Quantitative Determination of Milnacipran by Simple Colorimetric Methods

Quantitative colorimetric determination of tryptophan.

The methods currently used for the estimation of tryptophan are based on one of the following principles: Reaction with aldehydes in acid solution (1, Z), with glyoxylic acid (3), with mercury salts and nitrous acid (4,5), by determination after isolation from its mercury salt (6)) or by the use of Marshal’s reagent (7). Of the above mentioned methods, those based on aldehyde reactions and on t...

Qualitative and quantitative colorimetric determination of heptoses.

All heptoses produce with orcinol in dilute HCl two characteristic colored compounds which differ greatly in their absorption spectra. Three different modifications of this reaction were found useful. Procedure i--To 2 cc. of a solution containing 20 to 100 y per cc. of ketoheptose or 5 times as much of an aldoheptose is added 0.4 cc. of concentrated HCl, sp. gr. 1.19, in a test-tube with a gro...

Determination of Oseltamivir Quality by Colorimetric and Liquid Chromatographic Methods

We developed a colorimetric and chromatographic assay for oseltamivir to assess the authenticity of Tamiflu (F. Hoffmann-La Roche Ltd., Basel, Switzerland) because of a growing concern about counterfeit oseltamivir. The colorimetric assay is quantitative and relies on an extractable colored ion-pair complex of oseltamivir with Congo red or bromochlorophenol blue. The reverse-phase chromatograph...

New Enzymatic Colorimetric Method for the Quantitative Determination of Phenylalanine in Dry-Blood Spots

Phenylketonuria (PKU) is an autosomal recessive disorder, which is characterized by severe mental retardation, microcephaly and seizures. The symptoms of this disease can be prevented if detected soon after birth. Therefore, blood Phenylalanine (Phe) measurement is essential for the early diagnosis, treatment and dietary monitoring of PKU patients. The goal of this research was to introduce a r...

A new simple semimicro method for colorimetric determination of urea.