The field of chemistry uses analysis in at least three ways: to identify the components of a particular chemical compound ( qualitative analysis ), to identify the proportions of components in a mixture ( quantitative analysis ), and to break down chemical processes and examine chemical reactions between elements of matter.

A matrix can have a considerable effect on the way a chemical analysis is conducted and the quality of its results.

This text clarified the concept of an element as a substance that could not be broken down by any known method of chemical analysis, and presented Lavoisier's theory of the formation of chemical compounds from elements.

Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of one or more of these components.

* List of chemical analysis methods

Conservators routinely use chemical and scientific analysis for the examination and treatment of cultural works.

* A. Walsh ( 1955 ), The application of atomic absorption spectra to chemical analysis, Spectrochim.

Atom probe has typically been employed in the chemical analysis of alloy systems at the atomic level.

Subsequently, atom probe has been used in the analysis of the chemical composition of a wide range of alloys.

They were used in 18th-century chemical studies for burning materials in closed glass vessels where the products of combustion could be trapped for analysis.

They can be analyzed using the tools of chemical analysis, e. g. spectroscopy and chromatography.

* Analytical chemistry is the analysis of material samples to gain an understanding of their chemical composition and structure.

The study was the first nationwide analysis measuring the presence of the chemical in U. S. water systems.

Here the analysis starts from the products, for example by splitting selected chemical bonds, to arrive at plausible initial reagents.

Pyrolysis gas chromatography mass spectrometry is a method of chemical analysis in which the sample is heated to decomposition to produce smaller molecules that are separated by gas chromatography and detected using mass spectrometry.

Mr. Clark found that orthodox procedures of deep plowing, use of chemical fertilizers and insecticides, plus the application of conservation principles of rotation and contouring, did not prevent sheet erosion in the potato fields and depreciation of the soil.

Subsequent Reports to Congress have documented chemical changes in soil and freshwater ecosystems, nitrogen saturation, decreases in amounts of nutrients in soil, episodic acidification, regional haze, and damage to historical monuments.

Many chaparral plant species require some fire cue ( heat, smoke, or charred wood, and chemical changes in the soil following fires ) for germination.

Such a use might be, for example: " 120 years of industry have dosed the area's soil with a noxious cocktail of heavy metals and chemical contaminants.

Because the porosity of the surface soil results in virtually zero runoff, lenses are easily polluted by fecal waste, burials, and chemical spills.

Others include mono-cropping, farming on steep slopes, pesticide and chemical fertilizer usage ( which kill organisms that bind soil together ), row-cropping, and the use of surface irrigation.

The loss of soil fertility due to erosion is further problematic because the response is often to apply chemical fertilizers, which leads to further water and soil pollution, rather than to allow the land to regenerate.

One of these is the Phoenix lander, which analyzed Martian polar soil for water and chemical and mineralogical constituents related to biological processes.

Geotechnical engineering uses principles of soil mechanics and rock mechanics to investigate subsurface conditions and materials ; determine the relevant physical / mechanical and chemical properties of these materials ; evaluate stability of natural slopes and man-made soil deposits ; assess risks posed by site conditions ; design earthworks and structure foundations ; and monitor site conditions, earthwork and foundation construction.

Environment-current issues: In the 2006 environment annual report, the Ministry of Environment reported that current major issues are global warming and preservation of the ozone layer, conservation of the atmospheric environment, water and soil, waste management and recycling, measures for chemical substances, conservation of the natural environment and the participation in the international cooperation.

: Radioactive or toxic chemical sites associated with its former defense industries and test ranges are found throughout the country and pose health risks for humans and animals ; industrial pollution is severe in some cities ; because the two main rivers which flowed into the Aral Sea have been diverted for irrigation, it is drying up and leaving behind a harmful layer of chemical pesticides and natural salts ; these substances are then picked up by the wind and blown into noxious dust storms ; pollution in the Caspian Sea ; soil pollution from overuse of agricultural chemicals and salination from poor infrastructure and wasteful irrigation practices

Treated pine that was traditionally treated using chromated copper arsenate or CCA, a toxic chemical mix for preserving timber that may leach chemicals into the soil which in turn can be drawn up into the plants, a concern for vegetable growers, where part or all of the plant is eaten.

