The benzidin test is a chemical procedure used in industrial and medical laboratories to detect substances that contain blood. The spelling of 'benzidin' is pronounced as \ˈbɛn.zɪ.diːn\ in IPA phonetic transcription, with emphasis on the second syllable. The correct spelling of this word is important, as any errors can lead to confusion and misinterpretation of test results. The benzidin test is commonly used to identify the presence of blood in urine or stool samples, which can indicate a range of medical conditions.
The benzidine test is a chemical test mainly used in the field of forensic science and pathology to detect the presence of blood in a given sample or on a surface. It is a simple and highly sensitive test that relies on the oxidation of benzidine by hydrogen peroxide in the presence of hemoglobin, resulting in a distinct blue-green color change.
To perform the benzidine test, a small amount of the suspected sample is mixed with a reagent solution containing benzidine and hydrogen peroxide. If blood is present, the hemoglobin in the blood catalyzes the oxidation reaction between benzidine and hydrogen peroxide, causing the solution to turn blue or green.
The benzidine test is considered highly reliable and has been widely used as a presumptive test for blood at crime scenes or in medical diagnostics. However, due to health and safety concerns associated with benzidine, which is a known carcinogen, alternative substances like orthotolidine or tetramethylbenzidine (TMB) have been recommended as replacement reagents.
In conclusion, the benzidine test is a chemical test used to detect the presence of blood based on the oxidation reaction between benzidine and hydrogen peroxide in the presence of hemoglobin. It is a sensitive and commonly used method in forensics and pathology, although substitutes are now preferred due to safety concerns.
For blood: the suspected fluid is treated with glacial acetic acid and ether, and the latter is then decanted and treated with hydrogen peroxide and a solution of benzidin in acetic acid; the presence of blood is indicated by a bluish color turning to purple.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The term "benzidine test" is derived from the compound "benzidine", which is a chemical reagent used in this particular test. The etymology of "benzidine" itself can be broken down as follows:
The word "benzidine" is composed of two elements: "benz-" and "-idine".
1. "Benz-" is derived from "benzene", which refers to a colorless, flammable liquid hydrocarbon compound. The term "benzene" comes from the German word "Benzin", meaning "benzine", which is a liquid compound derived from coal.
2. "-idine" is a suffix often used in chemistry to denote a class of organic compounds. It comes from the Greek word "idēs", meaning "offspring" or "descendant".