Chemists use atomic spectrophotometers to determine the concentration or identity of metallic species. The sample can be in liquid form before being placed in the analyzer. To complete the process, the chemist uses specific acids such as hydrochloric or nitric to extract the metallic ingredients of a sample in a process called digestion. Digestion does not affect the quality or analysis of the sample. When the sample is converted into liquid form, it enters the atomic spectrometer via a capillary tube whereby it is atomized or converted into a fine mist by a flame.
A light source, also known as a cathode lamp, blasts the misted sample. The light source energizes the atomic elements in the sample, which jump to excited states. The excited atoms release energy and fall back to ground states at different intervals of time. This quantized energy, which is involved in the absorption (AA) or emission (AE) process, corresponds with a fingerprint wavelength pattern used to identify a particular metal atom.
Atomic emission and atomic spectroscopy are used to analyze samples. Atomic emission spectroscopy measures the light intensity emitted by excited atoms, while atomic absorption spectroscopy measures the light gained by atomic absorption. The percentage is then compared to a calibration curve to analyze the amount of material in the sample.
Different applications of atomic spectroscopy
Due to its specificity, there are many applications of atomic spectroscopy. Let us look at the broad categories.
Biological analysis
The biological analysis includes food samples and human tissue samples. Atomic absorption spectroscopy is used in human tissue samples to analyze or determine the number of metal levels and other electrolytes within the human tissue. The human sample can be in the form of urine, blood, bone marrow, hair, nails, among different types of human tissue samples. Certain metal concentrations can be toxic to the human body, and atomic spectroscopy helps determine concentration levels of metals such as mercury.
In the food industry, it is used to analyze vegetables, animal feeds, and products. This analysis is vital to determine the metal concentrations that are detrimental to human consumption. A key consideration that should be taken in food analysis is a sampling. The food sample should be an accurate representation of what is being analyzed. Food analysis helps consumers know about the mineral and trace elements in foods to know if they are consuming an adequate amount.
Environmental and marine analysis
The marine analysis involves different types of water analysis, such as drinking water, seawater, and wastewater. But this is different from the biological analysis since laws govern environmental and marine analysis. Various components often analyzed in water include lead, mercury, copper, and nickel.
Geological analysis
The geological analysis involves mineral reserves and environmental research. During the study of rocks, preparations may include acid digestions or leaching. But if the sample needs to have the silicone content analyzed, acid digestion is not suitable in preparation. When analyzing mineral reserves, the method of atomic absorption spectroscopy used needs to be fast and versatile.
Conclusion
Atomic spectroscopy is useful in a wide range of applications, including industry and academic settings. Medical labs use it to detect metal concentrations in urine samples. Environmental specialists use it to detect metal pollutants in water and soil, pharmaceutical technologists use it to identify if a metal catalyst has been purified after a drug, and the mining industry uses it to detect the number of precious metals such as gold.
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