Soil sampling techniques

As the plastic liners are removed from the probe, they are capped on both ends, the appropriate labels affixed, and promptly placed in a freezer (an in-field sectioning technique used for further partitioning of the 0-15-cm core is described later in this section). By convention, red plastic caps are placed on top of the core (i.e., the end that was closest to the soil surface) and black caps are placed on the bottom. Use of the two-color capping system is important when the cores are sectioned at a later time. This approach is referred to as zero-contamination sampling and is the industry standard in field soil dissipation. 

Step 1. Soil probe with outer retainer sleeve (A), Inner probe (B), and probe liner (C) is inserted into soil profile. 

The inner probe (with liner) is removed, leaving the outer retainer sleeve in the soil profile. While the liner Is still in the inner probe, a red cap is carefully placed on the top of the liner. Next, the probe is inverted, the A liner removed from the inner probe, and the bottom of the liner 

Upper soil profile sample in liner with end caps 

Outer retainer sleeve (A) remains in soil to prevent drag down of surface residues to lower soil profile 

---

Meriweather et al. [277] has suggested a new type of pedologically-based soil sampling technique based on the soil horizon rather than incrementally with depth for the assessment of radionuclides in soil. He gives an example where classical sampling approaches would lead to erroneous conclusions about anthropogenic contamination. 

Soil sampling technique Soil Soil sol. Soil Soil sol. Soil Soil sol. Soil Soil sol. Soil Soil sol. Ref. 

Soil sampling techniques, for instance, were instrumental In the discovery of the large Navan (Tara) zinc-lead deposit in Ireland in 1969. 

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. 

Quinn, K., S. Wittmann and R. Lee. Use of Soil Gas Sampling Techniques for Assessment of Groundwater Contamination. In Management of Uncontrolled Hazardous Waste Site Proceedings, Hazardous Materials Control Research Institute, Washington, D.C., 1985. 

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... 

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

B. Localized Sampling Techniques in Solution and Soil Culture Systems... 

A commonly used extraction technique involves shaking soil with a suitable solvent on a mechanical shaker at about 300 rpm. After extraction, the soil extracts are collected by centrifugation followed by decantation or filtration. This technique could be used for any amount of soil samples (from 10 to >100g). Soil samples greater than 100 g require efficient agitation to achieve acceptable recoveries. 

This is a relatively new technique that is used for PCBs and other nonpolar, volatile and semi-volatile organic compounds. Typically, a small aliquot of soil sample (0.5-20 g) is used for the extraction. Soil samples are extracted with one or more organic solvents using microwave energy at elevated temperature (100-115 °C) and pressure (50-175 psi). This method uses less solvent and takes significantly less time than Soxhlet extraction but is limited to thermally stable compounds. 

Trace analysis of soil samples often requires post-extraction cleanup to remove coextracted matrix interferences. There are several difficulties that may arise during chromatographic analysis due to interferences present in sample extracts. To avoid these and other issues, one or more of the following cleanup techniques are often used. 

ASTM. 1998e. ASTM E 1727. Standard practice for field collection of soil samples for lead determination by atomic spectrometry techniques. American Society for Testing and Materials. 

Mid-IR spectroscopy, alongside gravimetric and molecular weight determinations, has also been used to analyse the biodegradation by a thermophilic bacterium (isolated from soil) of an LDPE film [44], The mid-IR studies were undertaken using the ATR sampling technique on control samples, samples that had been UV irradiated, and samples that had been UV irradiated then incubated with bacteria. The study showed that the particular bacterial strain was capable of utilising standard and photo-oxidised polyethylene as the sole carbon source. 

Berset JD, Ejem M, Holzer R, Lischer P (1999) Comparison of different drying, extraction and detection techniques for the determination of priority polycyclic aromatic hydrocarbons in background contaminated soil samples. Anal Chim Acta 383(3) 263-275... 

Two commercial partial extraction techniques improve anomaly contrast in B horizon soil samples compared to aqua regia-ICPMS for Cu and Au. However, whereas the MMIsm and Bio LeachSM Cu profiles are similar, the MMIsm Au signal is much larger than that for Bio LeachSM. Analysis of samples at different depths down the B soil horizon profile indicates that the geochemical response from these methods is depth dependant. 

---