1. Definition
Atomic Absorption Spectrophotometer (AAS) is a tool used in analytical methods for the determination of metallic elements and metalloids based on the absorption of radiation absorption by free atoms.
2. Basic Principles
Atomic absorption spectrophotometer (AAS) is a technique kuantitafif analysis of the elements of usage is very wide in many areas because the procedure is selective, specific, cost analysis is relatively inexpensive, high sensitivity (ppm-ppb), can easily create a matrix in accordance with the standards, analysis time is very quick and easy to do. AAS is generally used for elemental analysis, atomic absorption spectrophotometer single beam systems are also known and the double beam UV-VIS spectrophotometer withdrawal. Formerly known flame photometer that can only analyze the elements that can emit particularly groups IA and IIA elements. Generally light used is concave cathode lamps which its use only for the analysis of one element only.
AAS method the principle of absorption of light by atoms. The atoms absorb the light at a particular wavelength, depending on the nature of the element. Atomic absorption method just depends on the comparison and does not depend on temperature. Each tool AAS consists of three components, namely atomized units, sources of radiation, fotometerik measuring system.
AAS technique into a sophisticated tool in the analysis. This is because prior to the measurement does not necessarily require a separation of the elements is determined by the possibility of determining the presence of an element with another element can be done, provided the hollow cathode are available. AAS can be used to measure a total of 61 metal metal.
The light source is a light source in AAS from cathode lamp derived from the element being measured is then passed into the flames that contain samples that have been atomized, then to the radiation passed through a monochromator to a detector. Chopper used to distinguish radiation from sources of radiation, and radiation from the flame. The detector will reject the direction of the direction of the current (DC) from the ignition and emission measure only alternating current from the source of radiation or samples.
Atoms of an element of the ground state will be subject to radiation then the atom will absorb the energy and cause the electrons in the outer shell up to a higher energy level or excited. If an atom is energized, then the energy will accelerate the movement of electrons that
electrons will be excited to a higher energy level and can return to its original state. The atoms of the sample will absorb some of the light emitted by the light source. The absorption of energy by atoms occur at specific wavelengths corresponding to the energy required by the atom.
Work 3.Cara AAS:
1. first gas in the open first, then the compressor and ducting, main unit, and a computer in order.
2. At the opening of SAA program (Spectrum Analyse Specialist), then comes the "if you want to replace the lamp cathode, click Yes if you want to change and if not No..
3. Selected yes to go into individual menu command, put numbers cathode lamps are mounted into the dialog box, then click setup, then cathode lamp socket will rotate towards the top of that new cathode lamps can be replaced or added with ease.
4. Selected No. if do not want to change a new cathode lamp.
5. In the program SAS 3.0, the selected menu element and working mode.Dipilih select elements to be analyzed by clicking directly on the desired element symbol
6. When you have finished click ok, then the condition settings screen appears. Arranged parameters are analyzed by setting fuel flow: 1.2; measurement; concentration; number of samples: 2; units of concentration: ppm; number of standard: 3; standard list: 1 ppm, 3 ppm, 9 ppm.
7. Clicked ok and setup, wait for it to finish warming up.
8. Clickable icon image burner / burners, as burners and lights ready tool used to measure the metal.
9. On the menu select measure sample measurements.
10. Inserted blank, ignored until a straight line is formed, then transferred to a standard of 1 ppm to data out.
11. Blanks inserted to straighten the curve, measured with the same steps for the standard 3 ppm and 9 ppm.
12. If the data is not good there will be no order for repeated measurements, measurement form, until the resulting curves and straight down.
13. Inserted into the sample 1 to curve up and turn a new measurement.
14. Put back blank and sample measurements to 2.
15. After the measurement is completed, the data can be obtained by clicking on the print icon in the menu bar or by clicking on the file and then print.
