What is the principle of atomic absorption spectroscopy?
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. Electrons in the atom move from the ground state to an excited state.
What are three common uses of atomic absorption spectroscopy?
Atomic absorption spectroscopy is utilized across many industries and is instrumental in the detection of metals within a sample. As such, this process is commonly utilized in pharmacology, archaeology, manufacturing, mining, and forensics.
What are the types of atomic absorption spectroscopy?
There are various types of AAS – Flame (F AAS), Cold vapour (CV AAS), Hydride-generating (HG AAS), and Graphite furnace (GF-AAS) systems.
Who discovered atomic absorption spectroscopy?
Alan Walsh was the originator and developer of the atomic absorption method of chemical analysis, which revolutionized quantitative analysis in the 1950s and 1960s.
Which cell is used in AAS?
There are two basic atom cells (a means of turning the sample, usually a liquid, into free atoms) used in atomic absorption spectroscopy: (i) the flame and (ii) electrothermal heating of a sample cell.
Why was AAS invented?
The concept of atomic absorption spectroscopy (AAS) came to CSIRO scientist Alan Walsh in a flash of inspiration as he was gardening at his Melbourne home. This led to an invention that has since been labelled as one of the most significant achievements in chemical analysis last century.
When was AAS invented?
The Beginnings of AAS. The basic principle of light absorption through atoms in their fundamental state was discovered and documented in 1860 by Kirchhoff and Bunsen. The discovery is considered to be the theoretical basis of AAS. However, the actual year of birth of AAS is seen as 1955.
What is chemical interference in AAS?
Chemical interference occurs when an analyte is not totally decomposed in flame. There is less atoms present, and therefore a reduced absorbance of the analyte.
Which flame is used in AAS?
Chromium is typically determined by flame AAS using an air-acetylene flame or a nitrous oxide-acetylene flame. Although chromium has a large number of resonance lines of similar sensitivity, the 357.9 nm line is most commonly used.
What is nebulizer in AAS?
Nebulizers. A nebulizer is a device that introduces a liquid sample into the AAS. Here, we will discuss the most common types: pneumatic and ultrasonic nebulizers. Pneumatic Nebulizers. A pneumatic nebulizer converts a sample solution into an aerosol of tiny droplets using a jet of compressed gas.
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.