![]() ![]() The main sources of AAS interference present in water are particulates, metal ions, bacteria and organics. What Types of Contaminants in Water can Affect AAS Results? This is particularly true for GFAAS, which has detection limits at sub- ppb levels, making it essential that all water used during the analytical workflow is free from any elements or compounds that may interfere with the results. The high sensitivity of AAS techniques means that it is important that the water used to prepare blanks, standards and samples is free from contaminants that could impact on the accuracy and reliability of the results. A narrow carbon tube is used to atomize the sample instead of a flame, improving the sensitivity and limit of detection by the absence of spectral noise from the flame and ensuring that much more of the sample is atomized. GFAAS is a more sensitive method typically used for the detection of very low concentrations of metals (>1 ppb) in low volume samples. Graphite Furnace Atomic Absorption Spectroscopy (GFAAS) Despite these factors it has proved an excellent, robust technique for routine mental determinations. The main drawbacks of this technique are its limited sensitivity, its capability to only measure one element at a time and limited linearity. The metal ions are nebulized as a fine spray into a high temperature flame where they are reduced to their atoms which selectively absorb light from an element-specific hollow cathode lamp. Types Of AASįlame Atomic Absorption Spectroscopy (FAAS)įAAS is commonly used to determine the concentration of metals in solution in the parts per million (ppm) or parts per billion (ppb) ranges. This makes it suitable for use in a wide range of applications. The main advantages of AAS are that it is relatively inexpensive and easy to use, while still offering high throughput, quantitative analysis of the metal content of solids or liquids. It is also used in a clinical setting for the analysis of biological fluids, such as blood and urine. What Is AAS Used For?ĪAS is commonly used for trace metal analysis of a wide range of sample types in the environmental sciences, food and beverage, chemical and pharmaceutical sectors for impurity or contamination monitoring and quality control, as well as the rapid assessment of raw materials. The difference between the sample and the background absorption is then measured, and compared with the absorption of a series of standard solutions. The ground state free metal atoms are excited by a specific wavelength of light, with the amount of energy absorbed proportional to the number of atoms of that element in the sample. How Does Atomic Absorption Spectroscopy Work?ĪAS uses the absorption of light to determine the concentration of specific metal atoms in a solid or liquid by vaporizing the sample in a flame (FAAS) or graphite furnace (GFAAS). ![]()
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