Determination of Rhodamine 6G with direct immersion single-drop microextraction combined with an optical probe

Area of Science:

• Analytical Chemistry
• Spectrophotometry
• Environmental Monitoring

Background:

• Rhodamine 6G (Rh6G) is a widely used dye with potential environmental and health implications.
• Accurate and sensitive detection methods for Rh6G are crucial for monitoring its presence in various matrices.
• Existing microextraction techniques often involve multiple steps and may not be environmentally friendly.

Purpose of the Study:

• To develop a novel, sensitive, and green analytical method for rhodamine 6G determination.
• To combine preconcentration and spectrophotometric measurement into a single, efficient step.
• To evaluate the method's performance and applicability in real-world samples.

Main Methods:

• Direct immersion single-drop microextraction (DI-SDME-OP) coupled with an optical probe.
• Formation of an ionic associate between Rh6G and picric acid at pH 3.0.
• Extraction using amyl acetate and online spectrophotometric monitoring at 534 nm.

Main Results:

• The DI-SDME-OP method demonstrated high sensitivity with a limit of detection of 3.4 nM.
• Linearity was observed over the range of 10-500 nM (R² = 0.9956).
• The method showed comparable sensitivity to existing techniques and outperformed them in greenness (AGREE score: 0.58).

Conclusions:

• The developed DI-SDME-OP method is a sensitive, rapid, and environmentally friendly approach for Rh6G determination.
• The technique integrates multiple analytical steps, simplifying the process.
• The method is suitable for analyzing Rh6G in complex matrices like natural waters and lipstick.