Related Experiment Video
Updated: Jun 28, 2026
05:36
Quantifiable and Inexpensive Cell-Free Fluorescent Method to Confirm the Ability of Novel Compounds to Chelate Iron
Published on: February 23, 2024
Colorimetric determination of macrolide antibiotics using ferric ion
1Department of Chemistry, Miami University, Oxford, OH 45056, USA.
Talanta
|October 1, 1995
Summary
A new colorimetric method uses Fe(3+) to detect macrolide antibiotics like erythromycin in fermentation broths. This technique allows for direct analysis without prior separation steps.
Area of Science:
- Analytical Chemistry
- Pharmaceutical Analysis
- Spectrophotometry
Background:
- Macrolide antibiotics are crucial in treating bacterial infections.
- Accurate quantification of macrolides in fermentation broths is essential for quality control.
- Existing analytical methods may require complex separation steps.
Purpose of the Study:
- To develop a simple and direct colorimetric method for macrolide antibiotic quantification.
- To utilize the reaction between macrolides and Fe(3+) for spectrophotometric analysis.
- To establish a method applicable to fermentation broth samples.
Main Methods:
- Macrolide antibiotics (erythromycin, oleandomycin, spiromycin, tylosin) reacted with Fe(3+) in an acetic acid-sulfuric acid mixture.
- Formation of a colored product measured spectrophotometrically at 592 nm.
- Determination of molar absorptivity and detection limit for erythromycin.
Main Results:
- A colored product formed with macrolides and Fe(3+), exhibiting maximum absorption at 592 nm.
- Erythromycin showed a molar absorptivity of approximately 2900 L mol(-1) cm(-1).
- A detection limit of 5 µg/mL was achieved for erythromycin.
- Troleandomycin produced only a weakly colored product.
Conclusions:
- The developed colorimetric method is effective for analyzing erythromycin and tylosin in fermentation broths.
- The method allows for direct analysis without the need for prior separation.
- This spectrophotometric approach offers a simple and potentially rapid quantification technique for specific macrolides.
Related Concept Videos
01:19Precipitation Titration: Endpoint Detection Methods
In argentometric precipitation titrations, endpoints can be detected visually by the Mohr, Volhard, and Fajans methods. In the Mohr method, adding a soluble chromate indicator gives an initial yellow color to the analyte solution. As the titrant is added, the first excess of silver ions forms a red silver chromate precipitate, marking the endpoint. The solution pH should be maintained at about 8 by adding solid CaCO3.
In the Volhard method, a standard excess of AgNO3 is first added to the...
In the Volhard method, a standard excess of AgNO3 is first added to the...
01:18Effects of EDTA on End-Point Detection Methods
Different methods, such as visual observance of metal-ion indicators, spectroscopic techniques, and potentiometric methods, can determine the endpoint of an EDTA titration.
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a result, EDTA...
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a result, EDTA...
00:39Complexometric Titration: Overview
Complexometric titration involves the formation of a complex by reacting a metal ion with one or more ligands. A visual indicator often detects the end point of a complexometric titration. It is added to the metal solution before the titration, forming a stable metal–indicator complex and imparting color to the solution. As the titration approaches the equivalence point, the excess of the added ligand displaces the indicator from the metal–indicator complex, releasing the free indicator. The...
01:23Redox Titration: Iodimetry and Iodometry
Iodometry and iodimetry are analytical methods used to determine the concentration of oxidizing or reducing agents using iodine. In iodometric titrations, the oxidizing analyte solution is usually acidified and treated with an excess of iodide ions, which generates an equivalent amount of iodine in equilibrium with triiodide. The released iodine is subsequently titrated directly against a standardized reducing agent. As the dilute iodine color becomes pale yellow, a few drops of freshly...