Sediment sample analysis

The other popular sequential extraction procedure is the protocol proposed by the Community Bureau of Reference, Commission of the European Community (known as the BCR protocol). The method was proposed on the basis of interlaboratory smdies undertaken in order to harmonize conditions for soil and sediment sample analysis. Based on the research data, in 1992 it was stated that application of EDTA or acetic acid solution is appropriate and sufficient for elimination of the bioaccessible fi action of metals from soil samples [62]. In the case of other samples, best results were achieved after application of a three-stage procedure with the following extractants ... 

Several chemical reactions, including calcium carbonate and hydroxyapatite precipitation, have been studied to determine their relationship to observed water column and sediment phosphorus contents in hard water regions of New York State. Three separate techniques have been used to Identify reactions important in the distribution of phosphorus between the water column and sediments 1) sediment sample analysis employing a variety of selective extraction procedures 2) chemical equilibrium calculations to determine ion activity products for mineral phases involved in phosphorus transport and 3) seeded calcium carbonate crystallization measurements in the presence and absence of phosphate ion. 

This somewhat lengthy experiment provides a thorough introduction to the use of GG for the analysis of trace-level environmental pollutants. Sediment samples are extracted by sonicating with 3 X 100-mL portions of 1 1 acetone hexane. The extracts are then filtered and concentrated before bringing to a final volume of 10 mL. Samples are analyzed with a capillary column using a stationary phase of 5% phenylmethyl silicone, a splitless injection, and an EGD detector. 

Figure 13.2 MDGC-ECD chromatograms of PCB fractions from sediment samples, demonstrating the separation of the enantiomers of (a) PCB 95, (b) PCB 132, and (c) PCB 149 non-labelled peaks were not identified. Reprinted from Journal of Chromatography, A 723, A. Glausch et al, Enantioselective analysis of chiral polyclilorinated biphenyls in sediment samples by multidimensional gas cliromatography-electi on-capture detection after steam distillation-solvent exti action and sulfur removal , pp. 399-404, copyright 1996, with permission from Elsevier Science.

Figure 15-12 is a schematic illustration of a technique known as acid volatile sulfides/ simultaneously extracted metals analysis (AVS/SEM). Briefly, a strong acid is added to a sediment sample to release the sediment-associated sulfides, acid volatile sulfides, which are analyzed by a cold-acid purge-and-trap technique (e.g., Allen et ai, 1993). The assumption shown in Fig. 15-12 is that the sulfides are present in the sediments in the form of either FeS or MeS (a metal sulfide). In a parallel analysis, metals simultaneously released with the sulfides (the simultaneously extracted metals) are also quantified, for example, by graphite furnace atomic absorption spectrometry. Metals released during the acid attack are considered to be associated with the phases operationally defined as "exchangeable," "carbonate," "Fe and Mn oxides," "FeS," and "MeS."... 

A maximum trichloroethylene level of 9.9 ppb was found in sediment from Liverpool Bay, England (Pearson and McConnell 1975). Sediment levels from nondetectable to 0.2 ppb (wet weight) trichloroethylene were found in Lake Pontchartrain near New Orleans (Ferrario et al. 1985). An analysis of the EPA STORET Data Base (1980-1982) found that trichloroethylene had been positively detected in sediment samples taken at 6% of 338 observation stations, with median levels of <5 pg/kg (dry weight) (<5 ppb) (Staples et al. 1985). The observation stations included both "ambient" and "pipe" sites. Ambient sites include streams, lakes, and ponds and are intended to be indicative of general U.S. waterway conditions. Pipe sites refer to municipal or industrial influents or effluents. 

Analysis of chlorobenzoates in sediments, which had been contaminated with PCBs, was used to demonstrate that the lower PCB congeners that had initially been produced by anaerobic dechlorination were subsequently degraded under aerobic conditions. The chlorobenzoates were transient metabolites and their concentrations were extremely low since bacteria that could successfully degrade them were present in the sediment samples (Elanagan and May 1993). 

ScHRON W, Liebmann A, Nimmereall G 2000) Direct solid sample analysis of sediment, soils, rocks and advanced ceramics by ETV-ICP-AES and GF-AAS. Fresenius J Anal Chem 366 79-88. 

An important consideration prior to sample collection is transportation and storage. Samples should be treated so as to retain the integrity of the sample from the moment of collection to the time of analysis. The physico-chemical characteristics of a sediment sample change during drying, with effects on the sorption-desorption behavior of chemicals. 

Organic solvents or mixtures of water and solvents such as acetone or water-acetone are commonly used to extract chemicals from sediment samples as for upland soil. An analysis of sediment, collected from waterways or extremely low Eh paddies, frequently requires the removal of sulfur-containing species, although there is little interference from sulfur if the sediments are in a not very reductive condition. Reduced copper and silver nitrate columns are usually used for the removal, but these procedures are not always successful. Recovery studies could be needed to confirm an interference with sulfur. 

