An Improved Reflection Colorimeter Integrated with a Coaxial Optical-fiber Cable for Highly Sensitive Solid-phase...

Area of Science:

• Analytical Chemistry
• Environmental Monitoring
• Spectroscopy

Background:

• Nickel ion detection is crucial for environmental and industrial monitoring.
• Existing methods for nickel analysis can be complex, expensive, and require laboratory settings.
• There is a need for sensitive, portable, and user-friendly nickel detection techniques.

Purpose of the Study:

• To develop a highly sensitive solid-phase colorimetry method for nickel ion detection.
• To improve an existing reflection colorimeter for enhanced nickel analysis.
• To enable accurate on-site nickel ion quantification with minimal technical expertise.

Main Methods:

• Utilized an improved reflection colorimeter with a coaxial optical-fiber cable.
• Collected nickel complex with α-furil dioxime on a membrane filter within a disposable syringe filter unit.
• Connected the optical-fiber cable to the syringe filter unit via a Luer-lock fitting for direct color intensity evaluation.

Main Results:

• Achieved a highly sensitive detection limit of 0.8 ng for nickel ions (0.3 μg L^-1 in a 2.5 mL solution).
• Demonstrated accurate color intensity evaluation of the nickel complex on the membrane filter.
• Validated the improved configuration for reliable solid-phase colorimetry.

Conclusions:

• The improved solid-phase colorimetry method offers high sensitivity for nickel ion detection.
• The system is suitable for on-site analysis, requiring no expensive instrumentation or advanced laboratory skills.
• This approach provides a practical solution for rapid and sensitive nickel monitoring in various settings.