Extracting solvent Process Efficiency (%) Ethyl acetate 65.4 Di ethyl ether 48.6 Tertiary butyl methyl ether 41.3 Preparation of sample:500 μL of 1% formic acid in water solution as pretreatment for 100 μL of plasma.

Table 2: Optimization of extracting solvent for liquid-liquid extraction based on process efficiency at LQC level analyzed on model API-3000.