Product code RXSOL-62-6047-111
Thioglycolate (thioglycolic acid) is used in water testing as a powerful reducing and complexing agent to measure both dissolved and total iron.
Thioglycolate (thioglycolic acid) is used in water testing as a powerful reducing and complexing agent to measure both dissolved and total iron. It works by reducing insoluble ferric iron (Fe³⁺) to ferrous iron (Fe²⁺) and binding with it to form a highly visible purple complex.
Thioglycolic acid is used for the reduction of iron(III) to iron(II), and for pH adjustment. Thus only one reagent is required for analysis.
Application
How the Thioglycolate Method Works
Reduction: Thioglycolic acid reduces oxidized ferric iron (Fe³⁺) into soluble ferrous iron (Fe²⁺).
Complexation: The ferrous iron reacts with the thioglycolate to form a purple or pink-colored ferrous thioglycolate complex.
Measurement: The intensity of the resulting color is directly proportional to the total iron concentration in the water sample
Typical Testing Procedure
- Color Comparison: After a brief waiting period (usually 3 to 5 minutes), the color of the sample is compared against a standard color chart or measured photometrically to determine the iron level in mg/L (or ppm).
Advantages and Limitations
- Interferences: The formulation used in many test kits is designed to minimize interferences from other heavy metals that might be present in the water sample
Dosage
Typical Testing Procedure
Sample Preparation: A measured water sample is placed into a test tube or flask.
Reagent Addition: Citric acid is often added first to prevent the precipitation of iron, followed by the thioglycolate indicator.
pH Adjustment: Ammonia is added to make the solution alkaline. This step is crucial for the colored complex to form.
Color Comparison: After a brief waiting period (usually 3 to 5 minutes), the color of the sample is compared against a standard color chart or measured photometrically to determine the iron level in mg/L (or ppm)
Color Comparison: After a brief waiting period (usually 3 to 5 minutes), the color of the sample is compared against a standard color chart or measured photometrically to determine the iron level in mg/L (or ppm)