The detection of dicyanogen on the micro scale. A contribution to the chemistry of specific, selective and sensitive reactions

Spot Tests for Phenol Vapors and for Aromatic Compounds Containing Oxygen

“…1-and 2naphthol, resorcinol, pyrocatechol, oand p-phenylphenol, 1,2,4-benzenetriol, naphthalenediol, 2,7-naphthalenediol, tetrahydroxyanthraquinone, (2, 7). (2,6), (1,4), (1,5) naphtholsulfonic acids, ellagic acid, 4-amino-3-methylphenol, 1amino-2-naphtholsulfonic acid, 7-sulfo-8hydroxyquinoline, methyloxyquinoline, sulfosalicylic acid, tetrachlorohydroquinone, 2 -hydroxy -5 -chlorobenzaldehyde, 2,4-dihydroxyacetophenone, phydroxybenzaldehyde, salicylaldoxime, pentachlorophenol, 2,4-dihydroxybenzaldehyde, 4-hydroxybenzophenone, orcinol, gallic acid, phenolphthalein, fluorescein, phenetole, veratrole, 4propenylveratrole, safrole, isosafrole, anethole, 4 -phenoxybutyric acid, piperonal, rotenone, umbelliferone ethyl ether, narceine, emetine, m-phenetidine, 4 -methoxyoformylbenzenesulfonic acid, anisic acid, narcotine, and acetylsalicylic acid.…”

Determination of Free and Combined Formaldehyde Using Modified Chromotropic Acid Procedure Application to Determination of Piperine Content of Pepper

“…Measured at 580 mg, the absorbance of the reaction mixture diluted with concentrated sulfuric acid is about 10% higher than that obtained after dilution with water. A recent note by Feigl and Hainberger (9) states that the sensitivity of Eegriwe's qualitative test for formaldehyde (7) can be greatly increased by reaction under anhydrous conditions. With the experimental procedure above, a plateau of color intensity is apparently reached, beyond wrhich a substantial increase in the amount of sulfuric acid does not affect absorbance (Table I).…”