Benzidine has been used since the 1850s as the reagent base for the production of a. Method 50, issue 2, dated 15 august 1994 page 3 of 5 6. The most vital feature of this manual is that it lists in alphabetical order the ordinarily used chemical reagents with their molecular formula and. Benzidine may be used as a reference material in procedures that. Add 10 ml of the benzidine solution, and shake until a clear solution is obtained. Most arylamines are powerful poisons to the bloodmaking system. Benzidine definition, a grayish, crystalline, slightly watersoluble, basic compound, c12h12n2, usually derived from nitrobenzene. Store refrigerated expiration date 1 week hydrogen peroxide 3% 1. Tetramethylbenzidine or tmb is a chromogenic substrate used in staining procedures in immunohistochemistry as well as being a visualising reagent used in enzymelinked immunosorbent assays. Dissolve 40 g of ceric ammonium nitrate in 100 m1 of warm dilute 2n nitric acid.
Tell a friend about us, add a link to this page, or visit the webmasters page for free fun content. Benzidine is a bladder carcinogen in multiple species, including humans, dogs, mice. Article views are the countercompliant sum of full text article downloads since november 2008 both pdf and html across all institutions and individuals. Only a very small portion of dissolved benzidine will pass into the air. Improved benzidine sugar reagent for paper chromatograms. Benzidine can be used in studies on its mechanisms of genotoxicity. The properties of concern section shows echaassigned graphical indicators for certain substance properties that are regarded as being of relevance or importance to human health andor the environment based on the information provided to the agency. Ntp, 1992 national toxicology program, institute of environmental health sciences, national institutes of health ntp. Offhand, i cant remember what reactions benzidine was. Benzidine definition of benzidine by medical dictionary.
Benzidine may be used as a reference material in procedures that analyze for benzidine. Other jurisdictions such as the european union eu and the united states have taken or proposed actions to manage the risks posed by some of these substances. The overall composition of the mixture corresponds to that of hexathionic acid but. Exposure to benzidine based dyes are of concern to consumers, workers and children because benzidine dyes can be converted in the body into a chemical that is known to cause cancer. Recommended for elisa microwell procedures, not recommended for membrane applications. Benzidine is a grayishred, yellowish or white colored, very toxic, crystalline aromatic amine that darkens when exposed to air and light. Benzidine is prepared in a two step process from nitrobenzene. To ascertain whether a sample is suitable, prepare the reagent as described, place 2 cc. Please see the following for information about the library and its accompanying search. Benzidine test medical definition merriamwebster medical. In case of presence of blood appears blue or green staining fig.
It is done for the detection of blood in the stool that is not visible on gross inspection. Benzidine has not been imported into the united states in recent years. The azo dyes derived from benzidine are important because, unlike simpler classes of azo dyes, they become strongly fixed to cotton without a mordant. It needs to be freshly prepared in order to obtain best results, otherwise, possible contamination may occur. Benzidine has been linked to bladder and pancreatic cancer. In handbook of experimental pharmacology cs cooper and pl. Benzidine hydrochloride solution reagent for sulphate article no. Thus, for 4metho3hydraobenzene, benzidine cannot be formed and diphenyline is not formed as the pa position of a is substituted. Get a printable copy pdf file of the complete article 1. High chronic doses cause congestion of the spleen and tumor formation. View indentification, hazards, safety information, toxicity, regulations. Benzidine dihydrochloride is a white crystalline powder.
Benzidine is a member of a large class of carcinogens referred to as aromatic amines. The azo dyes derived from benzidine are important because, unlike simpler classes. Tmb is degraded by sunlight and by fluorescent lights. Benzidine test its principle, reagents and procedure. For endpoint assays the reaction may be stopped with acid, forming a yellow reaction product that may be read at 450 nm. Measure out 10 ml glacial acetic acid and add to the tmb 4. First, the nitrobenzene is converted to 1, 2diphenylhydrazine, usually using iron powder as the reducing agent. Exposure because benzidine may be produced only for captive consumption. Cdc niosh pocket guide to chemical hazards benzidine. Product name benzidine product number fb18197 synonyms. It is a crystalline sandy or sugarlike solid that may be grayishyellow, white, or reddishgray.
