Total and Free Sulfite Assay Kit

A rapid, simple, reliable and accurate method for the measurement and analysis of total sulfite (sulphite) and free sulfite in wine, beverages, food stuffs and other materials. Supplied as a “ready to use” liquid stable formulation that is suitable for manual, auto-analyser and microplate formats.

Suitable for manual, auto-analyser and microplate formats.

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Product Code
40 assays (manual) / 400 assays (microplate)
/ 400 assays (auto-analyser)

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Colourimetric methods for the determination of Total and Free
Sulfite in wine, fruit juice, food stuffs and other materials

The Total Sulfite assay is based on the reaction principle
between thiol groups and Ellman’s reagent

The Free Sulfite assay is based on the reaction principle of
SO2, fuchsin and aldehyde binding

Kit size:                            40 assays (manual) / 400 (microplate)
                                         / 400 (auto-analyser)
Method:                           Total sulfite: Spectrophotometric at 405 nm
                                          Free sulfite: Spectrophotometric at 575 nm
Total assay time:             Total sulfite: ~ 6 min
                                          Free sulfite: ~ 9 min
Detection limit:                Total sulfite: ~ 5.3 mg/L
                                          Free sulfite: ~ 2 mg/L
Application examples:
Wine, fruit juice, seafood, food stuffs and other materials
Method recognition:    
Validated for red and white wines at the Bundesamt für Weinbau, Austria.
Used widely in the wine industry


  • ”Ready to use" liquid stable Formulation 
  • Very competitive price (cost per test) 
  • All reagents stable for > 18 months 
  • Very rapid reaction 
  • Mega-Calc™ software tool is available from our website for hassle-free raw data processing 
  • Standard included 
  • Suitable for manual, microplate and auto-analyser formats
To choose a chapter, play the video and select the required chapter from the options on the video display.

Chapter 1: Introduction & Kit Description
Chapter 2: Theory of Assay Procedure
Chapter 3: Standards & Calibration Curves
Chapter 4: Preparation of the Single Point Standard
Chapter 5: Preparation of the Calibration Curve
Chapter 6: Assay Procedure
Chapter 7: Free Sulphite Calculations

Below you will find a link to our dedicated frequently asked questions section. Within this section you will find common questions and answers on a range of topics about the product.