Table 3.

Comparison of recovery yields in several extraction methods for isolating ethyl carbamate

Method	I	II	III	IV	V	VI	VII	VIII	IX (ATPS)
Treatment	EC+BC	EC+BC	EC+BC	EC+BC	EC+BC+NaCl	EC+BC+NaCl	EC+BC+NaCl	EC+BC+NaCl	EC+BC+K2HPO4
Solvent	DCM	DCM	CF	CF	DCM	DCM	CF	CF	‒
Mixing	Vortex	Ultrasonic	Vortex	Ultrasonic	Vortex	Ultrasonic	Vortex	Ultrasonic	Vortex
Yield	43±5	42±3	47±4	43±3	53±8	57±2	62±11	58±6	90±4

Values are presented as mean±standard deviation for triplicate.

Both concentrations of NaCl and K₂HPO₄ are 15%. A vortex is used for 10 s and ultrasonic is operated for 30 min in a bath.

ATPS, aqueous two-phase system; EC, ethyl carbamate; BC, butyl carbamate; DCM, dichloromethane; CF, chloroform.