LSM Analytical Services has evaluation methods for trace Evaluation of metals and oxides by atomic absorption spectroscopy. It is a technique used to determine the concentration of a particular metal in a sample. It usually includes using a fire to atomise the sample, but other methods such as a graphite furnace can also be utilized. There are 3 steps involved in Putting a liquid sample into an atomic gas
- Evaporation of the liquid to make a sterile sample
- Vaporising the sound sample into a gas
- Atomisation to break down the chemicals present into free atoms
Flame atomic absorption spectrometry Is a fast and effortless technique with an extremely large sensitivity, but expert knowledge is required in its use as issues arise from chemical and spectral interferences. Atomic absorption spectrometers utilize the absorption of Light to gauge the concentration of gas phase atoms. The light that is focused to the fire is produced by a hollow cathode lamp, inside which is the sample and an anode. A high voltage is passed between the cathode and anode and the metal atoms are excited into creating light with a particular emission spectrum. An atom is made up of core containing neutrons and protons. It Also includes a surrounding number of electrons, which can be bound to the heart at different energy levels. When an electron makes a transition from a specific energy level of an atom to a lower energy level, a photon of energy is released, which is equal in energy to the reduced level for the electron. The photon creates an atomic spectral line.
The frequency v where the spectral line happens is related to the energy E by Planck’s law; E = hd, where h is Planck’s constant. The atomic absorption spectroscopy generated could be characterised by both emission and an absorption coefficients. As the amount of energy put to the fire is known and the amount emitted can be detected, it is possible to compute the concentration of the element present. Special Chemical and optical properties of the components being analysed are important. As an example, concern could concentrate on traces of radioactive metallic atoms, or tendency to form compounds and anions negatively charged atoms. Both of these factors can provide misleading results. Flame properties are also very significant. These attributes include flame temperature, flame-line angle relative to the sensor, gas flow rate and constant atomizer function.