16. If the measurement has been completed, aspirasikan deionized water to rinse the burner for 10 minutes, the fire and light the burner is turned off, the program on the computer is turned off, then play unit AAS, then compressor, then ducting and gas last.
4.Bagian-section at AAS
a. Cathode Lamp
Cathode lamp is a light source at AAS. Cathode lamps have a life or a life of over 1000 hours. Cathode lamps on each element to be tested vary depending on the elements to be tested, such as Cu cathode lamps, only be used for the measurement of Cu element. Cathode lamps are divided into two types, namely:
Cathode Lamp Monologam: Used to measure one element
Cathode Lamp Multilogam: Used for measurement of several metals at once, it's just more expensive.
Socket on the black cathode lamp, which is used more prominently for easier installation cathode lamp when the lamp is inserted into the socket on the AAS. The black is the most prominent of the four other iron.
Cathode lamp serves as the light source to provide energy, so the element of metal to be tested, will be easily excited. Tape is added, so that there is no empty space for the passage of gas from the outside and the release of gas from the inside, because if there is gas coming out of the can cause toxicity to the surrounding environment.
How cathode lamp maintenance is when after use, the lights removed from the socket on the main unit of AAS, and the lights are put in place foam in a box again, and storage boxes closed. We recommend that after use, duration of use were recorded.
b. Gas Cylinder
AAS gas cylinders that are used on a gas cylinder containing acetylene gas. Acetylene gas in the AAS has a temperature range ± 20000K, and there are also gas cylinders containing N2O hotter than acetylene gas, with a temperature range of ± 30000K. regulator on the gas cylinder acetylene gas serves for setting the number to be issued, and the gas inside the tube. Speedometer on the right side of the regulator. Is a pressure regulator inside
tube.
Tests for detecting leaking gas cylinders or not, that is a close ear to the nearby gas regulator and given little water, to pengecekkan. When you hear the sound or the air, then menendakan that leaking gas cylinders and gas out there. Another thing you can do is to give a little soapy water on the top of the regulator and see if there are air bubbles are formed. If there is, then it is positive leaking gas cylinder.
Instead pengecekkan leak, do not use oil, because the oil will cause clogged gas line. Gas inside the tube to come out because it caused in the tube at the bottom of the tube containing acetone can be easy to make gas out, in addition to gas has pressure.
c. Ducting
Ducting is part of the chimney to suck the fumes or residue on the AAS, which is directly connected to the outside of the chimney on the roof of the building, so that the smoke generated by the AAS, not harmful to the environment. The smoke generated from burning the AAS, processed in such a way in the ducting, so that the resulting ppolusi harmless.
How maintenance ducting, ducting is by closing sections horizontally, so that the top can be sealed, so that no insects or other animals that can be entered into the ducting. Because if there is an insect or other animal that comes into the ducting, it can cause clogged ducting.
The use of ducting that is, pressing a small section on the ducting towards the side, as if straight horizontally, indicating ducting closed. Ducting serves to suck pembakara results that occurred in AAS, and expelled through the chimney connected to ducting
d. Compressor
The compressor is a separate tool to play unit, because this tool serves to supply air to be used by the AAS, at the time of burning atom. Compressor has 3 key regulator of pressure, which in part that the black box is the ON-OFF, spedo in the middle is the size of the air to be removed, or a function of pressure, while the right button to adjust the settings merupakantombol much / little air be sprayed onto the burner.
Section on the back of the compressor air is used as a storage area after the end of the use of AAS. This tool serves to filter the air from the outside, so bersih.posisi to the right, an open position, and position to the left meerupakan closed position. Water vapor is released, it will splatter and can lead to tight around the floor gets wet, therefore it should be the right time to push this section, should be accommodated with a cloth, so that the floor does not become soggy., And moisture will be absorbed into the cloth.
e. Burner
Burner is the most important unit in the game, because it serves as a place pancampuran burner acetylene gas, and aquabides, to mix evenly, and can burn the lighter properly and evenly. Holes are located on the burner, a cigarette lighter hole, where the hole is the beginning of the process pengatomisasian flame.
