Visual detection of cyanide using ninhydrin coated paper

Area of Science:

• Analytical Chemistry
• Food Safety
• Environmental Monitoring

Background:

• Cyanide exposure is a significant public health concern, primarily through contaminated water and consumption of cyanogenic plants like cassava.
• Existing cyanide detection methods often lack the safety, affordability, and ease-of-use required for untrained individuals or field applications.

Purpose of the Study:

• To develop a simple, safe, and cost-effective method for the visual detection of cyanide.
• To evaluate the utility of ninhydrin-impregnated paper for semi-quantitative cyanide analysis.
• To assess the potential of this method for monitoring cyanide release from food sources in real-world settings.

Main Methods:

• Whatman paper was coated with ninhydrin.
• The ninhydrin-coated paper was exposed to basic cyanide solutions.
• Colorimetric changes were observed and correlated with cyanide concentrations.
• The stability of the test paper and its application in monitoring cyanide release from processed cassava leaves were investigated.

Main Results:

• Ninhydrin-coated paper exhibited an immediate color change from pale yellow to red upon exposure to cyanide.
• The test allowed for visual, semi-quantitative detection of cyanide at concentrations up to approximately 5 μg/mL.
• The ninhydrin paper demonstrated good storage stability for several months.
• The method successfully monitored cyanide release during the processing of cassava leaves.

Conclusions:

• Ninhydrin-impregnated paper provides a practical and accessible tool for the visual detection of cyanide.
• This method holds significant potential for in-field monitoring of cyanide exposure, particularly in regions where cassava is a dietary staple.
• The developed test offers a valuable alternative to complex laboratory-based cyanide detection techniques for resource-limited settings.