromatography and selectively determined by aisine generation. Recoveries of spikes of 5 and 10 μg of arsenic taken through the whole procedure were 92–96%. Typical results obtained in a study of the forms of arsenic in several species of macroalgae, tissues of Mercenaria mercenaria and estuarine sediments are given.     

The determination of chlorinated aliphatic hydrocarbons in air, natural waters, marine organisms, and sediments

A gas Chromatographic procedure is described for the determination of chlorinated aliphatic hydrocarbons in the atmosphere, natural waters, aquatic organisms and sediments. Air samples are passed through activated carbon traps and the chloro compounds are later desorbed by heating in a current of nitrogen. Chloro compounds are stripped from water samples by bubbling with nitrogen and from bio-materials and sediments by heating in a current of nitrogen. In each instance, the chlorinated compounds are trapped in copper columns packed with Chromosorb coated with silicone oil, and cooled to -78°. The chloro compounds are subsequently swept off these columns into a gas chromatographic column with a current of argon. Detection of the Chromatographic peaks is performed with an electron-capture detector. The procedure gives near quantitative recoveries of a range of chlorinated hydrocarbons from natural samples.     

A multivariate study of the programmed temperature vaporization injection-gas chromatographic-mass spectrometric determination of polycyclic aromatic hydrocarbons Application to marine sediments analysis

The trace analysis of polycyclic aromatic hydrocarbons (PAHs) in environmental matrices requires highly sensitive and selective methods. The use of large-volume injection in gas chromatography with mass spectrometry detection allows the improvement of the sensitivity. In this work, one of the most popular large-volume injectors, programmed temperature vaporization (PTV)-splitless injection, was optimized to determine 26 alkylated and non-alkylated PAHs at ultratrace levels. The injection conditions that use two different injection volumes, 10 and 25 μl, were optimized applying experimental designs. Six experimental factors that could affect the vaporization efficiency were studied. Detection limits for each assayed volume were compared with splitless injection, both in full scan and in SIM mode. An improvement of 50- and 100-fold, for 10 and 25 μl, respectively, was achieved for PAHs in comparison with splitless injection. Finally, the method that was optimized for 25 μl was applied successfully to the analysis of a certified marine sediment SRM 1941b and a real marine sediment extracted by microwave assisted extraction.     

超临界流体萃取及GC-MS对极地现代沉积物的分析

应用超临界萃取/气相色谱-质谱技术测定南极现代沉积物中的正构烷烃、甾烷、藿烷,其分析结果与经典索氏抽提基本相符.该方法所需样品量仅为索氏抽提的1/10,且高效、快速、无污染和危险,可用于少量特殊地质样品中生物标志化合物的萃取分析.     

Chromatographic analysis of hydrocarbons in marine sediments and seawater.

The low concentration of hydrocarbons anticipated in pollution baseline studies necessitates the development of analytical techniques sensitive at the sub-microgram per kilogram concentration level. The method of analysis developed in this laboratory involves dynamic headspace sampling for volatile hydrocarbon components of the sample, followed by coupled-column liquid chromatography for the non-volatile components. These techniques require minimal sample handling, reducing the risk of sample component loss and/or sample contamination. Volatile sample components are separated from the matrix in a closed system and concentrated on a TENAX-GC packed pre-column, free from large amounts of solvent and ready for GC/GC-MS analysis. Non-volatile compounds, such as the benzpyrenes, may be extracted from large volumes of water and concentrated on a Bondapak C18 packed pre-column for coupled-column liquid chromatographic separation and analysis. Results of the application of these techniques to the analysis of samples from sites of known low level hydrocarbon contamination are presented and discussed.     

Multi-residue analysis of polycyclic aromatic hydrocarbons, polychlorobiphenyls, and organochlorine pesticides in marine sediments

A multi-residue analysis procedure using microwave-assisted extraction and pre-purification has been developed for the combined analysis of polycyclic aromatic hydrocarbons (PAH), polychlorobiphenyls (PCB), and organochlorine pesticides (OCP) in marine sediments. This procedure has been validated with certified marine sediment. Several surrogate standards have been employed and the use of octachloronaphthalene (OCN) as a surrogate standard for organochlorine determination in this matrix is discussed. The recoveries of all compounds were high (>70%) and the relative standard deviations are of the same order as the certified values. Different analytical problems are discussed, including DDT degradation in gas chromatography and laboratory PCB background levels. Quantification problems encountered for two pesticides (cis-chlordane and trans-nonachlor) were attributed to PAH interference in the GC-ECD chromatogram.     

