Sampling soil

To detect surface anomalies caused by hydrocarbon accumulations often very small amounts of petroleum compounds have leaked into the overlying strata and to the surface. On land, these compounds, mostly gases, may be detectable in soil samples. 

CT was applied to various types of samples, such as a) concrete, b) asphalt c) wood and trees d) soil samples e) ceramic materials f) works of art. 

Particulate gravimetry is commonly encountered in the environmental analysis of water, air, and soil samples. The analysis for suspended solids in water samples, for example, is accomplished by filtering an appropriate volume of a well-mixed sample through a glass fiber filter and drying the filter to constant weight at 103-105 °C. 

Using this value for k and the signal obtained for the extracted and diluted soil sample gives a fluoranthene concentration of... 

Dispersion staining is useful for rapid deterrnination of refractive index and dispersion. It is appHed most often, however, for needle-in-a-haystack detection of any particular substance in a mixture such as chrysotile in insulation, cocaine in dust samples, quartz in mine samples, or any particular mineral, eg, tourmaline, in a forensic soil sample. 

To obtain reproducible antibiotic production by fermentation, it is necessary to obtain a pure culture of the producing organism. Pure cultures are isolated from mixed soil sample populations by various streaking and isolation techniques on nutrient media. Once a pure culture has been found that produces a new antibiotic typically on a mg/L scale, improvement in antibiotic yield is accompHshed by modification of the fermentation medium or strain selection and mutation of the producing organism. Production of g/L quantities may take years to accomplish. 

The development of methods of analysis of tria2ines and thek hydroxy metabohtes in humic soil samples with combined chromatographic and ms techniques has been described (78). A two-way approach was used for separating interfering humic substances and for performing stmctural elucidation of the herbicide traces. Humic samples were extracted by supercritical fluid extraction and analy2ed by both hplc/particle beam ms and a new ms/ms method. The new ms /ms unit was of the tandem sector field-time-of-flight/ms type. 

A multiresidue analytical method based on sohd-phase extraction enrichment combined with ce has been reported to isolate, recover, and quantitate three sulfonylurea herbicides (chlorsulfuron, chlorimuron, and metasulfuron) from soil samples (105). Optimi2ation for ce separation was achieved using an overlapping resolution map scheme. The recovery of each herbicide was >80% and the limit of detection was 10 ppb (see Soil chemistry of pesticides). 

In 1976 scientists at the Merck Corporation discovered a complex of eight closely related natural products, subsequently named avermectins A through in a culture of Streptomjces avermitilis MA-4680 (NRRL8165) originating from a soil sample collected at Kawana, Ito City, Shizuoka Prefecture, Japan and isolated by the Kitasato Institute. Their stmctures are shown in Figure 1 (1 6). They are among the most potent anthelmintic, insecticidal, and acaricidal compounds known. 

The results of analysis of samples from Desnyansky and Dniper water-supply stations water are given in the report concerning the contents of PCDD and soil samples concerning the contents of triazoles. 

The influence of soil ageing on the recovery of POPs from spiked soil samples was also assessed. Spiked lettuce samples were subjected to in vitro gastrointestinal extraction to assess the bioavailability of Endosulfan compounds. All samples (soil and lettuce) were extracted using pressurised fluid extraction and analysed using gas chromatography with mass selective detection. 

COMPARISON OF MICROWAVE ASSISTED EXTRACTION METHODS FOR THE DETERMINATION OF PLATINUM GROUP ELEMENTS IN SOIL SAMPLES BY ELECTROTHERMAL ATOMIC ABSORPTION SPECTROMETRY AFTER PHASE SEPARATION-EXTRACTION... 

Elemental analysis of organie and inorganie samples requires partial or total dissolution of the sample prior to speetrometrie analysis. Mierowave-assisted extraetion (MAE) provides an alternative to traditional digestion methods and it is reeognized as one of the most effieient methods for the dissolution of soil samples. 

There is a direct and an indirect method of measuring specific soil resistivity. The direct method is carried out in the laboratoiy on a soil sample using a soil box as shown in Fig. 3-16. The resistivity of a soil specimen of cross-section, S, and length, I, is measured and the specific resistivity determined ... 

When making measurements in the soil box, it has to be remembered that soil samples can change from their original condition and this will have an effect on the resistivity. Soil resistivity measurements in the soil box only give accurate results with cohesive soils. However, the order of magnitude of the specific resis-... 

Checking for land contamination, e.g. analysis of soil samples. Record keeping. 

Detection limits of 0.0001 to 0.01 mg/P in soil samples and 0.1 to 1.0 mg/ in water samples have been reported. Lappala (1984) reported the results of repeated sampling on successive days at a... 

