Related Experiment Video
Updated: Sep 13, 2026

A Colorimetric Method for Measuring Iron Content in Plants
Published on: September 7, 2018
Simple determination of high urinary excretion of 5-hydroxyindole-3-acetic acid with ferric chloride
Abstract:
We describe a method for determination of urinary 5-hydroxyindole-3-acetic acid, a metabolite of serotonin and tryptophan and a useful indicator of metastasizing carcinoid tumor. The analysis is based on the color development with ferric chloride added to the residue obtained on evaporating a diethyl ether extract of the sample that has been acidified with sulfuric acid and saturated with sodium chloride. The color is measured by 510 nm. The reaction was made highly specific by the acidification so that nonspecific reactions with catecholamines and with other phenolic compounds such as salicylic acid could be eliminated.
More Related Videos
08:23Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds
Published on: February 16, 2022
09:51TD-DFT Guided Advanced E-Eye Sensing Technique for On-site Quantification of Fe, Cr, F, and As in the Environmental, Biological, and Food Samples
Published on: September 19, 2025
Related Concept Videos
Qualitative Analysis
For instance, group IV...
Solution Composition During Acid/Base Titrations
The α0 and α1 values represent the...
Precipitation Titration: Endpoint Detection Methods
In the Volhard method, a standard excess of AgNO3 is first added to the...
Precipitation and Co-precipitation