Qualitative and quantitative methods of determination

A series of identification reactions are described in the literature for the qualitative analysis. 

The following section contains the chemical identification reactions of the Pharmacopoeias for povidone. Its molecular weight determines the sensitivity of the tests. 

An aqueous solution is mixed with a saturated solution of potassium iodide followed by o.i N iodine solution. A thick brown-red flocculent precipitate immediately forms. 

10 ml of l N hydrochloric acid and 2 ml of 10% potassium dichromate solution are added to 5 ml of 2% povidone solution in water. A yellow-orange precipitate forms. 

2 ml of dimethylaminobenzaldehyde reagent (0.2 g reagent + 20 ml ethanol absolute + 0.5 ml cone, hydrochloric acid decoloured with activated charcoal) and 2 ml of cone, sulfuric acid are added to 1 ml of a 2% aqueous solution of povidone. After 30 seconds, the solution is cooled. A persistent orange-pink coloration is obtained. 

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Beil 1.601.(326) [668-70] 2JH.A.Iddles C.E.Jackson, AnalChem 6,454-6(1936) (Precipitation of acetaldehyde as hydrazone using 2,4-dinitrophenylhydrazine as a reagent) 3)Kirk Othmer l(1947),38(Qualitative and quantitative methods of determining acetaldehyde) 4)Jacobs(1949),476—8(Qualitative and quantitative methods of detn 5 Ullmanu 3 0953),11... 

Kirk Othmer l(1947),38(Qualitative and quantitative methods of determining acetaldehyde) 4)Jacobs(1949),476—8(Qualitative and quantitative methods of detn) 3)llllmann 3... 

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