Soil samples have been found to contain 500 ppm of TCE and 750 ppm of benzene. Two technologies are being considered to remediate the soil. One is based on vapor extraction combined with carbon adsorption. The other technique is simply to inject steam into the ground, vaporize the solvents and then withdraw them as a vapor extraction technique, discharging the... 

This method can also be used to analyse soil samples. For instance, fenpropi-morph, which is a non-polar pesticide with good UV sensitivity but poor selectivity, has, after treatment, been determined in soil samples (31). In this example, an amount of soil was extracted overnight with acetonitrile this was then poured into a Buchner filter and rinsed with the same solvent. The acetonitrile solution was concentrated and, prior to LC analysis, the extract was diluted with water and 100 p.1 were then injected into the LC system. 

The experimental conditions are shown in Table 13.1, while Figure 13.9 shows the chromatogram of a soil sample extract spiked with fenpropimorph obtained by this method, plus the chromatogram from the two columns connected in series without column switching. 

Figure 13.9 Coupled-column RPLC-UV (215 nm) analysis of 100 p.1 of an extract of a spiked soil sample (fenpropimoiph, 0.052 mg Kg ). LC conditions C-1, 5 p.m Hypersil SAS (60 m X 4.6 mm i.d.) C-2, 5 p.m Hypersil ODS (150 m X 4.6 mm i.d.) M-1, acetonitrile-0.5 % ammonia in water (50 50, v/v) M-2, acetonitrile-0.5 % ammonia in water (90 10, v/v) flow-rate, 1 ml min clean-up volume, 5.9 ml transfer volume, 0.45 ml. The dashed line represents the cliromatogram obtained when using the two columns connected in series without column switcliing. Reprinted from Journal of Chromatography A, 703, E. A. Hogendoom and R van Zoonen, Coupled-column reversed-phase liquid cliromatography in envir onmental analysis , pp. 149-166, copyright 1995, with permission from Elsevier Science.

J. V. Sancho, C. Hidalgo, E. Hernandez, E. J. Eopez, E. A. Hogendoorn and E. Dijkman, Rapid determination of glyphosate residues and its main metabolite aminomethylpho-sphonic acid (AMPA) , in soil samples by liquid cliromatogr aphy, Int. J. Environ. Anal. Chem. 62 53-63 (1996). 

Erd-probe, /. soil sample soil test, -rauch,... 

Test pits permit visual examination of the soil in place. Such pits also allow manual sampling of undisturbed soil samples. These samples can be taken from the side walls of the pit. 

Mechanical analyses determine the particle-size distribution in a soil sample. The distribution of coarse particles is determined by sieving, and particles finer than a 200 or 270-mesh sieve and found by sedimentation. 

Soil samples from the levels in which structure or pipes are to be laid are filled to the top of screw capped bottles, and bacteriological tests ire made within 24 hours. 

Many industrial processes give rise to pollutants which can present a health problem. Quantitative analysis of air, water, and in some cases soil samples, must be carried out to determine the level of pollution, and also to establish safe limits for pollutants. 

Geological surveys require the services of analytical chemists to determine the composition of the numerous rock and soil samples collected in the field. A particular instance of such an exercise is the qualitative and quantitative examination of the samples of moon rock brought back to Earth in 1969 by the first American astronauts to land on the moon. 

No satisfactory direct gravimetric procedure is available but nitrite can be oxidised to nitrate by permanganate or cerium(IV) and then determined in that form. The determination of total nitrate + nitrite is an important analysis, e.g. for soil samples. Nitrite may be destroyed using urea, sulphamic acid or hydrazine sulphate the reaction with the former is ... 

If the designer is to do the job properly, it is important to have accurate data on which to base calculations. That is why test borings and proper laboratory analysis to determine the E value of the soil sample are essential. An arbitrary textbook selection of a soil modulus should always be avoided. However, if a pipe is to be buried deeper than the sampling zone that underwent laboratory testing to determine E and if the test bore shows the deeper material to be equal or better, then the designer may increase the E value proportionally to the square root of the differential soil stress. 

A secondary metabolite produced by Tolypocladium inflation. This fungus was initially isolated in a soil sample collected in Norway. Cyclosporin A is a cyclic undecapeptide. Inside cells, cyclosporine A binds its immunophillin receptor known as cyclophillin. Like the FK506-FKBP12 complex, cyclosporin A-cyclophillin binds and inhibits the protein phosphatase calcineurin. 

Rapamycin is a macrocyclic lactone produced by Streptomyces hygroscopious. This bacterium was originally cultured from a soil sample collected on Easter Island (known locally as Rapa Nui hence the name rapamycin). Parenthetically, rapamycin shares an interesting mode of action with two other antifungal and immunosuppressive compounds, FK506and cyclosporin A. Inside cells, rapamycin first binds to FKBP12, a small protein receptor known as an immunophilin. FKBP12 is not an essential protein but is an important cofactor required for rapamycin to bind and inhibit TOR. 

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