Oxime carbamates are not directly amenable to gas chromatography (GC) because of their high thermal instability, which often leads to their breakdown at the injection port or in the column during analysis. Analysis of oxime carbamates by GC with sulfur detection or flame photometric detection involves oxidation of the intact insecticides or alkaline hydrolysis to form the more volatile but stable oxime compound. Enzymatic techniques have been reported for the analysis of these compounds. Enzyme-linked immunosorbent assay (ELISA) has been used to determine aldicarb and its sulfone and sulfoxide metabolites and methomyl in water, soil, and sediment samples. 

CutshallNH, Larsen IL, Olsen CR. 1983. Direct analysis of 210Pb in sediment samples Self absorption corrections. Nucl Instrum Methods 206 309. 

Mineral Oil Hydraulic Fluids. Methods are available for analysis of the hydrocarbon components of mineral oil hydraulic fluids (predominantly straight and branched chain alkanes) in environmental samples. Some of these methods are summarized in Table 6-3. In general, water and sediment samples are extracted with a suitable solvent in a Soxhlet extractor (for solid samples) or in separatory funnel or shake flask (for liquid samples) (Bates et al. 1984 Peterman et al. 1980). The extract is cleaned up on silica gel or Florisil columns using a nonpolar solvent to elute the nonpolar alkanes. Analysis is usually performed by GC/MS (Bates et al. 1984 Kawamura and Kaplan 1983 Peterman et al. 1980). Method performance has not been reported, although 82% recovery of aliphatic hydrocarbons was reported for rainwater (Kawamura and Kaplan 1983). 

Krishnamurty, K. V. et al., At. Abs. Newslett., 1976, 15, 68-70 When preparing soil and sediment samples for atomic absorption spectral analysis for trace metals, pre-oxidation with nitric acid before addition of hydrogen peroxide eliminates the danger of explosion. 

Pocklington and Hardstaff [432] react sediment samples with 1,3,5-tri-hydroxybenzene in alcoholic hydrochloric acid to produce a colour in the particulate lignins, facilitating their identification under the microscope. Samples high in lignins can then be subjected to the normal methods of analysis. This is an excellent screening technique (semi-quantitative). 

Bedload was sampled during competent flows at the same vertical than suspended sediment. Bedload analysis has been based upon 215 samples, 145 during 2002-2003 and 70 during 2003-2004. At SMS we used a 29-kg cable-suspended Helley-Smith sampler with a 76-mm intake and an expansion ratio (i.e. ratio of nozzle exit area to entrance area) of 3.22 (Fig. 2c). Bedload was measured at... 

A sample may be characterized by the determination of a number of different analytes. For example, a hydrocarbon mixture can be analysed by use of a series of UV absorption peaks. Alternatively, in a sediment sample a range of trace metals may be determined. Collectively, these data represent patterns characteristic of the samples, and similar samples will have similar patterns. Results may be compared by vectorial presentation of the variables, when the variables for similar samples will form clusters. Hence the term cluster analysis. Where only two variables are studied, clusters are readily recognized in a two-dimensional graphical presentation. For more complex systems with more variables, i.e. //, the clusters will be in -dimensional space. Principal component analysis (PCA) explores the interdependence of pairs of variables in order to reduce the number to certain principal components. A practical example could be drawn from the sediment analysis mentioned above. Trace metals are often attached to sediment particles by sorption on to the hydrous oxides of Al, Fe and Mn that are present. The Al content could be a principal component to which the other metal contents are related. Factor analysis is a more sophisticated form of principal component analysis. 

Demetriades, A. 2008. Overbank sediment sampling in Greece a contribution to the evaluation of methods for the Global Geochemical Baselines mapping project. Geochemistry Exploration, Environment, Analysis, 8, 229-240. 

The analysis of steroid sexual hormones and related synthetic compounds in WW, soil, sludge, and sediment samples is a challenging task. This is due to both the complex environmental matrices and the requirement of low detection limits. Therefore, the use of complicated, time- and labor-consuming analytical procedures is necessary. 

Mass spectrometers have been used at some level in all of these types of investigations because of their unsurpassed sensitivity and specificity, their multicomponent analytical capability and, in some cases, their ability to provide precise and accurate isotope ratios. Traditional methods of analysis typically involve the collection of water and sediment samples, or biological specimens, during field expeditions and cmises on research vessels (R/Vs), and subsequent delivery of samples to a shore-based laboratory for mass spectrometric analyses. The recent development of field-portable mass spectrometers, however, has greatly facilitated prompt shipboard analyses. Further adaptation of portable mass spectrometer technology has also led to construction of submersible instruments that can be deployed at depth for in situ measurements. 

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