Gamma activation analysis of marine sediments at Havana Bay, Cuba

Summary Twenty six elements was studied preliminary in the superficial sediments of Havana Bay using gamma activation analysis by the electron accelerator microtron MT-25 at the Flerov Laboratory of Nuclear Reactions, JINR. Samples from five zones of Havana Bay including the three coves were analyzed. The obtained results show a close relation between the concentration levels of the studied elements and the pollution sources. Some elements (As, Ba, Ni, Pb, Cu, Zn, Fe, Cr, Mn) have high concentration levels compared to the values for other environmental marine sediments reported in the literature.     

Pyrethroids, pyrethrins, and piperonyl butoxide in sediments by high-resolution gas chromatography/high-resolution mass spectrometry

A new method for determination of pyrethroids, pyrethrins, and piperonyl butoxide (PBO) by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) was developed for aquatic sediments. The method detection limits for pyrethroids (15 compounds), pyrethrins, and PBO ranged from 0.16 to 1.50 ng/g sediment, which was suitable for detecting these chemicals at environmentally relevant concentrations (low ng/L range) that are toxicologically significant to benthic organisms. Recovery of the analytes from a low level spiked sediment ranged from 89.7% to 135%. Resmethrin showed the lowest recovery at 23.5% and pyrethrins showed the highest recovery at 154%. To confirm the utility of this new method for environmental applications, sediment samples collected from five tributaries of the San Francisco Bay, California were analyzed. Individual pyrethroids were detected in concentrations of up to 17.6 ng/g, while PBO was detected in all sediment samples in concentrations of 0.010-0.215 ng/g. Pyrethrins were not found in the sediment samples.     

Determination of trace elements in marine organisms by neutron activation analysis

The content of Na, Sc, Cr, Fe, Co, Zn, As, Br, Sb, Cs, La, Ce, Sm, Eu, Lu and Hf inEunicella cavolinii, Cladocoro cespitosa, Cystoseira barbata, Zostera marina, Posidonia oceanica andUlva lactuca was found to be approximately 3–5 orders of magnitude higher than reported for sea water, as determined by nondestructive neutron activation analysis (NNAA). The relative amounts of these elements in all organisms investigated are very similar and reflect their ratio in the media. Rare earth elements, however, are an exception and their accumulation appears to be specific. Among the organisms investigated,Zostera marina has the highest capacity for accumulation of most elements determined and thus may be used as an “indicator” organisms.     

Accuracy and precision in instrumental neutron activation analysis of reference materials and lake sediments

The k₀-standardization method applied in instrumental neutron activation analysis depends on experimental parameters such as the calibration of the detector and the metrology of the irradiation position. The related systematic errors are evaluated; Student's t-test is applied to results obtained for reference materials by the k₀-method. Precision is estimated for the reference materials and routine lake sediments by a method suggested by Minkkinen based on duplicate measurements.     

The determination of selenium in sea water,silicates and marine organisms

Spectrophotometric procedures are described for the determination of selenium in sea water, silicates (especially marine sediments) and marine organisms. Coprecipitation with iron(III) hydroxide at pH 4–6 is used to concentrate selenium and to separate it from many of the commoner elements. Separation from iron and other cations is achieved by ion exchange. Selenium is determined photometrically with diaminobenzidine. Isotope dilution with selenium-75 is used to correct results for the small losses occurring during the analysis. Silicates can be decomposed without loss of selenium by means of a mixture of hydrofluoric and nitric acids. The method of Cummins et al., with sulphuric and perchloric acids in presence of molybdate ion, is highly satisfactory for the decomposition of bio-materials. For sea water, which contains ca. 0.4–0.5 <mg Se/l, a standard deviation of 0.03 μg/l was obtained. A silicate sediment and a sea weed containing ca. 1.5 μg Se/g and 0.8 μg Se/g respectively gave coefficients of variation of 8.0% and 4.7%. The U.S. Geological Survey standard granite G1 was found to contain 2.5 ± 0.1 μg Se/g.     

