Atomic absorption spectroscopy

In atomic absorption spectroscopy (AAS), the mineral composition of a sample is worked out from how free atoms absorb light. A monochromatic source of light at an element-specific absorption wavelength passes through the sample after atomization in a flame, furnace or other device, and the quantity of light absorbed is proportional to the element’s concentration. Food laboratories rely on AAS for heavy-metal screening and mineral analysis, making it a cornerstone of contaminant monitoring for lead, cadmium, and arsenic, and of nutrition-labelling verification for iron, zinc, calcium, and other minerals. Its sensitivity, selectivity, and relatively low cost keep it central to food analytical chemistry.