If you are searching for an Atomic Absorption Spectrophotometer provide, take a look at the Labmate Buyer’s Guide. For further information, read the article: Background Correction in AAS – Can You Really Trust It As Much As You Do? A lamp consisting of a metal cathode and an inert gas that can emit a line spectrum of specific wavelength used in atomic absorption spectrophotometry. It is however much more expensive and there can be a loss in sensitivity.Īlthough both are widely used, there is some debate about the efficacy of these background correction techniques. The Zeeman technique is considered more accurate because it can detect any kind of background absorption. Like in the Deuterium method, total absorption is measured with the magnetic field off and background absorption with it on. The Zeeman technique uses an alternating magnetic field to split the absorption line into three components. It is advantageous because it corrects high background levels and it requires only one light source, eliminating the issue of alignment. This correction technique is used mainly in graphite furnace atomic absorption. The background absorption is then automatically subtracted from the total absorption to give the correct atomic result.ĭeuterium background correction does have its limitations, yet it remains the most frequently used and inexpensive method. When the reverse is performed (deuterium on, HCL off), just the background absorption is recorded. When the HCL is on and the deuterium lamp off, the total absorbance is measured. Two separate lamps are used to determine levels of background absorption a hollow cathode lamp (HCL) and a deuterium lamp. It is effective in the wavelength range of 180nm – 320nm. This is the oldest and most popular correction technique, but it is also the least accurate. There are many ways to correct background absorption - this article looks at two of the most commonly used methods. Background correction is used to distinguish background absorption from elemental absorption, thus returning more accurate results. Known broadly as background absorption, issues like radiation scattering and molecular absorption can result in an incorrect measurement of the element content in a sample. What is Background Correction and Why is it Needed?Ī variety of background phenomena can interfere with the detector and influence the results. Since every element absorbs a unique wavelength this is an effective way to highlight which chemicals are in the sample. When it has been atomised it is then possible, using a detector, to see what light wavelengths (or radiation) it absorbs. To do this, the sample (blood, water, pharmaceutical drug, etc.) is first converted into individual atoms. For example, AAS may be used to detect toxic elements in human blood or to measure metal content in water.ĪAS can identify more than 70 elements. It is frequently used in the fields of biophysics, toxicology and pharmacology. Atomic absorption spectroscopy is an analytical technique used in chemistry to measure the levels of certain metals within a solution. Background correction is a process used in atomic absorption spectroscopy (AAS) to return more accurate results.
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