Atomic Absroption Spectroscopy essays

Atomic Absroption Spectroscopy essays 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 anode is made of tungsten and the cylindrical cathode is made of the element of interest. This results in that a different lamp is required for each element t hat is to be analysis, but it is possible to buy lamps which have cathodes made of multiple materials making it possible to analyze more than one element at a time. The EMR that is created from the lamp is focused on the sample compartment in a fine beam. In the sample compartment the sample is atomized, by either flame atomization or by electro thermal atomization. In the flame atomization the sample is introduced into laminar flow burner where the sample is mixed with the fuel and oxidant and introduced into the flame as a smooth (laminar) flow. The mixture t...