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The atomic absorption spectrometer requires that the sample be atomized, broken down into individual atoms, before it is passed into the radiation beam for absorbance measurement. In flame AA, a liquid solution containing the sample is aspirated into a flame. This is achieved using a nebulizer, which mixes the sample solution with gaseous fuel and oxidant to form a uniformly mixed aerosol of the solution. There are several different phenomena which take place in the flame while the measurement is occurring. Each drop first dries to a small salt particle, then evaporates completely. The ion clusters heat further until they absorb enough energy to dissociate into free atoms in vapor state. The beam is passed through the flame and absorbance by the atomized species in the flame is measured. It should be noted that the absorbance is proportional to the concentration of ground state atoms in the flame.
The flame provides a complex and reactive atmosphere. Metal atoms can undergo chemical changes, forming, for example, refractory oxides or hydroxides. Atoms can also lose electrons to form ions. Any process which converts free ground state atoms to other forms lowers the sensitivity because the ground state atoms are the absorbing species.
Figure .24 shows a typical AA flame apparatus. The burner usually has a long narrow slot from which the flame emerges, and the light beam passes along the length of the slot. This allows for a longer absorbing path length, and better sensitivity. A commonly used flame is fueled with acetylene, with air for an oxidizer
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What is the simailarity and difference of flame emission and atomic absorption spectroscopy?
Both flame emission and atomic absorption spectroscopy are analytical techniques used to determine the concentration of elements in a sample. The main similarity is that they both rely on the excitation of atoms in the sample to emit or absorb specific wavelengths of light. The main difference is that in flame emission spectroscopy, the intensity of emitted light is measured, while in atomic absorption spectroscopy, the amount of light absorbed by the atoms is measured.
Can an AAA perform atomic emission spectroscopy?
Yes, an AAA (atomic absorption spectroscopy) can be used to perform atomic emission spectroscopy by measuring the energy emitted by atoms. This technique involves heating a sample to generate a plasma, which then emits characteristic light that is analyzed to identify and quantify elements.
What is flame atomization?
Flame atomization is a process in which a liquid sample is converted into a fine mist of droplets through the use of a flame. This mist is then heated to vaporize the liquid and produce atoms for analysis using techniques such as atomic absorption spectroscopy or atomic emission spectroscopy. This process allows for the detection and quantification of elements present in the liquid sample.
Why is source modulation used in atomic absorption spectroscopy?
Source modulation in atomic absorption spectroscopy is used to enhance sensitivity and reduce background noise. By modulating the lamp intensity at a specific frequency, it becomes easier to distinguish the absorption signal from the baseline noise, leading to better detection limits and accuracy in the analysis.
Working principle of atomic emission spectroscopy?
Atomic emission spectroscopy works by exciting atoms in a sample to higher energy levels using a flame or electrical discharge. When the atoms return to their ground state, they emit characteristic wavelengths of light. By analyzing the emitted light, the elemental composition of the sample can be determined.
What is the simailarity and difference of flame emission and atomic absorption spectroscopy?
Both flame emission and atomic absorption spectroscopy are analytical techniques used to determine the concentration of elements in a sample. The main similarity is that they both rely on the excitation of atoms in the sample to emit or absorb specific wavelengths of light. The main difference is that in flame emission spectroscopy, the intensity of emitted light is measured, while in atomic absorption spectroscopy, the amount of light absorbed by the atoms is measured.
When is flame emission spectroscopy used?
It can be used for element identification and can used in Atomic spectroscopy and can be used to help "atoms with low ionization potentials become ionized."
Can an AAA perform atomic emission spectroscopy?
Yes, an AAA (atomic absorption spectroscopy) can be used to perform atomic emission spectroscopy by measuring the energy emitted by atoms. This technique involves heating a sample to generate a plasma, which then emits characteristic light that is analyzed to identify and quantify elements.
What is flame atomization?
Flame atomization is a process in which a liquid sample is converted into a fine mist of droplets through the use of a flame. This mist is then heated to vaporize the liquid and produce atoms for analysis using techniques such as atomic absorption spectroscopy or atomic emission spectroscopy. This process allows for the detection and quantification of elements present in the liquid sample.
Why is source modulation used in atomic absorption spectroscopy?
Source modulation in atomic absorption spectroscopy is used to enhance sensitivity and reduce background noise. By modulating the lamp intensity at a specific frequency, it becomes easier to distinguish the absorption signal from the baseline noise, leading to better detection limits and accuracy in the analysis.
Why is atomic absorption not used for qualitative analysis?
For one thing, atomic absorption equipment is basically a fancier version of flame emission equipment (I'm unaware of any instrument capable of doing AA that can't also do FE), and flame emission doesn't require you to change tubes every time you want to check for another element.
Working principle of atomic emission spectroscopy?
Atomic emission spectroscopy works by exciting atoms in a sample to higher energy levels using a flame or electrical discharge. When the atoms return to their ground state, they emit characteristic wavelengths of light. By analyzing the emitted light, the elemental composition of the sample can be determined.
Determination of magnesium in tap water?
Magnesium in tap water can be determined through various analytical techniques such as atomic absorption spectroscopy, inductively coupled plasma optical emission spectroscopy, or colorimetric methods. These methods involve complexation reactions with specific reagents or instruments that can detect magnesium ions in the water sample. The specific method chosen will depend on the sensitivity required and the available equipment.
Why cant the concentration of iron be detected by flame emission photometry?
Flame photometry can be used for the measurement of elements which can easily be excited like Ca, K, Na, Ba, Cu etc. However due to low temperature of flame the elements like Fe can not be excited and hence not measured using Flame photometry.
What are the advantages and disadvantage of Flame emission?
Advantages of flame emission include high sensitivity, wide dynamic range, and speed of analysis. However, disadvantages can include interferences from other elements, the need for sample preparation, and potential contamination of the flame.
What are two ways to observe the emission spectra of a chemical?
The emission spectrum is the electromagnetic radiation spectrum of a particular chemical. The major ways this is observed is through special equipment designed for it, though flame emission spectroscopy is its own method, wherein burning a chemical produces a particular color of flame.
What is the difference between AAS and Flame photometer?
flame photometry is a type of atomic EMISSION spectroscopy. The sample is excited (raised to a high temperature), causing the emission of light. the wavelength of the emitted light is a function of the energy of the excited electrons, so each element has a characteristic set of wavelengths. usually a single wavelength is detected and the intensity of the emission is used to calculate concentration. Atomic adsorption works in the reverse way. A light of a standard wavelength (a wavelength characteristic of the target element) is passed through a flame containing the unknown substance, and the concentration of the target element is determined by the reduction in the energy of this light as it passes through the flame. the light is adsorbed by the electrons in the target element, kicking them into a higher orbit or completely out of the atom, depending on the energy involved. basically, one method involves the emission of the energy as an excited electron kicks back down to a lower state, and the other involves the adsorption of energy as an electron is kicked up an energy state. Same basic principle-change in electron energy relates to light of a specified wavelength and the change in the amount of that light can be measured and converted to a concentration.