This article is within the scope of wikiproject occupational safety and health, a collaborative effort to improve the coverage of articles related to occupational safety and health on wikipedia. Develops a soluble blue reaction product that may be read at 370 or 655 nm. Benzidine rearrangement the conversion of hydrazobenzene i by the action of dilute mineral acids into 4,4diaminodiphenyl, or benzidine ii. Is hypergolic with red fuming nitric acid ntp, 1992.
The hazard fields include special hazard alerts air and water reactions, fire hazards, health hazards, a reactivity profile, and details about reactive groups assignments and potentially. Benzidine has been widely used for the detection of blood and as a reagent in the manufacture of dyes. Drexler, in the leukemialymphoma cell line factsbook, 2001. Diaminobiphenyl is an environmental genotoxin that posses increased risks of cancer to exposed people. Benzidine iii update statement toxicological profiles are revised and republished as necessary, but no less than once every three years. The carcinogenic nature of benzidine was discovered in the context of bladder cancer. Benzidine definition of benzidine by merriamwebster.
Pdf the nature of the sample in a forensic case is one of the most important factors, since it. What happens when a benzidine test is used for blood. I as an example of the general procedure employed in the prepa ration and use of the reagents of various concentrations, the following may be cited. Benzidine was one of the first chemicals for which an association of occupational exposure and increased incidence of urinary bladder cancer in humans was reported. May be incompatible with isocyanates, halogenated organics, peroxides, phenols acidic, epoxides, anhydrides, and acid halides. Turn the filter sample side down and place the beaker in an ultrasonic bath for 15 min. The resulting solutions contain moderate to high concentrations of hydrogen ions and have phs of less than 7. Why should benzidine reagent be freshly prepared answers. Benzidine cancercausing substances national cancer. Learn about benzidine, exposure to which raises your risk of bladder cancer.
Benzidine hydrochloride solution, laboratory chemicals by loba chemie, india. Benzidine has been used since the 1850s as the reagent base for the production of a large number of dyes, particularly azo dyes for wool, cotton, and leather. After two hours the sensitivity of this reagent was reduced to 1 in 40,000. It is important to add the hydrogen peroxide benzidine glacial acetic acid solution before preparing the stool suspension. Benzidine reagent in paper chromatography analytical. An evaluation of the benzidine test for occult blood in. Ingestion of benzidine causes cyanosis, headache, mental confusion, nausea and vomiting.
The mechanism of benzidine formation from hydrazobenzene has been the subject of incessant consideration1. Benzidine as a peroxidase reagent for blood smears and. Benzidine trivial name, also called 1,1biphenyl4,4diamine systematic name, is an organic compound with the formula c 6 h 4 nh 2 2. The reagents comprise a dry mixture of a 3, 3, 5, 5 tetramethylbenzidine and an alkali metal perborate, such as sodium perborate, and preferably also including a strong organic carboxylic acid such as citric acid and a. Treatment of this hydrazine with mineral acids induces a rearrangement reaction to 4, 4 benzidine. In the past, benzidine was used to produce dyes or products used in clinical laboratories. Jan 10, 2020 the fecal occult blood test fobt is a simple, inexpensive and most frequently performed chemical screening test on feces. Prepare a series of working standards in the range 0 to 20 g benzidine100 ml urine. He received his masters degree from the university of lucknow in. Dyes metabolized to benzidine dyes metabolized to benzidine benzidinebased dyes were considered by a previous iarc working group in 2008 iarc, 2010.
Barfoeds test is a chemical test used for detecting the presence of monosaccharides. Dyes metabolized to benzidine dyes metabolized to benzidine benzidine based dyes were considered by a previous iarc working group in 2008 iarc, 2010. Take 3 ml of fresh benzidine reagent in a test tube. Mix 18 ml of redistilled pyridine, 12 ml of water, and 3 ml of cone. Jan 21, 2015 benzidine salts can dissolve more easily in water than free benzidine.
