Formaldehyde test

E.G.C Clark s Isolation and Identification of Drugs (The Pharmaceutical Press, London) specifies a method for making "microtests of a "pedant drop or "microdrop. The sulfuric acid-formaldehyde testing of DMT, to illustrate, yields dull orange with a sensitivity of 1.0 meg. sensitivity, while the ammonium molybdate test yields blue going to green and then yellow with a sensitivity of 0.1 meg. 

Some of the more useful formaldehyde tests are summarised below. 

Type 1 sample in the air above the water, type 2 sample in the water, EN ISO 14 184 part 1 = Japan Law 112, part 2 = AATCC 112. BS 6806 part 3 is a slight modification of AATCC 112. BS 6806 part 2 is called a free formaldehyde test method, but it also covers released formaldehyde, caused by elevated reaction temperature and the use of concentrated sulfuric acid for the colour development before colorimetrical determination. 

Formaldehyde Test, Add ca 0.5g of the sample to ca 5ml of 80% H SO contained in a test tube, heat the mixt at ca 100° for 3mins and cool. Dilute to 20ml with w and add 10% NaOH until the soln is neutral or faintly acidic. Filter and add to the filtrate 5 drops of Methane Reagentfwhich is a 10% soln of 1,1-dimethyl -cyclohexan-3,5-dione, (CH3)2CgHg02, in 95% alcohol). A cloudiness settling in ca 5 mins to a fine ppc, is a positive test for RDX... 

Meperidine hydrochloride can be identified by virtue of its characteristic IR, UV, and X-ray spectra (see 2.1, 2.3 and 2.9b). The N.F. XII 5 describes a test (based on the formation of an orange red color when meperidine hydrochloride is reacted with sulfuric acid-formaldehyde test solution) which distinguishes meperidine hydrochloride from morphine and hydromorphone. The characteristic melting point (188 - 191°C.) of the picrate salt- - of meperidine is also useful as an identity test. 

Dilute the initial formaldehyde solution to around 5 g F for testing. Pipette 50 ml of 1 M sodium sulphite (Na SO,) into a 250 ml beaker. Add 2-3 drops of thymolphthalein indicator. Pipette 10 ml of the formaldehyde testing solution into the beaker. A blue colour appears. Titrate the solution with a 0.05 N standard sulphuric acid until the blue colour just disappears. Record the volume (ml) of the standard sulphuric acid used. Calculate the concentration of the fonnaldehyde testing solution ... 

Table III. Summary of Formaldehyde Test Data for Various Phenolic-Bonded Panel Products...

In the FTM-2 "Formaldehyde Test Method for Large Scale Test Chamber", the method allows a temperature correction factor to be applied to formaldehyde concentrations determined at temperatures other than the desired 25j 0.5 C. In addition, the states of Wisconsin and Minnesota allow temperature corrections of formaldehyde levels determined at temperatures other than 25 C for field complaint investigations. The temperature correction factors are based on the popular Berge Equation (25). 

Preliminary Formaldehyde Testing Results for the Residential Standards Demonstration Program," Bonneville Power Adminsitration, U.S. Department of Energy, Reiland, P. McKinstry, M. Thor, P., 1985. 

If the formaldehyde test is positive, heat a sample of the plastic with a 10% glycolic solution of potassium hydroxide (dissolve 10 g KOH in approximately 95 ml ethylene glycol). A smell of ammonia (confirmed by blue color of moist red litmus paper) indicates urea resins. Melamine resins do not... 

If the formaldehyde test is negative, cover a sample with nonaqueous sodium carbonate in a test tube and heat the tube until the material melts. 

Epoxy resins g acrylonitrile ive a positive reaction for phenol according to the Gibbs indophenol test (see Section 6.1.3) due to the presence of bisphe-nol. In contrast to the phenolic resins, however, the formaldehyde test with chromotropic acid (see Section 6.1.4) is negative. 

Dimethyl hydantoin-formaldehyde polymer formaldehyde testing 2,4-Diaminophenol hydrochloride formaldehyde, removal Hydrogen peroxide... 

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