Dictionary > Specific absorption coefficient

Specific absorption coefficient

Definition
noun
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)
Supplement
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
Compare:

  • molar absorption coefficient

Reference(s):

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...

Chromosome Mutations
Chromosome Mutations

Mutations can also influence the phenotype of an organism. This tutorial looks at the effects of chromosomal mutations, ..

Bryophytes
Bryophytes

Bryophytes (nonvascular plants) are a plant group characterized by lacking vascular tissues. They include the mosses, th..

Crossing Over and Genetic Diversity
Inheritance and Probability

Gregor Mendel, an Austrian monk, is most famous in this field for his study of the phenotype of pea plants, including ..

Transpiration
Water in Plants

The movement of molecules (specifically, water and solutes) is vital to the understanding of plant processes. This tuto..

Energy pyramid
Freshwater Community Energy Relationships – Producers & Consumers

This tutorial looks at the relationship between organisms. It also explores how energy is passed on in the food chain an..

Darwin's Finches - Natural Selection
Darwin and Natural Selection

This tutorial investigates the genetic diversity in more detail. It also delineates how certain alleles are favored over..

Related Articles...

No related articles found

See all Related Topics