Removal of Pigments 245 



Gridley {1951) Method of Removal 



Method 1: 



1 . Slides down to water. 



2. Bleach for 5 minutes in: 



acetone 50.0 ml. 



3% HoOo 50.0 ml. 



28-29% ammonia (cone.) 1.0 ml. 



or overnight in 5% aqueous ammonium sulfide (diluting 20% 

 analytical reagent 4:1). 



3. Wash thoroughly, running water: 15 minutes or longer. 



Method 2: 3% HoOo: 2 hours. 



Carbon 



Carbon (opaque black) usually appears in the lungs and adjacent 

 lymph nodes, sometimes in the spleen and liver. If it is necessary to 

 distinguish it from malarial pigment, iron, or some other pigment or 

 precipitate, carbon is black and is insoluble in concentrated sulfuric 

 acid, in which other pigments will dissolve. 



Hemosiderin 



This yellowish, bro^vnish, or greenish brown pigment resists 

 bleaching and does not dissolve in alkalis or acids. It can be identified 

 by Perl's test, page 233. 



Bile pigments 



These are yellowish green and resist bleaching, but can be con- 

 verted by H2O2, Lugol's solution, nitrous acid, or dichromates into 

 greenish biliverdin-emerald green. Use Lugol's solution (page 410): 

 6-12 hours. Decolorize Avith sodium thiosulfate. 



Glick (1949) does not consider this reliable, because of diffusibility 

 of the reactants. 



For extensive consideration of pigments and other organic sub- 

 stances, see: Glick {1949); Gomori {1952); Gurr {1958). 



