What Is Lambda Max?

By Roger Fleming
Light is separated into different colors to determine lambda max.

Lambda max is the wavelength at which the maximum fraction of light is absorbed by a solution. Lambda (?) is a Greek letter that scientists use as the symbol for wavelength.

Color and Energy

The absorbance of light gives solutions their color. The color and energy of light can be determined from its wavelength.

Light is Absorbed by Electrons

Electrons in atoms and molecules move around the nucleus in regions called orbitals or energy levels. An electron can move up to the next level if it is given the exact amount of energy required to be in the next level. Light can provide that energy.

Solvent Effects

When light is shone on a solution, some of the energy of light absorbed is affected by and transferred to the solvent. The light absorbance is spread out around a central maximum wavelength--lambda max.

Local Lambda Max

There is usually more than one absorbance peak for a substance. Each local absorbance peak may be referred to as a local maximum.

Lambda Max in the UV

Most solutions also do absorb, or solely absorb, ultraviolet (UV) light. The wavelengths most strongly absorbed typically occur in the UV. Often people refer to absorbance peaks of visible light as lambda max even when a stronger peak may occur in the UV region.

About the Author

Roger Fleming is a staff scientist with an international corporation. A graduate of Bowling Green State University with a Bachelor of Science degree in chemistry cum laude, Fleming has been published in scientific journals and holds several patents. He has been writing for internal company consumption for over 30 years. Fleming has personal experience with how aging and weight interplay with exercise regimens.