Chemical Differentiation between Nicotinic Acid and Nicotinamide

Pharmaceuticals and Natural Drugs

“…The fact t,hat the reaction product LT-ith nicotinic acid gives approsimately twice the color as it does lyith an equivalent, amount of nicotinamide is the basis for a quantitative method for evaluating mixtures of nicotinamide and nicotinic acid (181). The fact t,hat the reaction product LT-ith nicotinic acid gives approsimately twice the color as it does lyith an equivalent, amount of nicotinamide is the basis for a quantitative method for evaluating mixtures of nicotinamide and nicotinic acid (181).…”

Food

“…This method is based on using sulfanilic acid or Tobias acid as coupling compounds instead of metol, ammonia, and aniline. Chemical differentiation between nicotinic acid and nicotinamide is based upon treating the sample with a 10% aqueous solution of cyanogen bromide and coupling the reaction products with sulfanilic acid (175). Absorbancy of the color given by nicotinic acid is about twice that given by nicotinamide at 430 µ. ACTOS Mixtures of different organic acids have been determined by means of the "chromatopack" (a pack of Whatman No.…”

Light Absorption Spectrometry

“…Development of colorimetric methods for organic substances has become a major problem in analytical chemistry, both because of the number of different substances and because of their importance. Examples of such systems, wdth recommended reactants, follow: epihydrin treated wdth phloroglucinol (74)'• butylated hydroxyanisole with 2,6-dichloroquinonechlorimide (176); 2, ;i, 5, -tetrachloronitrobenzene with acetone (plus tetraethyhunmonium hydroxide) (11); hydrolyzed vitamin B12 benzoylated and treated with acetylacetone (42); nicotinic acid wdth cyanogen bromide (102) or sulfanilic acid (260); 4-aminophenoi diazotized and coupled wdth resorcinol or reacted with 4-dimethjdnminobenzaldehyde (25); a method for cytochrome oxidase based on rate of oxidation of cytochrome c (65); vitamin A wdth activated glycerol dichlorohydrin (1); organometallic compounds, such as phenyl mercuric acetate, wdth dithizone (186); parathion and dimethylparathion saponified to give 4-nitrophenoi (141); ascorbic acid reduced by peri-naphthindantrione (78); 2nitro-1 ,l-bis(p-chlorophenyl)alkanes wdth ferric chloride (133); sym-trinitrobenzene wdth sodium ethylate (66); pectic acid wdth carbazole (254); tryptophan wdthp-dimethylaminobenzaldehyde (252); oxalic acid by reduction to glycolic acid and reaction w ith 2,7-dihydroxynaphthene (216); methylamine wdth lactose in alkaline solution (207); carbonyl compounds with 2,4-dinitrophenylhydrazone (165); various pyridine homologs wdth a choice of three different reagents (116); uroporphyrin by direct measurement at specified wrave lengths (230).…”