What is the name of the lamp used in atomic absorption spectrophotometer?
hollow-cathode lamp
A hollow-cathode lamp (HCL) is type of cold cathode lamp used in physics and chemistry as a spectral line source (e.g. for atomic absorption spectrometers) and as a frequency tuner for light sources such as lasers.
What is atomic absorption spectrophotometer used for?
Atomic absorption spectrometry (AAS) is an easy, high-throughput, and inexpensive technology used primarily to analyze elements in solution. As such, AAS is used in food and beverage, water, clinical research, and pharmaceutical analysis.
What are the components of AAS?
The standard AAS instrument consists of four components: the sample introduction area, the light (radiation) source, the monochromator or polychromator, and the detector (figure 1).
What is the principle of atomic absorption spectrophotometer?
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.
What is hollow cathode lamp in AAS?
Hollow cathode lamps (HCL) are discharge lamps designed for use in Atomic Absorption (AA) instruments. They consist of a cathode made from the element of interest, an anode and an inert filler gas contained in a glass envelope.
How does a cathode lamp work?
This is a lamp in which the cathode is coated with the analyte metal of interest. Within the lamp, inert filler gas (neon or argon) is ionized by an electric current and these ions are then attracted by the cathode. The inert gas ions bombard the cathode and in so doing excite the metal ions coated on it.
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.
What causes atomic absorption?
The flame (thermal energy) causes the atom to undergo a transition from the ground state to the first excited state. When the atoms make their transition, they absorb some of the light from the beam. The more concentrated the solution, the more light energy is absorbed!
What is AAS in chemistry?
Atomic absorption spectrometry (AAS) detects elements in either liquid or solid samples through the application of characteristic wavelengths of electromagnetic radiation from a light source.
What type of result can AAS produce?
In clinical analysis, AAS can test for metals in whole blood, plasma, urine, saliva, brain and muscle tissue, the liver and hair. One example where atomic absorption spectroscopy can provide invaluable support is in measuring mercury levels in fish.
Why do we need atomic absorption spectroscopy?
Using an atomic absorption spectrometer, you can determine the concentration of many different elements in a sample. The spectrometer identifies the amount of metal in liquids and measures the quality of metal in a sample as well.
What is hollow cathode discharge?
The hollow cathode effect allows electrical conduction at a lower voltage or with more current in a cold-cathode gas-discharge lamp when the cathode is a conductive tube open at one end than a similar lamp with a flat cathode. In a hollow cathode, the electron emitting surface is in the inside of the tube.
How does an atomic absorption photometer measure light?
A: Like a spectrophotometer, an atomic absorption photometer measures how much light is absorbed when the light flux from a light source passes through a material to be measured.
How are atoms involved in the absorption of light?
The difference is that (1) atoms are involved here, rather than molecules, and (2) light is not absorbed prior to this atomic emission. Following atomization, a small percentage of the atoms absorb sufficient energy from the flame (as opposed to a light beam) so as to be promoted to an excited state.
What are the analytical methods of atomic absorption?
Flame Atomic Absorption Spectrometry Analytical Methods 3. Important Warning. WARNING. Eye, Explosion and Hearing Hazard Aspiration of perchloric acid and perchlorates into a nitrous oxide-acetylene flame can create an explosion hazard, which can result in death or serious personal injury including temporary or permanent impairment of hearing.
Which is the principle of atomic absorption and emission spectroscopy?
Principle of Atomic Absorption /Emission Spectroscopy 15.1 ATOMIC EMISSION-THE FLAME TEST When a small amount of a solution of a metal ion is placed in the flame of a Bunsen burner, the flame turns a color that is characteristic of the metal ion.