Chemical composition of marine sediments in the Pacific Ocean from Sinaloa to Jalisco, Mexico

Marine sediments from Mexico’s West coast in the Pacific Ocean from Sinaloa to Jalisco were analyzed by energy-dispersive X-ray fluorescence technique. Ten sediment samples were collected in May, 2010 between 55.5 and 1264 m water depth with a Reinneck type box nucleate sampler. Sediments were dried and fractioned by granulometry. Their physical and chemical properties were determined in laboratory by standard methods, pH, and conductivity. Concentration and distribution of K, Ca, Ti Mn, Fe, Cu, Zn, Ga, Pb, Br and Sr were analyzed. In order to determine the status of the elements, enrichment factors were calculated. Total, organic carbon and CaCO₃ were also determined. Scanning electron microscopy and X-ray diffraction show predominant groups of compounds. As quality-control method, Certified Reference Material was both processed and analyzed at even conditions. Enrichment factors for K, Ca, Ti, Mn Fe, Cu, Zn, Ga, Ni, and Sr show they are conservative elements having concentrations in the range of unpolluted sites giving a base data line for the sampling zone In spite of moderately enrichment factors <100 μm size and bulk fractions, first Pb concentration fraction was similar to those found in not influenced by anthropogenic activities sites nearby Mazatlan Harbor. Bulk fraction concentration (52–133 μg g^?1) and enrichment factor show the influence of anthropogenic sources with values between lowest effect level and a third part of 250 μg g^?1value, which is considered to have severe effect levels for aquatic life.     

Instrumental neutron activation analysis results in an intercomparison campaign on lake and river sediments

Thirty-three elements were determined by instrumental neutron activation analysis in river and lake sediments, during an intercomparison campaign organized by the Italian Association of Oceanology and Limnology. The precision of the method is almost always better than 20%, while its accuracy, tested analyzing an NBS standard reference material, is about 10%. Interferences and possible errors are discussed.     

Some biological factors related to the 137Cs concentration of marine organisms

Marine Ecology Research Institute has been studying the factors controlling the concentration of radionuclides in marine biota. Weight of fish seemed to be an important factor controlling the concentration of ¹³⁷Cs because of the good correlation observed between the weight and the concentration of ¹³⁷Cs. Food habits also seemed to be an important factor because fishes in higher trophic levels tended to indicate higher concentration factors and a positive correlation was observed between the concentrations of predator fishes and those of the foodstuff. Gender could be another factor controlling the concentration of ¹³⁷Cs because the difference of ¹³⁷Cs between gender was observed in rockfish and marbled sole.     

Radioisotopes of thirteen elements in intertidal coastal and estuarine sediments in the Irish Sea

A survey has been carried out of⁴⁰K,⁶⁰Co,⁹⁹Tc,¹⁰⁶Ru,¹²⁵Sb,¹²⁹I,¹³⁴Cs,¹³⁷Cs,¹⁵⁴Eu,²²⁶Ra,²²⁸Ra,²³⁷Np,²³⁸Pu,^239,240Pu,²⁴¹Pu,²⁴¹Am,²⁴²Cm, and^243,244Cm activities in sediments from the Irish Sea. Several of these radionuclides were measured independently at two separate laboratories to enable the intercomparison of the results produced. The comprehensive data set generated allows the present spatial distributions of these radionuclides in coastal sediments to be examined in relation to sediment textural characteristics and by comparison with earlier survey, enables the temporal trends in their activities to be determined. In general all artificial radionuclides showed lower activities in sediments in response to falling discharges from Sellafield and relationships with either grain size, distance from Sellafield or both. Isotope ratios were similar to cumulative weighted activity ratios rather than present day values due to sediment mixing. Pu levels supplied evidence for the lag in response of sediment deposits with increasing distance from Sellafield due to sediment transport.     

Application of acetylacetone chelation solid-phase extraction to GFAAS measurements of trace amounts of beryllium in marine organisms.

Trace amounts of Be (0.046-2.59 ng) in a dried marine organism sample (10 mg) could be accurately determined by GFAAS after treating with microwave digestion (HNO3/H2O2) at 85 degrees C for 10 min and using acetylacetone as a chelating agent in the presence of an acetate buffer (pH 6.0). The method detection limit (MDL, 3sigma) for Be was found to be 4.6 ng g(-1); the calibration graph was linear up to 259 ng g(-1). Good recoveries (98.5-105.0%) were obtained for eight marine organism samples (including five fish, one lobster, one oyster, and one algae) with a relative standard deviation (RSD, n = 3) < 3.0%. The proposed method could be applied measurements of Be in various marine organisms.