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#Hollow cathode lamp block diagram free

Depending on it, AAS is of two types Flame-AAS, and electrothermal or graphite furnace-AAS The atomizers most commonly used nowadays are flames and electrothermal (graphite tube) atomizers.

Atomizers: In order to analyze a sample for its atomic constituents, the element has to be atomized.

The block diagram illustrating the instrumentation of atomic absorption spectroscopy can be shown as: Atomic absorption spectroscopy instrumentation The absorbance is given by Beer-Lambert’s law the logarithmic ratio of the intensity of incident light to the intensity of absorbing species. When a metal atom is changed into gas and light is passed from the sources, the ground state of the atom gets excited by absorbing the radiation of a particular wavelength. The process by which gaseous metal atoms are produced into the flame can be illustrated as: If the light of resonance wavelength is passed through the flame containing the atoms which are analyte, the part of the light will be absorbed and the extent of absorption will be directly proportional to the number of ground state atoms present in the flame. A large number of the gaseous metal atom remains in the ground state, and are capable of absorbing radiant energy of their specific wavelength. If a solution containing metal salt (M +X –) is aspirated to the flame, a vapor that contains atoms of metal may be formed. Principle of atomic absorption spectroscopy The modern form of AAS was developed by Australian Chemist, Sir Alan Walsh in the 1950s.

#Hollow cathode lamp block diagram free

Because the atomic absorption method is largely free of interference and the set of electronic energy levels is specific to that element, it is a highly good analytical technique with great sensitivity. It is used to determine the concentration of metals present in a sample to be analyzed.ĪAS can be used to quantify more than 70 different elements either in solution or solid form and possesses wider applications in clinical analysis, food analysis, the pharmaceutical industry, the mining sector, and so on. Difference between flame photometry and atomic absorption spectroscopyĪtomic absorption spectroscopy (AAS) is an absorption spectroscopic method that uses the absorption of light by free atoms in a gaseous state to determine the quantitative composition of chemical components.Disadvantages of atomic absorption spectroscopy.Advantages of atomic absorption spectroscopy.

Application of atomic absorption spectroscopy.Interferences in atomic absorption spectroscopy.Atomic absorption spectroscopy instrumentation.Principle of atomic absorption spectroscopy.(l)Solute-volatilization interference occurs when the rate of volatilization of aerosol particles changes due to the lack or presence of a concomitant. (k)The interfering substance provided in excess to avoid spectral interferences is known as a radiation buffer. (j)Chemical interference is defined as a change in absorption properties or an analyte's emission caused by chemical processes such as atomization. (i)The phenomenon of spectral interference is the overlapping of an analyte's absorption line by another interfering species. (h)The absorbing back of emitted radiation by non-excited atoms in the lamp is referred to as self-absorption. (g)Sputtering is the process of forming atomic clouds in a hollow cathode lamp. (f)A hollow cathode tube is a type of glass tube that is frequently used in atomic absorption studies. (e)Pressure broadening is the process by which the collision of absorbing or emitting species with other ions generates a broadening of spectral lines compared to normal ones.

(d)Atomization is the process of converting samples to atoms. (c) The ionization suppressor allows for greater electron concentration to be introduced, which improves sensitivity. (b) In Atomic absorption spectroscopy, protective agents are chemicals that generate stable volatile species and overcome interference. (a)Cations that interact with the analyte and remove chemical interferences are referred to as releasing agents.