Enhancing Analytical Sensitivity and Selectivity for Methylene Blue Determination in Water Samples by Using...

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Environmental Science

Background:

• Optical absorption spectroscopy lacks sensitivity for low analyte concentrations.
• Surface-enhanced Raman spectroscopy (SERS) offers high sensitivity but low selectivity in complex matrices.
• Analyzing trace contaminants in water requires sensitive and selective methods.

Purpose of the Study:

• To integrate multiphase electroextraction (MPEE) with optical absorption spectroscopy and SERS.
• To determine methylene blue (MB) dye in tap water samples.
• To overcome the limitations of individual spectroscopic techniques for trace analysis.

Main Methods:

• Sample preparation using multiphase electroextraction (MPEE).
• Optimization of MPEE parameters (extraction time, pH, acetonitrile percentage) using Box-Behnken design.
• Analysis of methylene blue (MB) using optical absorption spectroscopy and SERS.

Main Results:

• Optical absorption spectroscopy achieved a linear range of 30-375 mg L^-1 MB with high precision and recovery.
• SERS enabled detection of MB at concentrations as low as 0.05 μg L^-1.
• MPEE improved detection limits to ppb and ppt levels for MB in water samples.

Conclusions:

• MPEE effectively enhances the sensitivity and applicability of spectroscopic techniques for analyzing trace contaminants.
• The integrated MPEE-spectroscopy approach is suitable for routine analysis of challenging water samples.
• This method offers a viable solution for sensitive detection of pollutants like methylene blue.