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Elemental analysis
 
 
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Elemental analysis is a process where a sample of some material (e.g., soil, waste or drinking water, bodily fluids, minerals, chemical compound
Chemical compound

A chemical compound is a Chemical substance consisting of two or more different chemical element Chemical bond together in a fixed mass ratio that can be split into simpler substances....
s) is analyzed for its elemental
Chemical element

A chemical element is a type of atom that is distinguished by its atomic number; that is, by the number of protons in its atomic nucleus. The term is also used to refer to a pure chemical Chemical substance composed of atoms with the same number of protons....
 and sometimes isotopic
Isotope

Isotopes are any of the different types of atoms of the same chemical element, each having a different atomic mass . Isotopes of an element have atomic nucleus with the same number of protons but different numbers of neutron....
 composition. Elemental analysis can be qualitative (determining what elements are present), and it can be quantitative (determining how much of each are present). Elemental analysis falls within the ambit of analytical chemistry
Analytical chemistry

Analytical chemistry is the study of the chemical composition of natural and artificial materials. Unlike other major sub disciplines of chemistry such as inorganic chemistry and organic chemistry, analytical chemistry is not restricted to any particular type of chemical compound or chemical reaction....
, the set of instruments involved in deciphering the chemical nature of our world.

For synthetic george chemists, elemental analysis or "EA" almost always refers to CHNX analysis — the determination of the percentage weights of carbon, hydrogen, nitrogen, and heteroatoms (X) (halogens, sulfur) of a sample.






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Elemental analysis is a process where a sample of some material (e.g., soil, waste or drinking water, bodily fluids, minerals, chemical compound
Chemical compound

A chemical compound is a Chemical substance consisting of two or more different chemical element Chemical bond together in a fixed mass ratio that can be split into simpler substances....
s) is analyzed for its elemental
Chemical element

A chemical element is a type of atom that is distinguished by its atomic number; that is, by the number of protons in its atomic nucleus. The term is also used to refer to a pure chemical Chemical substance composed of atoms with the same number of protons....
 and sometimes isotopic
Isotope

Isotopes are any of the different types of atoms of the same chemical element, each having a different atomic mass . Isotopes of an element have atomic nucleus with the same number of protons but different numbers of neutron....
 composition. Elemental analysis can be qualitative (determining what elements are present), and it can be quantitative (determining how much of each are present). Elemental analysis falls within the ambit of analytical chemistry
Analytical chemistry

Analytical chemistry is the study of the chemical composition of natural and artificial materials. Unlike other major sub disciplines of chemistry such as inorganic chemistry and organic chemistry, analytical chemistry is not restricted to any particular type of chemical compound or chemical reaction....
, the set of instruments involved in deciphering the chemical nature of our world.

For synthetic george chemists, elemental analysis or "EA" almost always refers to CHNX analysis — the determination of the percentage weights of carbon, hydrogen, nitrogen, and heteroatoms (X) (halogens, sulfur) of a sample. This information is important to help determine the structure of an unknown compound, as well as to help ascertain the structure and purity of a synthesized compound.

Methods

The most common form of elemental analysis, CHN analysis, is accomplished by combustion analysis
Combustion analysis

Combustion analysis is a method used in both organic chemistry and analytical chemistry to determine the chemical elemental composition of a pure organic compound by combusting the sample under conditions where the resulting combustion products can be quantitatively analyzed....
. In this technique, a sample is burned in an excess of oxygen, and various traps collect the combustion products — carbon dioxide, water, and nitric oxide. The weights of these combustion products can be used to calculate the composition of the unknown sample.

Other quantitative methods include:
  • Gravimetry
    Gravimetry

    Gravimetry is the measurement of a gravity field. Gravimetry may be used when either the magnitude of gravitational field or the properties of matter responsible for its creation are of interest....
    , where the sample is dissolved and then the element of interest is precipitated and its mass measured or the element of interest is volatilized and the mass loss is measured.
  • Optical atomic spectroscopy
    Atomic spectroscopy

    Atomic spectroscopy is the determination of elemental composition by its electromagnetic or mass spectrum. Atomic spectroscopy is closely related to other forms of spectroscopy....
    , such as flame atomic absorption, graphite furnace atomic absorption, and inductively coupled plasma atomic emission, which probe the outer electronic structure of atoms.


To qualitatively determine which elements exist in a sample, the methods are:
  • Mass spectrometric atomic spectroscopy
    Atomic spectroscopy

    Atomic spectroscopy is the determination of elemental composition by its electromagnetic or mass spectrum. Atomic spectroscopy is closely related to other forms of spectroscopy....
    , such as inductively coupled mass spectrometry, which probes the mass of atoms.
  • Other spectroscopy which probes the inner electronic structure of atoms such as X-ray fluorescence
    X-ray fluorescence

    X-ray fluorescence is the emission of characteristic "secondary" X-rays from a material that has been excited by bombarding with high-energy X-rays or gamma rays....
    , Particle-Induced X-ray Emission, x-ray photoelectron spectroscopy
    X-ray photoelectron spectroscopy

    X-ray photoelectron spectroscopy is a quantitative spectroscopic technique that measures the elemental composition, empirical formula, chemical state and electronic state of the elements that exist within a material....
    , and Auger electron spectroscopy
    Auger electron spectroscopy

    Auger electron spectroscopy is a common analytical technique used specifically in the study of surface science and, more generally, in the area of materials science....
    .
  • Chemical methods
    • sodium fusion
    • Schöniger oxidation
      Schöniger oxidation

      In chemistry, the Sch?niger oxidation is moethod of elemental analysis developed by Kurt Sch?niger.The test is conducted in an Erlenmeyer flask, or in a separatory funnel....