How mercury is Analysed?
Analytical techniques for measuring mercury include cold vapor atomic absorption spectroscopy, cold vapor atomic fluorescence spectroscopy, and direct analysis by thermal decomposition.
What is hydride generation technique?
Hydride generation (HG) is a very effective analytical technique developed to separate hydride forming metals, such as Se and As, from a range of matrices and varying acid concentrations. This technique is also effective at separating mercury from a range of matrices.
What is cold Vapour AAS?
Definition: A type of atomic absorption spectrometry where no vaporisation step is required because the sample is a volatile heavy metal such as mercury, which is a vapour at room temperature.
What is the principle of atomic absorption spectroscopy?
AAS is an analytical technique used to determine how much of certain elements are in a sample. It uses the principle that atoms (and ions) can absorb light at a specific, unique wavelength. When this specific wavelength of light is provided, the energy (light) is absorbed by the atom.
How do you test a sample for mercury?
To test for the various forms of mercury, more than one type of sample may be collected and tested.
- Blood is primarily tested to detect the presence of methyl mercury.
- Urine is used to test for metallic mercury and inorganic forms of mercury, but it cannot be used to determine exposure to methyl mercury.
What is graphite furnace atomic absorption spectrometry?
Graphite furnace atomic absorption spectroscopy (GFAAS) (also known as Electrothermal Atomic absorption spectroscopy (ETAAS)) is a type of spectrometry that uses a graphite-coated furnace to vaporize the sample. The atoms absorb ultraviolet or visible light and make transitions to higher electronic energy levels.
What is a hydride and how is it generated?
They are all very reactive and readily react with various compounds. For example, when an alkali metal reacts with hydrogen gas under heat, an ionic hydride is produced. Alkali metal hydrides also react with water to produce hydrogen gas and a hydroxide salt: MH(s)+H2O(l)⟶MOH(aq)+H2(g)
What is flame atomic absorption?
Flame atomic absorption is a very common technique for detecting metals and metalloids in environmental samples. The flame serves as a “sample holder”, as the light passes through the atoms and flame simultaneously, and the absorbance of light calculated.
Can mercury be atomized?
Because of the relatively poor sensitivity for mercury provided by traditional flame atomic absorption, alternative atomization techniques for the AA determination of mercury have been developed. The cold vapor atomic absorption technique for mercury has received the greatest attention.
Which gas is used in AAS?
Typical gases used in AAS are Nitrogen and Argon.
Which detector is used in atomic absorption spectroscopy?
A photodiode is a photoelectric transducer that produces an electric signal, or current, I, which results from absorption of photons.