Dictionary > Specific absorption coefficient

Specific absorption coefficient

A factor that measures the absorbance of light per unit of path length (of the spectrophotometer cuvette, usually expressed in centimeter) and per unit of mass concentration (usually expressed in grams/liter)
Specific absorption coefficient is used in absorbance measurements. One of its applications in biology is for estimating the concentration, for example, of the chlorophyll pigment when the absorbance of the pigment sample is determined through a spectrophotometer1, and using the formula2,:
Concentration of Pigment (mg/L) = units/Specific Absorption Coefficient (L g-1 cm-1) *1000
The concentration of the pigment in a sample can be estimated when the specific absorption coefficient is known. To obtain the specific absorption coefficient, the pigment is first purified from contaminants and then dissolved in a specific solvent. After the pigment is purified, its absorbance is measured using a spectrophotometer. This value would then serve as the universal standard when quantifying pigment concentrations from absorbance measurements. 2

  • molar absorption coefficient


1Stewart, W. D. P.. “Chlorophylls: Analysis.” Algal physiology and biochemistry. Berkeley: University of California Press, 1974. 165-166. Print.

2“Absorbance Theory & Application.”Turnerdesigns.com. N.p., n.d. Web. 28 Feb. 2014. Turnerdesigns.com/t2/doc/appnotes/S-0075.pdf.

You will also like...

human brain structure
The Conscious & Unconscious Nervous System

This tutorial elaborates on how the nervous system works, particularly at the tissue level of the brain. There are three..

Pollution in Freshwater Ecosystems
Pollution in Freshwater Ecosystems

There are many environmental factors that arise due to the usage of water in one way or another and for every action tha..

Chemical effects on plant growth and development
Effect of Chemicals on Growth & Development in Organisms

Plants and animals need elements, such as nitrogen, phosphorus, potassium, and magnesium for proper growth and developme..

Biological Energy
ATP & ADP – Biological Energy

ATP is the energy source that is typically used by an organism in its daily activities. The name is based on its structu..

Biological Cell Defense
Biological Cell Defense

Organisms employ different strategies to boost its defenses against antigens. Humans have an immune system to combat pat..

Cell Respiration
Cell Respiration

Cell respiration is the process of creating ATP. It is "respiration" because it utilizes oxygen. Know the different stag..