The Colorimetric Estimation of Barbiturates

Colorimetric Estimation of Indoleacetic Acid.

The wide use of the auxin, indoleacetic acid, in physiological and biochemical experiments has promoted interest in methods for its colorimetric estimation. MITCHELL and BRUNSTETTER (1) have proposed both the nitrite and the ferric chloride-sulphuric acid tests for the quantitative estimation of indoleacetic acid (IAA) in aqueous solutions, basing their suggested procedures upon a study of opti...

Barbiturates.

The Colorimetric Estimation of the Hydrogen Ion Concentration of Blood.*

With the introduction of Cullen’s calorimetric method (1) of estimating the hydrogen ion concentration of blood serum or plasma, it seemed possible for every laboratoryto have a methodemploying minimum material and apparatus and yet secure reliable results. It is generally conceded that the results obtained by the method on normal human plasma or serum agree very well with the true pH as determ...

Modified procedures for the colorimetric estimation of arginine and histidine.

In the estimation of very small q-qantities of material there is no question that colorimetric is preferable to gravimetric analysis. The colorimetric method is generally quicker and simpler to carry out-an important factor when numerous analyses are involvedand it is not subject to the manipulative errors incurred in dealing gravimetrically with minute amounts of material. The method, however,...

An improved colorimetric method for the quantitative estimation of thymine.

The Hunter (1) procedure was originally developed for the calorimetric d&&ion of minute amounts of thymine. In this procedure thymine is coupled under air with p-diazobenzenesulfonic acid in carbonate solut.ion, and a red color is subsequently produced by the addition of sodium hydroxide and hydroxylamine. Thymine was determined by this means in hydrolysates of dcsoxypentose nucleic acids (DNA)...