ON THE DETERMINATION OF ALDEHYDES IN 

 DISTILLED LIQUORS. 1 



By Mariano Vivencio del Rosario. 

 (From the Chemical Laboratory, Philippine Medical School, Manila, P. I. 



The eolorimetric method for the determination of aldehydes in dis- 

 tilled liquors, provisionally adopted by the Association of Official Agri- 

 cultural Chemists, 2 is based upon the action of aldehydes toward Scruff's 3 

 reagent. This method is identical with the one given by Tollman and 

 Trescott 4 which, in its turn, is a modification of the method extensively 

 used by Girard and Dupre. 5 



Two volumetric methods for the determination of aldehydes have 

 been proposed. Seyewetz and Gibello showed the possibility of titrating 

 formaldehyde and its polymers with a. solution of normal sodium sulphite 

 made neutral to phenolphthalein by a few drops of acid. The reaction 

 depends upon the fact that normal sodium sulphite, in the presence of 

 acid, is converted into sodium hydrogen sulphite which forms an addition 

 product with the formaldehyde. As long as the whole amount of formal- 

 dehyde has not been changed to the bisulphite combination, the solution 

 remains neutral in spite of the acid added. Seyewetz and Bardin G have 

 attempted to apply this method to aldehydes in general. 



The volumetric method of Ripper 7 is similar in principle and applica- 

 tion. The amount of aldehyde is calculated from the amount of po- 

 tassium bisulphite required to form the addition product as shown by 

 titration with standard iodine solution. 



1 Abstract of the thesis presented to the Ogden Graduate School, University 

 of Chicago, in candidacy for the degree of S. M. 



2 Bureau of Chemistry, U. S. Dept. Agric, 107, 96. 



3 Compt. rend. Acad. sci. (1865), 61, 45. Ibid., (1887), 105, 1182. Centralbl. 

 f. Chem. (1905), 1305. Moniteur Scientifique (1890), 893. Ch'.' Girard et 

 A. Dupre\ Analyse des Matieres Alimentaires. Paris: V Te Ch. Dunod & P. Vico. 

 (1894), 278. Ch. Girard et L. Cuniasse. Manuel Practique de 1' Analyse des Al- 

 cohols et des Spiritueux. Paris: Masson et C lc . (1899), 172. 



'Journ. Am. Chem. Soc. (1906), 28, 1624. 



5 Analysis of Potable Spirits, p. 30. 



"Bull. Soc. Chim. de Paris. (1905), 33, 1000. 



7 Monatsh. f. Chem. (1901), 21, 288. 



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