Automated temperature-responsive deep eutectic solvent microextraction for rapid determination of synthetic dyes in...

Area of Science:

• Analytical Chemistry
• Food Science
• Environmental Science

Background:

• Synthetic dyes are widely used in food products, but some are banned due to health concerns.
• Accurate and efficient methods are needed for detecting these banned synthetic dyes in complex food matrices.
• Traditional methods often involve toxic organic solvents and extensive sample preparation.

Purpose of the Study:

• To develop an automated microextraction method for determining banned synthetic dyes in food samples.
• To utilize temperature-responsive deep eutectic solvents (TRDESs) for efficient and environmentally friendly extraction.
• To validate the method's performance and assess its green credentials.

Main Methods:

• Development of an automated flow-based platform using a homogeneous aqueous TRDES solution (lidocaine and heptanoic acid).
• Thermally induced phase separation of the TRDES for direct extract collection without centrifugation.
• Optimization and validation for Rhodamine 6G, Sudan I, II, and III in food samples, including molecular dynamics simulations.

Main Results:

• Achieved good linearity (0.025-100 mg L⁻¹) and low limits of detection (0.001-0.008 mg L⁻¹).
• Demonstrated high precision (RSDs: 2-7%) and successful analysis of real beverage samples with good spiked recoveries (1-5% bias).
• Confirmed extraction mechanism via molecular dynamics and high environmental sustainability via AGREEprep and ComplexGAPI.

Conclusions:

• The proposed automated TRDES microextraction method is robust, efficient, and environmentally friendly for detecting banned synthetic dyes.
• The system offers a sustainable alternative to conventional methods, avoiding toxic solvents and complex procedures.
• This technology provides a valuable tool for trace-level screening of synthetic dyes in food matrices, enhancing food safety.