Steiner responded with a lecture series on an ecological and sustainable approach to agriculture that increased soil fertility without the use of chemical fertilizers and pesticides.

shrinkage of the Aral Sea is resulting in growing concentrations of chemical pesticides and natural salts ; these substances are then blown from the increasingly exposed lake bed and contribute to desertification ; water pollution from industrial wastes and the heavy use of fertilizers and pesticides is the cause of many human health disorders ; increasing soil salination ; soil contamination from agricultural chemicals, including DDT

Soil is a natural body consisting of layers ( soil horizons ) that are primarily composed of minerals which differ from their parent materials in their texture, structure, consistency, colour, chemical, biological and other characteristics.

Mature soil profiles in temperate regions may include three master horizons A, B and C. The A and B horizons are called the solum or “ true soil ” as most of the chemical and biological activity that has formed soil takes place in those two profiles.

Humphry Davy, an English chemist was among the first to expound on the chemical basis of soil fertility and wrote in 1813: “ If land be unproductive, and a system of ameliorating it is to be attempted, the sure method of obtaining the object is to determine the cause of the sterility, which must necessarily depend upon some defect in the constitution of the soil, which may be easily discovered by chemical analysis .” His ideas were not immediately accepted.

Only a proper, artist-grade acrylic gesso should be used to prime canvas in preparation for painting with acrylic ( however acrylic paint can be applied to raw canvas if so desired without any negative effect or chemical reaction as would be the case with oils ).

Though the same chemical substance, ground-level ozone should not be confused with stratospheric ozone, or the ozone layer, which protects the earth from harmful ultraviolet rays.

Feynman also suggested that it should be possible, in principle, to make nanoscale machines that " arrange the atoms the way we want ", and do chemical synthesis by mechanical manipulation.

For instance, if one wishes to measure the pH of a seawater sample, the electrode should be calibrated in a solution resembling seawater in its chemical composition, as detailed below.

However, according to Naithani & Kakkar ( 2004 ), " all herbal preparations should be checked for toxic chemical residues to allay consumer fears of exposure to known neuro-toxicant pesticides and to aid in promoting global acceptance of these products ".

For a chemical reaction to proceed at a reasonable rate, there should exist an appreciable number of molecules with energy equal to or greater than the activation energy.

The initial members of the group had different assessments of which chemical precursors should be subject to export control.

The use of SSRI antidepressants with a 53-year-old man with multiple chemical sensitivities showed a dramatic improvement, which suggests, as with the general population, a subgroup of MCS patients may have an atypical depression and should be evaluated for this condition.

" Addictiveness " is a social category, argued Szasz, and the use of drugs should be apprehended as a social ritual rather than exclusively as the act of ingesting a chemical substance.

These chemical classes should be rotated so that selection pressure on the disease in limited as to avoid resistant strains of this disease.

Thus, some scientists take the view that the overall quantity, here called the " electrochemical potential ", should simply be called the " chemical potential ".

The more modern view is that " chemical potential " should mean the same thing as " electrochemical potential ", – but that in some contexts there is a separate concept – called here the " internal chemical potential " – that is the energy left when the " purely electrostatic component of electrochemical potential " is subtracted out.

The initial reaction should the spray be directed at the face, is the completely involuntary closing of the eyes ( sometimes described as leading to a disconcerting sensation of the eyelids " bubbling and boiling " as the chemical acts on the skin ), an instant sensation of the restriction of the airways and the general feeling of sudden and intense, searing pain about the face, nose, and throat.

Chemical activities should be used to define chemical potentials, where the chemical potential depends on the temperature T, pressure p and the activity a < sub > i </ sub > according to the formula:

In other words, the situation when all the pests except the most resistant ones are killed by a given chemical should be avoided.

Franklin knew from basic chemical principles the hydrophilic backbones should go on the outside of the molecule where they could interact with water.

Such fires should be extinguished with a wet chemical extinguisher.

The condition is a type of chemical burn rather than an allergic reaction and should be treated as such.

Hence, even if we agree to include in a definition polyphenolic structures with no tanning action, the term “ polyphenol ” should be restricted, in a strict chemical sense, to structures bearing at least two phenolic moieties independently of the number of hydroxyl groups they each bear.

Chemical shells were on stand-by during World War II, to be used in retaliation should the enemy employ chemical weapons first.

While the hazards of EtO are generally well known, it should be noted that all chemical sterilants are designed to kill a broad spectrum of organisms, by exposing them to high concentrations of reactive chemicals.

They argue that forced chemical castration is a " cruel and unusual punishment ", and therefore should be constitutionally prohibited by the Eighth Amendment.