Fujiwara test

The Fujiwara test is used to determine whether a membrane has been oxidized by exposure to halogens. The test measures the presence of halogenated organics in a membrane sample. The test involves a small piece of membrane placed in the bottom of a test tube. One drop of 5N sodium hydroxide solution and 2 drops of a pyridine solution are added to the test tube. The tube is then placed in a water bath at about 90 C, and held there for 30 seconds. A positive test occurs when the pyridine layer in the test tube shows a red or pink color. Note that prolonged heating of the sample will cause the color to fade or turn to brown/yellow. This in an 

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Trichloro-compounds—Fujiwara test. To 1 ml of urine add 1 ml of sodium hydroxide solution and 1 ml of pyridine, and heat in a boiling water-bath for 2 minutes. The development of a red colour in the pyridine layer indicates ingestion of a trichloro-compound. A blank urine sample and an authentic solution of trichloroacetic acid should be tested at tile same time, both blank and control solutions being treated in similar fashion to the sample, because contamination of the atmosphere with laboratory reagents may give positive results. 

V.Trichloro-compounds—Fujiwara test. Carry out the test as described for urine (above) using a suitable volume of the filtered sample. 

The following tests, details of which are given on p. 4, should be performed Trinder s test for salicylates, cresol-ammonia test for paracetamol, FPN reagent for phenothiazines, Fujiwara test for trichloro-compounds, and the dithionite test for paraquat and diquat. In addition, the content of alcohol should be determined by gas chromatography (p. 19). 

This sample should be examined visually for colour and the presence of tablet residues or excipients (often maize starch). The odour should be noted as tiiis may indicate the presence of alcohols, aldehydes, ketones, phenols, cyanide, ethchlorvynol, nicotine, etc. The following tests, details of which are given on p. 5, should be performed Trinder s test for salicylates, cresol-ammonia test for paracetamol, FPN reagent for phenothiazines, Fujiwara test for trichloro-compounds, and the diphenyl- nine test for oxidising agents. In addition, tiie Reinsch Test for heavy metals (p. 57) should be carried out, and a diluted, filtered extract examined by direct ultraviolet spectrophotometry for drugs with highyl values. 

Apply the Fujiwara Test for trichloro-com-pounds (p. 135). The aqueous layer in this test can be used to test for the presence ofoxalate (p. 67). 

In addition, many odier tests described on pp. 129-147 may be used for pesticides, especially Aromat-icity (Method 2), Diphenylamine Test, Fujiwara Test, Koppanyi-Zwikker Test, Liebermann s Test, Marquis Test, Methanolic Potassium Hydroxide, Palladiiun Chloride, Sodium Nihoprusside (Method 2), md Sulphuric Acid. Certain pesticides are included in die Tables of colours, where appropriate. A test for the presence of cholinesterase inhibitors... 

This sedative has been found on innumerable occasions in greyhounds and occasionally in horses. Although it can be detected by the Fujiwara Test, p. 135, the concentration in horse urine following its administration is extremely low, and gas chromatography should be used for confirmation (see monograph). 

Colour Tests. Fujiwara Test—red Palladium Chloride—black. 

Colour Tests. Fujiwara Test—red Palladium Chloride—black. Heat with a small amount of resorcinol in 2M sodium hydroxide—red. If the resorcinol is replaced by either alpha- or betanaphthol—blue. 

Note. Dicophane does not react to the Fujiwara Test. 

A. Specific ieveis. Blood, urine, or breath concentrations may document exposure but are rarely available and are not useful for acute management. Qualitative urine screening for chlorinated hydrocarbons (Fujiwara test) may be positive after massive overdose. 

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