Biological determination is a method of measuring the amount of a chemical substance by the degree of its effect on some biological system.
This method is based on the ability of living organisms to respond to the presence and concentration of various chemical compounds. The response of a biological system, such as cells, tissues, or an entire organism, is used to quantify the presence of a test substance.
The sensitivity of the biological determination depends on the selected test object. For example, bacteria, yeast, algae, and crustaceans are often used to determine toxic substances. The reaction of these organisms makes it possible to accurately estimate the concentration of the toxicant.
Biological determination is widely used in analytical chemistry, toxicology, medicine, ecology and other fields for express analysis and monitoring of chemical compounds in environmental objects and biological fluids.