Novel deep eutectic solvent-based liquid phase microextraction for the extraction of estrogenic compounds from...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Green Chemistry

Background:

• Steroid hormones like estrone (E1), 17β-estradiol (E2), 17β-ethinylestradiol (EE2), and estriol (E3) are lipophilic compounds with significant biological activity.
• Accurate determination of these estrogenic compounds in environmental water and wastewater is crucial for ecological and human health risk assessment.
• Traditional extraction methods can be time-consuming, solvent-intensive, and may lack efficiency for trace-level analysis.

Purpose of the Study:

• To develop and validate a pH-switchable hydrophobic deep eutectic solvent-based liquid phase microextraction (DES-LPME) technique.
• To determine estrogenic compounds (E1, E2, EE2, E3) in environmental water and wastewater samples.
• To establish a green, efficient, and sensitive analytical method using gas chromatography-mass spectroscopy (GC-MS).

Main Methods:

• A deep eutectic solvent (DES) was synthesized using l-menthol (HBA) and (1S)-(+)-camphor-10-sulfonic acid (CSA) (HBD) as a green extraction solvent.
• The pH-switchable nature of the DES was utilized for phase transition and analyte extraction without centrifugation.
• Optimization of effective parameters including DES composition, volume, pH adjustment (KOH, HCl), salt addition, and extraction/derivatization times was performed.

Main Results:

• The optimized DES-LPME method coupled with GC-MS demonstrated excellent linearity (0.5-100 ng L⁻¹) and low limits of detection (0.2-1.0 ng L⁻¹).
• Intra-day and inter-day relative standard deviations (RSD) were within acceptable ranges (2.2–4.6% and 3.9–5.7%, respectively).
• High relative recoveries (91.0–108.8%) were achieved for spiked environmental water and wastewater samples, indicating method robustness.

Conclusions:

• The developed pH-switchable DES-LPME technique is a highly effective and green approach for the sensitive determination of estrogenic compounds.
• This method offers advantages such as rapid extraction, simple phase separation, and reduced solvent consumption.
• The technique shows great potential for routine environmental monitoring of endocrine-disrupting compounds in complex matrices.