Atomic Absroption Spectroscopy

A detailed Summary of Atomic Absroption Spectroscopy

Atomic Absorption Spectrophotometers

An atomic absorption spectrophotometer consists of many complex and integral pieces. These components work together to help determine the concentrations of many different elements in various products to a very precise and accurate value. The instrumentation can vary depending on the use the machine is designed for, and the amount of accuracy that is required.

There are four basic components of atomic absorption spectrophotometer. They are as follows: a narrow band source of EMR (electromagnetic radiation), the sample compartment where the sample is atomized, a monochromator which is used to isolate the certain wavelength of EMR you are interested in, and a detector which determines how much of the EMR was absorbed / scattered by the sample. The most common source used in atomic absorption spectroscopy (AAS) is a hollow cathode lamp (HCL). The HCL has two electrodes, an anode that is negatively charged, and a cathode having positive charge. This charge is a result of a large electrical potential across the electrodes. These electrodes are contained in a sealed glass tube filled with an inert gas such as argon or neon. This inert gas is to prevent the oxidization of the electrodes. The ano

Atomic absorption spectrophotometers are a very use full tool in today?s world. Where people want to now the content of almost everything they can, no matter how little there is. There is a lot more to this device then can be talked about in a short essay. The chemistry behind how this machines work and why they work is quite interesting.

The different types of atomic absorption spectrophotometer available on today market are quite large. The type of spectrophotometer to be use is based on the minimum amount functionality that is required. The minimum requirements are used because of the price of this machine. The starting point for a basic AA spectrophotometer is about twenty thousand dollars . That would be one would not half time in sample and half time in air. So the 100% transmittance reading would have to be manual set, then the difference in the reading would be used to determine the concentrations. This method is slightly less accurate then when a dual beam is used to split the time the EMR is going through the sample and reference air. As the experiment is being performed the air around the machine may change and with put the 100% transmittance reading out of calibration. The Dual beam system also has another used to get more accurate values. As the sample is atomized they may also give off EMR which will be collected by the detecting causing it to read a high transmittance of the EMR which it will think is from the source. So as the beam is not passing through the sample the signal that appears at the detector is subtracted from when the beam is passing through the sample. Another problem with AA is when the sample is atomized it is essential burned, if the sample contains some kind of organic material such as hydrocarbons, it will give off

Some common words found in the essay are:
EMR HCL, HCL HCL, Absorption Spectrophotometers, atomic absorption, flame atomization, sample compartment, sample atomized, absorption spectrophotometer, atomic absorption spectrophotometer, transmittance reading, electrical potential, graphite furnace, deuterium lamp, 100% transmittance, air 100% transmittance, beam passing sample, focused sample compartment, atomic absorption spectroscopy,

Approximate Word count = 1190
Approximate Pages = 5 (250 words per page double spaced)

Category: Science