What is the principle of AAS?
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 Analyse AAS results?
This calculating method is true and works if your AAS result is given in ppb = microg/l. In your case 0.192 mg/l = your AAS result = 192 microg/l. Your final result will be AAS result * calculating factor = 192 * 200 = 38400 microg/kg = 38400 ppb.
Why Acetylene is used in AAS?
Because it gives a very high temperature: 2200-2400 ∘C. This is due to its high heat of combustion, around 1300 kJ/ mol. If still higher temperatures are required, as for Al, Si, Ti, etc., a combination of acetylene and N2O is used, which reaches 2600-2800 ∘C.
What are the types of AAS?
There are flame (F AAS), cold vapor (CV AAS), hydride-generating (HG AAS), and graphite furnace (GF-AAS) systems.
Is AAS qualitative or quantitative?
Atomic absorption spectroscopy (AAS) is a quantitative spectro-analytical procedure for the determination of chemical elements using the absorption of optical radiation by free atoms in the gaseous state (Welz and Sperling, 2008).
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.
Which fuel is used in AAS?
Typical gases used in AAS are Nitrogen and Argon.
Which flame is used in AAS?
air-acetylene flame
Flame atomizers The oldest and most commonly used atomizers in AAS are flames, principally the air-acetylene flame with a temperature of about 2300 °C and the nitrous oxide system (N2O)-acetylene flame with a temperature of about 2700 °C.
Which gas is used in AAS?
What is dry ash and wet ash?
Two major types of ashing are used: dry ashing, primarily for proximate composition and for some types of specific mineral analyses and wet ashing (oxidation), as a preparation for the analysis of certain minerals. Microwave systems are now available for both dry and wet ashing to speed the processes.
Why is HCL used in AAS?
ATOMIC FLUORESCENCE SPECTROMETRY A HCL is composed of a silica envelope that contains 1–5 Torr of argon or neon and two metal electrodes. HCLs are almost ideal line sources for AAS because of their high stability and narrow linewidth (0.002 nm), but their relatively low intensity is a disadvantage for AFS.