Glossary

A calibration step that eliminates dark current and other background signals from the response of a spectrophotometer.

Adjustment of a spectrophotometer to register 100% transmittance with a blank in the light path.

A versatile chelating reagent; used in gravimetric analysis, in volumetric analysis as a protective reagent in atomic spectroscopy, and as an extracting reagent; also known as oxine. 

An accuracy measurement equal to the numerical difference between an experimental measurement and its true (or accepted) value.

A precision estimate based on the deviations between individual members in a set and the mean of that set.

The logarithm of the ratio between the initial power of a beam of radiation P₀ and its power after it has traversed an absorbing medium, P. A = log(P₀/P) = -log(P/P₀).

A process in which a substance is incorporated or assimilated within another. also, a process in which a beam of electromagnetic radiation is attenuated during passage through a medium.

A colored medium (usually glass) that transmits a band of the visible spectrum.

Processes in which radiation causes transitions in atoms and molecules to excited states. The absorbed energy is lost, usually as heat, as the excited species return to their ground states.

A plot of absorbance as a function of wavelength.