Preparation of Soil Samples

The preparation of undisturbed soil samples for laboratory testing can be considered in three separate cases. These cases are as follows (1) case I—the sample has enough strength to support itself during the trimming operation and subsequent transport to the testing 

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Mason, B. J. Preparation of Soil Sampling Protocol Techniques and Strategies, Report EPA-60014-83-020, U.S. Environmental Protection Agency, 1983. 

Brown and Reinsch [15] have discussed the collection and preparation of soil samples for the US Federal Soil Survey Laboratory Programme. 

Parsa [228] has described a sequential radiochemical method for the determination of thorium (and uranium) in soils. Mukhtar et al. [229] have described a laser fluorometric method for the determination of thorium (and uranium) in soils. Steam digestion has been employed in the preparation of soil samples for the determination of thorium (and uranium) [230]. Thorium (and uranium) were determined by X-ray fluorescence using a germanium planar detector and by chemometric techniques. No sample preparation was required in this method [231]. 

Nass et al. [238] used a delayed neutron counting technique to determine down to 50 ng of 235uranium in soils. Steam digestion has been employed in the preparation of soil samples for the determination of uranium (and thorium). 

Kawata et al. [ 128] have described the effects of headspace conditions on recoveries of volatile organic compounds from sediments and soils. Hewitt [129] compared three vapour partitioning headspace and three solvent extraction methods for the preparation of soil samples for volatile organic carbon determination in soils. Methanol extraction was the most efficient method of spiked volatile organic carbon recovery, which depended on the soil organic carbon content, the octanol-water partitioning coefficients of analytes and the extraction time. 

Preparation of Soil Samples On-site for GC/MS Analysis Preparation of Wipe and Non-soil Solid Samples On-site for GC/MS Analysis Preparation of Organic... 

SP 4 Recommended operating procedure for the preparation of soil samples... 

Soil samples have proved to be of critical importance in confirming the use of chemical warfare agents. Although the preparation of soil samples received little attention in the open literature during... 

Fig. 9.7. Sequence of steps to be taken for preparation of soil samples for y-spectrometry.

Preparation of Soil Sampling Protocols Sampling Techniques and Strategies... 

FIGURE 3.9 Preparation of soil samples for analysis by gamma speetrometry, ICP-OES, and alpha spectrometry. (Based on data from Regenspurg, S. et al., Geochim. Cosmochim. Acta, 74, 2082, 2010.)... 

Preparation of soil—sediment of water samples for herbicide analysis generally has consisted of solvent extraction of the sample, followed by cleanup of the extract through Uquid—Uquid or column chromatography, and finally, concentration through evaporation (285). This complex but necessary series of procedures is time-consuming and is responsible for the high cost of herbicide analyses. The advent of soUd-phase extraction techniques in which the sample is simultaneously cleaned up and concentrated has condensed these steps and thus gready simplified sample preparation (286). 

Analysis of soils is an important task in the environmental researches. Reliability of ICP-MS results of soil analysis mainly depends on chemical sampling. Recently microwave systems are widely used for preparation of different samples. Influence of microwave radiation on sample ensures a complete decomposition of sample, greatly increases the mineralization, and allows possible losses of volatile elements to be minimized. In the given study to intensify decomposition of soils we applied the microwave sample preparation system MULTIWAVE (Anton Paar, Austria and Perkin-Elmer, USA) equipped with rotor from 6 autoclaves with TEM reaction chambers of 50 ml volume. 

In practice, the number of soil samples that is actually analyzed is reduced by the preparation of composite samples. Here, multiple samples from a given replication and sampling period are blended together to yield one composite sample for analysis. Composite samples are statistically justifiable as they increase the precision with... 

A chloric acid digestion was used by Backer 2 391 for the preparation of tissue samples. The digest is simply diluted to determine iron, zinc, and copper. The tantalum sampling boat technique was used by Emmermann and Luecke 2531 to measure lead, zinc, and silver in prepared soil solutions. White 1S81 treated ashed plants with hydroxylamine in IN hydrochloric acid to reduce and dissolve oxides of manganese, prior to its determination by atomic absorption spectroscopy. 

Marsh et al. [47] have described an apparatus based on an autoanalyser system for the automatic preparation of soil extracts for mineral nitrogen determination. It consists of a reagent adder, which adds the correct volume of extractant for an approximately weighed amount of soil, and a sample preparation unit, which mixes, filters, dilutes and loads samples on to an autoanalyser sampler. A labour saving of 60% is achieved in this method compared to manual method. Examples are given of the determination of nitrate plus nitrate nitrogen and ammonium nitrogen. 

Soils and Sediments. This protocol (Figure 5) was developed for the preparation of soil and sediment samples for mutagenicity testing. It was designed to provide samples that accurately represent the mutagenic potential of the soil or sediment sample initially extracted and, if necessary, sufficiently fractionate the original material to isolate bioactive materials. Fractionation should be required only if the toxicity of the crude extract prevents determination of the mutagenic potential. 

The former UK Ministry of Agriculture and Food has also published [17] recommended soil preparation techniques for the determination of a wide range of metals and for the preparation of plant samples for analysis by dry combustion and the determination of ash. 

Recent work on soil sample preparation is reviewed below. Rubio and Une [20] have discussed the risks of soil sample contamination using inappropriate materials, containers and tools as well as possible analyte loss during sample loading. 

The effects of soil sample preparation procedures for the determination of chromium in soils have been reported [38]. The optimum conditions included the use of an homogeneous sample with a mass of less than 4 kg, a grain diameter of less than 0.25 mm, digestion with a solution of nitric acid plus perchloric acid (3 2) and hydrochloric acid after dry ashing, with the addition of 1% lanthanum or 1% ammonium chloride to eliminate interferences. 

Arce et al. [39] developed a flow injection analysis (F1A) system (Fig. 5.3) for online filtration of water samples prior to CE analysis. They also constructed a pump-driven unit for extraction and filtration of soil samples combined with CE in an online mode (automated sample transfer between pre-CE sample preparation step and the CE) [40]. The method was precise and four times faster than conventional methods of sample preparation with an off-line unit. Blood samples are centrifuged immediately to remove red blood cells and the serum is stored as discussed above. Sometimes, urine samples also contain precipitates which are removed by centrifuge. 

The ASTM procedure describes in detail the conditioning of wood samples, dissolution of preservatives, impregnation, preparation of soil, bottles, sterilization procedures, inoculation of wood samples with one or more strains of wood-destroying fungi, incubation of samples and duration of the test, and so on. The principal readout of the test procedure is a loss of weight of the wood sample after its exposure to microbial cultures. 

The unit formula for kaolinite has a Si/Al ratio of 1. This ratio is matched by its chemical composition, which suggests that soil kaolinites have little or no isomorphic substitution. Any differences from 1 could be due to surface coatings that were not removed during preparation of the sample. Most of the 10- to 100-mmol(+) kg-1 cation exchange capacity of kaolinite has been attributed to dissociation of OH groups at clay edges. However, if only one Si4+ of every 200 in the silica sheet were... 

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