Care burner ie after the measurement is made, aspirator hose is inserted into the bottle containing aquabides for ± 15 minutes, it is the process of washing the aspirator and burner after use. Aspirator hose used to suck or siphon samples and standard solutions to be tested. Aspirator hose on the hose are colored orange on the right burner. While the hose is left, is the drain hose for acetylene gas. Metals to be tested is a metal in the form of the solution and must be diluted prior to use concentrated nitric acid solution. Metals that are in solution, will undergo excitation energy from low to high energy. Excitation value of each metal has a different value. The resulting flame color varies depending on the level of metal concentrations measured. When the color of red fire, then it indicates that too much gas. And the blue color of fire, is the best color of fire, and the heat, with a concentration
f. Exiles at AAS
Exiles on AAS stored in drigen and placed separately on AAS. Exhaust hose connected to the exhaust made a circle in such a way, so that the residue previously not climb back up, because if it happens to turn off the flame pengatomisasian during sample measurements, so that the resulting curve will look bad.
Place waste containers (drigen) placed on the board is also equipped with indicator lights. When the indicator light is lit, indicating that the tool or flame AAS on the pengatomisasian lit, and is the process pengatomisasian flame. In addition, the board also serves to place or not tersenggol foot container waste. When the waste is full, the contents in the container should not be made empty, but spared a little, so as not to dry.
5. Advantages AAS method
AAS method's advantages compared to regular spectrophotometers are specific, low detection limits of the same solution can measure different elements, direct measurement of the sample, the output can be read directly, fairly economical, can be applied to many types of elements, boundary determination extensive levels (from ppm to%). The disadvantage of the chemical effect which AAS are not able to describe the influence of a substance into atoms such as phosphate on Ca, the ionization effect is when atoms excited (not just dissociation) giving rise to emission at the same wavelength, as well as the influence of the matrix as a solvent.
Atomic Absorption Spectrophotometer (AAS) is a tool used in analytical methods for the determination of metallic elements and metalloids based on the absorption of radiation absorption by free atoms.
2. Basic Principles
Atomic absorption spectrophotometer (AAS) is a technique kuantitafif analysis of the elements of usage is very wide in many areas because the procedure is selective, specific, cost analysis is relatively inexpensive, high sensitivity (ppm-ppb), can easily create a matrix in accordance with the standards, analysis time is very quick and easy to do. AAS is generally used for elemental analysis, atomic absorption spectrophotometer single beam systems are also known and the double beam UV-VIS spectrophotometer withdrawal. Formerly known flame photometer that can only analyze the elements that can emit particularly groups IA and IIA elements. Generally light used is concave cathode lamps which its use only for the analysis of one element only.
AAS method the principle of absorption of light by atoms. The atoms absorb the light at a particular wavelength, depending on the nature of the element. Atomic absorption method just depends on the comparison and does not depend on temperature. Each tool AAS consists of three components, namely atomized units, sources of radiation, fotometerik measuring system.
AAS technique into a sophisticated tool in the analysis. This is because prior to the measurement does not necessarily require a separation of the elements is determined by the possibility of determining the presence of an element with another element can be done, provided the hollow cathode are available. AAS can be used to measure a total of 61 metal metal.
The light source is a light source in AAS from cathode lamp derived from the element being measured is then passed into the flames that contain samples that have been atomized, then to the radiation passed through a monochromator to a detector. Chopper used to distinguish radiation from sources of radiation, and radiation from the flame. The detector will reject the direction of the direction of the current (DC) from the ignition and emission measure only alternating current from the source of radiation or samples.
Atoms of an element of the ground state will be subject to radiation then the atom will absorb the energy and cause the electrons in the outer shell up to a higher energy level or excited. If an atom is energized, then the energy will accelerate the movement of electrons that
electrons will be excited to a higher energy level and can return to its original state. The atoms of the sample will absorb some of the light emitted by the light source. The absorption of energy by atoms occur at specific wavelengths corresponding to the energy required by the atom.
