An atomic absorption spectrophotometer is a device that detects an element or substance by vaporizing it and measuring where it absorbs light in the spectrum. A black line at a specific part of the light spectrum is usually used to indicate measurements. A flame or a heated graphite tube can be used to operate the instrument. A cathode light tube, a prism or optical filter for wavelength selection, and a photo-detector are usually included. Experiment results are sometimes projected on a digital display, or a computer can be connected to the system.
When a material is heated, such as metal, it vaporizes. The vapor and the atomic absorption spectrophotometer are illuminated by a beam of light with a specific wavelength. When light is absorbed by atoms in a material, the intensity of the light can change. Heavy metals can be detected in the environment, such as in water, soil, or rocks, using a spectroscopy instrument like this. It can also be used in the production of semiconductors and petroleum and chemical plants.
A sample is vaporized in an atomic absorption spectrophotometer by a burner, which can be a flame or a heated tube, while light is shone through a cathode tube. The light passes through the flame and then through a monochromator component. This section’s lenses typically act as prisms to filter out a specific wavelength, as well as scattered light that could interfere with the measurement. A photomultiplier is then used to detect the light’s intensity. Traditionally, this was a vacuum tube-like device, but microchips and solid-state electronics have largely replaced it in 21st-century technology.
A computer with specialized software that can run on common operating systems is frequently used to control modern atomic absorption spectrophotometer instruments. Spectrophotometers are extremely sensitive to even the tiniest traces of materials. These instruments can detect metals in parts per million, with the addition of a graphite furnace increasing sensitivity to parts per billion.
Knowing how to read the results of an experiment is required when using an atomic absorption spectrophotometer. Software can calculate absorbance values based on spectral readings when a sample is run. These must usually be compared to previously generated calibration curves. Comparing the results to known values can aid in a better understanding of the test results. This instrument can directly identify about 70 elements, as well as various materials that may contain any combination of them.