POTASSIUM FERROCYANIDE AS A REAGENT IN THE 



MICROSCOPIC QUALITATIVE CHEMICAL ANALYSIS 



OF THE COMMON ALKALOIDS 



By Howard Irving Cole 



Chemist, Bureau of Science, Manila 



The division of organic chemistry of the Bureau of Science 

 is often called upon to determine the presence or absence of 

 habit-forming drugs in minute amounts of material, such as a 

 drop of liquid clinging to a syringe or a grain or two of powder 

 in an otherwise empty container. Obviously, color tests are 

 not feasible in such cases and recourse is had to microchemical 



reactions by which many tests can be made upon an exceedingly 

 small amount of sample. 



Descriptions of these tests are scattered throughout the liter- 

 ature. Wormeley's 1 classic on the microchemistry of poisons 

 contains many tests and beautiful etchings. The various types 

 of crystals formed by the reaction of such standard reagents 

 as platinum or gold chloride are well known, but not so much 

 attention has been paid to some of the less-common reagents. 

 Among these potassium ferrocyanide should hold a prominent 

 place. Behrens, 2 Grutterink, 3 Stephenson, 4 and others mention 

 the use of potassium ferrocyanide as a reagent, but none of them 

 gives a complete list of the alkaloids yielding characteristic 

 crystalline precipitates with this reagent. I have tested forty 

 of the common alkaloids 5 with potassium ferrocyanide. By 



1 Wormeley, T. G., Micro-chemistry of Poisons ed. 2 (1885). 



2 Behrens, H., Anl. zur mikrochemishe Analyse 3 (1896). 



3 Grutterink, A., Zeitschr. Anal. Chem. 51 (1912) 175. 



* Stephenson, C. H., Some Microchemical Tests for Alkaloids (1921). 



"The alkaloids tested were: Aconitine, apomorphine, arecoline, atropine, 

 berberine, /3-eucaine, brucine, caffeine, cinchonidine, cinchonine, cocaine, 

 codeine, coniine, curare, emetine, ergotinine, heroine, homatropine, hydras- 

 tine, hyoscyamine, morphine, narceine, narcotine, nicotine, novocaine, pa- 

 paverine, physostigmine, pilocarpine, piperazine, piperidine, piperine, qui- 

 nine, quinoline, scopalamine, sparteine, stovaine, strychnine, theobromine, 

 theophylline, veratrine. 



97 