Work 3.Cara AAS:
1. first gas in the open first, then the compressor and ducting, main unit, and a computer in order.
2. At the opening of SAA program (Spectrum Analyse Specialist), then comes the "if you want to replace the lamp cathode, click Yes if you want to change and if not No..
3. Selected yes to go into individual menu command, put numbers cathode lamps are mounted into the dialog box, then click setup, then cathode lamp socket will rotate towards the top of that new cathode lamps can be replaced or added with ease.
4. Selected No. if do not want to change a new cathode lamp.
5. In the program SAS 3.0, the selected menu element and working mode.Dipilih select elements to be analyzed by clicking directly on the desired element symbol
6. When you have finished click ok, then the condition settings screen appears. Arranged parameters are analyzed by setting fuel flow: 1.2; measurement; concentration; number of samples: 2; units of concentration: ppm; number of standard: 3; standard list: 1 ppm, 3 ppm, 9 ppm.
7. Clicked ok and setup, wait for it to finish warming up.
8. Clickable icon image burner / burners, as burners and lights ready tool used to measure the metal.
9. On the menu select measure sample measurements.
10. Inserted blank, ignored until a straight line is formed, then transferred to a standard of 1 ppm to data out.
11. Blanks inserted to straighten the curve, measured with the same steps for the standard 3 ppm and 9 ppm.
12. If the data is not good there will be no order for repeated measurements, measurement form, until the resulting curves and straight down.
13. Inserted into the sample 1 to curve up and turn a new measurement.
14. Put back blank and sample measurements to 2.
15. After the measurement is completed, the data can be obtained by clicking on the print icon in the menu bar or by clicking on the file and then print.
16. If the measurement has been completed, aspirasikan deionized water to rinse the burner for 10 minutes, the fire and light the burner is turned off, the program on the computer is turned off, then play unit AAS, then compressor, then ducting and gas last.
4.Bagian-section at AAS
a. Cathode Lamp
Cathode lamp is a light source at AAS. Cathode lamps have a life or a life of over 1000 hours. Cathode lamps on each element to be tested vary depending on the elements to be tested, such as Cu cathode lamps, only be used for the measurement of Cu element. Cathode lamps are divided into two types, namely:
Cathode Lamp Monologam: Used to measure one element
Cathode Lamp Multilogam: Used for measurement of several metals at once, it's just more expensive.
Socket on the black cathode lamp, which is used more prominently for easier installation cathode lamp when the lamp is inserted into the socket on the AAS. The black is the most prominent of the four other iron.
Cathode lamp serves as the light source to provide energy, so the element of metal to be tested, will be easily excited. Tape is added, so that there is no empty space for the passage of gas from the outside and the release of gas from the inside, because if there is gas coming out of the can cause toxicity to the surrounding environment.
How cathode lamp maintenance is when after use, the lights removed from the socket on the main unit of AAS, and the lights are put in place foam in a box again, and storage boxes closed. We recommend that after use, duration of use were recorded.
b. Gas Cylinder
AAS gas cylinders that are used on a gas cylinder containing acetylene gas. Acetylene gas in the AAS has a temperature range ± 20000K, and there are also gas cylinders containing N2O hotter than acetylene gas, with a temperature range of ± 30000K. regulator on the gas cylinder acetylene gas serves for setting the number to be issued, and the gas inside the tube. Speedometer on the right side of the regulator. Is a pressure regulator inside
tube.
Tests for detecting leaking gas cylinders or not, that is a close ear to the nearby gas regulator and given little water, to pengecekkan. When you hear the sound or the air, then menendakan that leaking gas cylinders and gas out there. Another thing you can do is to give a little soapy water on the top of the regulator and see if there are air bubbles are formed. If there is, then it is positive leaking gas cylinder.
