ICP (Inductively Coupled Plasma) and AAS (Atomic Absorption Spectroscopy) standards are reference materials used to calibrate instruments in elemental analysis. ICP standards typically consist of solutions with known concentrations of metals or other elements, ensuring accurate quantification in complex samples. AAS standards, similarly, are used to calibrate instruments for precise measurement of metal concentrations by absorption of light. Both standards help maintain the accuracy and reliability of results in environmental, pharmaceutical, and industrial testing.