Chemical sample, solid

Chemical kit, 8, 9 Chemical sample, liquid, 6.1 Chemical sample, solid, 6.1 Chemical sample, toxic, liquid or solid, 6.1 First aid kit, 9 Gas identification set, 2.3 Gas sample, non-pressurised, n.o.s., not refrigerated liquid, 2.1, 2.3 Permeation devices, containing dangerous goods, for calibrating air quality monitoring Samples, explosive other than initiating explosives, 1... 

Insufficient testing is one of the major causes of method failure. The amount of data needed to publish a new procedure in a peer-reviewed journal and the procedural detail supplied therein are often insufficient to allow a different user to validate a method rapidly. The developer should evaluate if the method will work using chemicals, reagents, solid-phase extraction columns, analytical columns, and equipment from various vendors. Separate lots of specific supplies within a vendor should be evaluated to determine if lot-to-lot variation significantly impacts method performance. Sufficient numbers of samples should be assayed to estimate the lifetime of the analytical column and to determine the effects of long-term use on the equipment. 

Preliminary studies into a third variable, the partial pressure of water vapor in the system, are discussed in Part 3 of the Results and Calculations section. Each calorimetric sample ( 1 g, 13.47 mass % bitumen) came from a large sample of "reconstructed" oil sand consisting of Athabasca bitumen loaded onto a chemically inert solid support material (60/80 mesh acid washed Chromosorb W) of well-defined particle size. 

NIR spectroscopy is probably the most successful technique for the development of qualitative and quantitative methods in the pharmaceutical industry. NIR spectra contain both chemical and physical information from samples (solid and liquid). Spectra can be acquired off-line in three different modes transmittance, reflectance and transflectance. In all cases, the spectra are obtained in a few seconds without or minimum sample pretreatment. Multivariate data analysis techniques are usually needed for the development of the... 

Freeze-Dried Samples. Solid Materials and Tissues. These are first cut into approximately 1-inch cubes, frozen on a Teflon cookie sheet in a freezer, and placed in 1200-ml. freeze-dry flasks to capacity. The flasks are attached to the freeze-dried (lyophilizer) manifold, the valves are opened to vacuum, and the flasks are evacuated. The water from the tissues is trapped on a condenser. The dry tissues (drying time about 2-3 days) are removed from the lyophilizer and compressed into thin-walled aluminum cans with a Carver Laboratory press fitted with a special die, at about 24,000 lb. pressure (total). From 150-250 grams of the dry material, representing 500-1000 grams of fresh tissue, can be packed into a single can. The cans are sealed with a hand sealer and set aside for counting. Samples can be removed from the cans at a later date for chemical analysis or beta-emitter analyses. 

The resolution of the atomic force microscope depends on the radius of curvature of the tip and its chemical condition. Solid crystal surfaces can often be imaged with atomic resolution. At this point, however, we need to specify what Atomic resolution is. Periodicities of atomic spacing are, in fact, reproduced. To resolve atomic defects is much more difficult and usually it is not achieved with the atomic force microscope. When it comes to steps and defects the scanning tunneling microscope has a higher resolution. On soft, deformable samples, e.g. on many biological materials, the resolution is reduced due to mechanical deformation. Practically, a real resolution of a few nm is achieved. 

Air sampling for occupational exposure to pesticides normally consists of measurement of pesticide concentrations in the worker s breathing zone, with a portable air-sampling pump and a sampling train which includes some type of collection device. The latter device, or sampling media, selected are based on the physical and chemical properties of the compound to be measured. Field workers may be exposed to chemical vapors, solid particulates or water-based aerosols. Examples of sampling media include membrane filters, sorbent tubes, polyurethane foam and charcoal. A discussion of pesticide exposure provides a useful review of methods for respiratory exposure measurement (Nigg etal, 1990). 

In contrast, when sampling bulk material, the material cannot generally be viewed as a set of distinct units. For example, we sample liquids from tanks, drums, and pipelines, and particulate solids such as ore, powders, and soil. Individual units cannot be identified for sampling. Rather, we must decide on a sample mass Mg or volume the chemical sample size. Further, we must be concerned about whether to composite samples, and, if so, how much to include in each increment of the composite. An additionaJ complication is the restriction on the sample mass that must be used in a chemical analysis due to the method or instrumentation. In fact, a subsample is usually taken in the lab. 

Representative samples were taken during the bottling procedure to determine a number of trace elements (As, Cd, Cu, Hg, Mn, Pb, Sn, Tl, Zn) in Antarctic coastal marine sediment by Solid Sampling Zeeman Electrothermal Atomization Atomic Absorption Spectrometry (SSZ-ETA-AAS) (see Table 11.3). This technique is particularly suited to homogeneity control because of the usually low sample mass (0.1-10 mg) and the high number of parallel measurements (10-100). Additionally, all measurements are performed without any chemical sample... 

Fig. 15. Chemical composition of brine samples (solid dots from (a) Belle Isle mine (b) new Weeks Island mine (Markel Mine) (c) upper level Weeks Island mine and (d) lower level Weeks Island mine. All data normalized to 19,000 mg/1 chloride. Bars and open circles denote average seawater and formation waters of Louisiana, respectively. 

Composition of pore water is a highly sensitive indicator for reactions between chemicals on solid substrates and the aqueous phase which contacts them while the direct recovery and analysis of water-borne constituents can be seen as a major advantage of this approach, there are several difficulties, particularly arising from the sampling and sample preparation. 

Types of samples include rain, surface water, ground water, drinking water, seawater, and wastewater. The various types have different chemical constituents, solids content, and pH that may require distinctive collection and analysis techniques. Information should be obtained on the expected radionuclide content of the water to guide initial processing, sample preservation, and any requirement for rapid shipping and prompt analysis. 

Specific treatment combinations can be designed to match airborne contaminants from the physical or chemical operations, the type of sample (solid, liquid, gas), and the quantity that is processed. For example, sample preparation rooms where soil and vegetation are dried, ashed, ground and sieved require particle filter combinations but not charcoal beds and scrubbers. For treating laboratory air, the multiple stage filter system should be based on the expected maximum radionuclide concentration and airborne fraction of the processed samples. Typical combinations include pre-filters, HEPA filters and charcoal beds. 

Related Terms Aerosols, see Aerosols, p.3 Ammunition, see Ammunition, p.8 Burster, see Ammunition, p.8 Cartridges, see Ammunition, p.8 Chemical sample, toxic, liquid or solid, see Chemical Kits and Samples, p.40 Expelling charge, see Ammunition, p.8 Flammable, see Flammable Solids and Division 4.1, p.99... 

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