ADRENALINE (EPINEPHRIN, ADRENINE) 91 



phate. Pancrazio [1909, 1910] has used the sodium salt and Ewins 

 [1910] the potassium salt. Ewins adds potassium persulphate 

 solution to the adrenaline solution until the concentration of the per- 

 sulphate is about o - i per cent, and then immerses the test tube for a 

 short time in a boiling water bath. Under these conditions a distinct 

 reaction is still obtained at a dilution of I : 5,000,000. The persul- 

 phate reaction for adrenaline seems therefore to be more delicate than 

 any other, with the possible exception of Bayer's modification of the 

 Frankel-Allers reaction (see above) for which an equal degree of 

 delicacy is claimed. According to Ewins potassium persulphate has 

 an additional advantage in the estimation of adrenaline in extracts of 

 the gland, since it discharges the colour of these extracts to a consider- 

 able extent, the colour interfering with the Bayer-Frankel-Allers test. 

 With persulphate a clean and distinct red tint results, which is per- 

 manent for a considerable time. 



D. Other oxidising agents which colour adrenaline solutions red, 

 are potassium ferri cyanide (Cevidalli [1908]), brown oxides of man- 

 ganese (Zanfrognini [1909]), sodium nitro-prusside and ammonia, 

 bleaching powder, chlorine, bromine, ammoniacal silver solutions, and 

 osmic acid (Mulon [1905]). According to Borberg [1912] all the 

 " red " colour reactions for adrenaline are similar and depend on the 

 formation of the same oxidation product. Borberg gives the limit as 

 I : 300,000, thus perhaps underestimating the sensitiveness of some 

 of the reactions. 



Ewins [1910] examined the effect of iodine and persulphate and 

 of the Comessatti, Frankel and Allers, and Bayer reagents on a 

 number of synthetic bases, closely related to adrenaline. He found 

 that aminoethanol-catechol '(arterenol), as well as dihydroxy-phenyl- 

 ethylamine and its N-alkyl derivatives (including epinine) give the 

 various reactions with about the same degree of sensitiveness as 

 adrenaline, but none of these reactions are given by ketone bases, such 

 as amino-aceto-catechol and its derivatives (including homorenon). 

 Among these synthetic bases there is therefore no close parallelism 

 between chemical reactivity and physiological action. 



E. Folin, Cannon and Denis [1912] have recently described 

 a new and very sensitive colour reaction for uric acid, which is 

 also given by adrenaline with three times as great a sensitiveness 

 (i : 3,000,000). One hundred grm. of sodium tungstate is dissolved 

 in 750 c.c. of water, and after adding 80 c.c. of 85 percent, phosphoric 

 acid, the solution is boiled gently for one and a half to two hours and 

 then made up to I litre ; 3^^ mg. adrenaline can be detected. 