Instead pengecekkan leak, do not use oil, because the oil will cause clogged gas line. Gas inside the tube to come out because it caused in the tube at the bottom of the tube containing acetone can be easy to make gas out, in addition to gas has pressure.
c. Ducting
Ducting is part of the chimney to suck the fumes or residue on the AAS, which is directly connected to the outside of the chimney on the roof of the building, so that the smoke generated by the AAS, not harmful to the environment. The smoke generated from burning the AAS, processed in such a way in the ducting, so that the resulting ppolusi harmless.
How maintenance ducting, ducting is by closing sections horizontally, so that the top can be sealed, so that no insects or other animals that can be entered into the ducting. Because if there is an insect or other animal that comes into the ducting, it can cause clogged ducting.
The use of ducting that is, pressing a small section on the ducting towards the side, as if straight horizontally, indicating ducting closed. Ducting serves to suck pembakara results that occurred in AAS, and expelled through the chimney connected to ducting
d. Compressor
The compressor is a separate tool to play unit, because this tool serves to supply air to be used by the AAS, at the time of burning atom. Compressor has 3 key regulator of pressure, which in part that the black box is the ON-OFF, spedo in the middle is the size of the air to be removed, or a function of pressure, while the right button to adjust the settings merupakantombol much / little air be sprayed onto the burner.
Section on the back of the compressor air is used as a storage area after the end of the use of AAS. This tool serves to filter the air from the outside, so bersih.posisi to the right, an open position, and position to the left meerupakan closed position. Water vapor is released, it will splatter and can lead to tight around the floor gets wet, therefore it should be the right time to push this section, should be accommodated with a cloth, so that the floor does not become soggy., And moisture will be absorbed into the cloth.
e. Burner
Burner is the most important unit in the game, because it serves as a place pancampuran burner acetylene gas, and aquabides, to mix evenly, and can burn the lighter properly and evenly. Holes are located on the burner, a cigarette lighter hole, where the hole is the beginning of the process pengatomisasian flame.
Care burner ie after the measurement is made, aspirator hose is inserted into the bottle containing aquabides for ± 15 minutes, it is the process of washing the aspirator and burner after use. Aspirator hose used to suck or siphon samples and standard solutions to be tested. Aspirator hose on the hose are colored orange on the right burner. While the hose is left, is the drain hose for acetylene gas. Metals to be tested is a metal in the form of the solution and must be diluted prior to use concentrated nitric acid solution. Metals that are in solution, will undergo excitation energy from low to high energy. Excitation value of each metal has a different value. The resulting flame color varies depending on the level of metal concentrations measured. When the color of red fire, then it indicates that too much gas. And the blue color of fire, is the best color of fire, and the heat, with a concentration
f. Exiles at AAS
Exiles on AAS stored in drigen and placed separately on AAS. Exhaust hose connected to the exhaust made a circle in such a way, so that the residue previously not climb back up, because if it happens to turn off the flame pengatomisasian during sample measurements, so that the resulting curve will look bad.
Place waste containers (drigen) placed on the board is also equipped with indicator lights. When the indicator light is lit, indicating that the tool or flame AAS on the pengatomisasian lit, and is the process pengatomisasian flame. In addition, the board also serves to place or not tersenggol foot container waste. When the waste is full, the contents in the container should not be made empty, but spared a little, so as not to dry.
5. Advantages AAS method
AAS method's advantages compared to regular spectrophotometers are specific, low detection limits of the same solution can measure different elements, direct measurement of the sample, the output can be read directly, fairly economical, can be applied to many types of elements, boundary determination extensive levels (from ppm to%). The disadvantage of the chemical effect which AAS are not able to describe the influence of a substance into atoms such as phosphate on Ca, the ionization effect is when atoms excited (not just dissociation) giving rise to emission at the same wavelength, as well as the influence of the matrix as a solvent.
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