Benzidine test definition of benzidine test by medical. In 1980, the last year for which an estimate was found, u. Kinetic study2 has shown the reaction to be bimolecular in respect of acid. Section 3 composition information on ingredients hazard ratings. Two serious disadvantages of benzidine as a reagent for sulphate are the. The benzidine rearrangement is widely used in the production of azo dyes and to obtain tolidine, dianisidine, and so on. Benzidine has been widely used for the detection of blood and as a reagent in the.
The nature of the sample in a forensic case is one of the most important factors, since it determines the posterior analysis, helping to define or discard its identity like blood versus. Visit chemicalbook to find more benzidine92875 information like chemical properties,structure,melting point,boiling point,density,molecular formula. Benzidine hydrochloride solution laboratory chemicals. However, benzidine has not been sold in the united states since the mid1970s. Department of health and human services public health service agency for toxic substances and disease registry. Us4673654a composition for determining peroxidaselike. Sigmaaldrich offers a number of benzidine products. When only small amounts of blood being passed in the feces, the blood or its breakdown products is not recognized and is. In common with benzidine some other aromatic amines such as 2aminonaphthalene have been withdrawn from use in almost all industries because they are so carcinogenic in the past a. The benzidine rearrangement is claimed to be an example of the quite rare 5,5 sigmatropic migration, which is a tenelectron homologation of the very common 3,3. It is based on the reduction of copperii acetate to copperi oxide cu 2 o, which forms a brickred precipitate.
Of course, a manual of this scope can not, and is not intended to, provide indepth infor. Related derivatives are used in the production of dyes. The following chemicals are required to perform benzidine test. Benzidine is listed as a hazardous constituent of waste. In the past, benzidine was used to produce dyes or products used in. The invention provides a reagent composition for detecting peroxidaselike activity in aqueous media, particularly for determining occult blood in fecal matter inthebowl. This is the listing and nsrl for benzidine and its salts. Benzidine exists in the air as very small particles or as a vapor, which may be brought back to the earths surface by rain or gravity. Benzidine, an organic chemical belonging to the class of amines and used in making numerous dyestuffs. Full text full text is available as a scanned copy of the original print version. Pdf handbook of chemistry lab reagent researchgate. Benzidine c12h12n2 cid 7111 structure, chemical names, physical and. Benzidine chemical agents and related occupations ncbi.
Neutralizes acids in exothermic reactions to form salts plus water. The mining chemicals handbook was originally little more than a directory of our products but, over the years, has evolved into a respected manual for use by engineers and plant operators in solving a variety of mineral processing problems. A compound used mainly for dyeing textiles and paper that is a known human carcinogen cancercausing agent. All mass spectra in this site plus many more are available from the nistepanih mass spectral library. Blood tests at the scene of crime northwestern university. Tmb is a white solid that forms a pale bluegreen liquid in solution with ethyl acetate. Benzidine is a white, grayishyellow, or slightly reddish crystalline solid or powder. When benzidine itself was found to be a class c carcinogen, the substituted 3,3,5,5tetramethyl benzidine compound was used, but gave a slightly slower reaction. Download msdsmaterial safety data sheet of benzidine hydrochloride solution. Urine and gastric juice should be filtered through a paper filter, and then to put on it reagent. Handbook of environmental data on organic chemicals.
For this reagent it is essen tial to use a good grade of benzidine. Three azo dyes metabolized to benzidine, direct black 38, direct blue 6, and direct brown 95 were considered by iarc working groups in 1982, 1987, and 2008 iarc, 1982, 1987, 2010. Some benzidine rearrangements are indeed thought to go through the 3,3 route. An obsolete colourimetric test once used to detect heme haemoglobin, myoglobin and related pigments, which fell into disfavour due in part to benzidine s carcinogenic potential. Benzidine forms insoluble salts with sulfuric acid. These dyes also have the potential to separate from textiles, such as clothing, that are in prolonged contact with human skin, increasing exposure risks. The benzidine rearrangement is claimed to be an example of the quite rare 5,5 sigmatropic migration, which is a tenelectron homologation of the very common 3,3 sigmatropic reaction e. A meta description is an html tag in the html code of your website, which allows you to customize a section of text that describes the page itself. Benzidine definition is a crystalline diamine base c12h12n2 prepared from nitrobenzene and used especially in making dyes.