Dispersive liquid-liquid extraction

DISPERSIVE LIQUID-LIQUID

MICROEXTRACTION

Dispersive liquid–liquid microextraction (DLLME) was designed as a high performance and powerful preconcentration method which is based on ternary component solvent system such as homogeneous liquid–liquid extraction and cloud-point extraction (Rezaee M et al., J Chromatogr A 2006, 1116, 1).
In this method, the appropriate mixture of extraction solvent and disperser solvent is injected into aqueous sample by syringe, rapidly. Thereby, cloudy solution is formed. The advantages of DLLME method are simplicity of operation, rapidity, low cost, high recovery, and enrichment factor.

In this method, the appropriate mixture of extraction solvent (8 μL C₂Cl₄) and disperser solvent (1 mL acetone) are injected by syringe into the aqueous sample (5 mL) containing substituted benzene compounds, rapidly. Therefore, cloudy solution is formed. In fact, it is consisted of fine particles of extraction solvent which is dispersed entirely into aqueous phase. After centrifuging, the fine particles of extraction solvent are sedimented in the bottom of the conical test tube (5.0 ± 0.2 μl).
The performance of DLLME was illustrated with the determination of polycyclic aromatic hydrocarbons (PAHs), other organic compounds such as organochlorine pesticides, organophosphorus pesticides, fatty acids, and cholesterol. 
The advantages of DLLME method are simplicity of operation, rapidity (some seconds), low cost, high recovery, and enrichment factor.
A review focused on the updated developments and applications of DLLME. It covers almost all the publications related to the procedure from the beginning. In addition, some limitations and an outlook on further developments are discussed (Rezaee M et al., J Chromatogr A 2010, 1217, 2342).

A broad range of polar or ionizable organic compounds present in various matrices such as urine, blood, plasma were derivatized and extracted according to the DLLME techniques (Nuhu AA et al., J Chromatogr B, 2011, 879, 1180).

The automation of the DLLME process has been described using the original concept and enabling the direct injection of the separated extractant into a hyphenated analytical instrumentation (Cerda V et al., Molecules 2022, 27, 7279).

Dispersive liquid-liquid microextraction was used for fat-soluble vitamin determination in serum by LC-MS/MS (Li J et al., Biomed Chromatogr 2023, 37, e5666) and for long-chain fatty acids found in lipid-rich wastewaters (Vargas-Muñoz MA et al., Anal Bioanal Chem 2021, 413, 3833).

DLLME parameters, including the type and volume of extractant and dispersant, pH, and ionic strength were optimized to improve extraction performance of fatty acids in oysters tissues (Zaid A et al., Food Chem 2025, 492(Pt 1), 145307).