Despite many benefits of the most common version of DLLME the choice of the extraction solvent is its main drawbacks. In conventional DLLME, the density of extraction solvent should be higher than that of water.
The high-density extraction solvents, being mostly halogenated, are generally hazardous to laboratory personnel and are not often compatible with reverse phase HPLC. Variousresearch groups have solved this problem in different ways using extraction solvent lighter than water using specialized extraction vessel