Estimation of Aloe-Emodin and Aloins in Curacao Aloes

A Polarographic Study of Certain Anthraquinones1

“…This compound like the 2,7-compound gives waves of regular form in most buffers. Values of id were found to be proportional to concentration in buffers of pH 4 (acetate), 10 (ammonia) and 11 (tartrate). Presumably others could be used for quantitative work.…”

“…An explanation of the mechanism of this hindered reduction must await further physical and chemical studies. Quantitative results were found for solutions of various concentrations in buffers of f>H 4, 7 (phosphate), 10 (ammonia) and 11 (borax) as well as in 0.1 N potassium chloride.…”

“…The amounts of the emodin that diffused were measured by the colorimetric method of Stone and Furman. 10 The " Numbers correspond to those in Table II. 6 The stock solutions were frequently alkaline; see Table II.…”

“…The quantitative estimation of the majority of the anthraquinones is found to be possible over part of the pH range. In aqueous media buffers of high pH (9)(10)(11)(12) must be used to dissolve many of greater range of pH than the hydroxy-substituted compounds. In a few instances neither the halfwave potentials nor the value of id.…”

Pharmaceuticals and Natural Drugs

“…The estimation of aloins and aloe-emetine by polarographic procedure is outlined by Stone and Furman (190) and Stone (189), while the dropping mercury electrode has been the means used for determining copper in copper proteins by Ames and Dawson (8). The estimation of camphor and alcohol in spirit of camphor is accomplished by Plein and Poe (160) by determining the refractive index and specific gravity of the solution and referring to a preconstructed chart made from known concentrations of the ingredients.…”