Determination of triclosan by cuvetteless UV-vis micro-spectrophotometry following simultaneous ultrasound assisted emulsification-microextraction with derivatization: Use of a micellar-ionic liquid as extractant

Two ultrasound-assisted emulsification-microextraction procedures based on the use of a micellar ionic liquid as extractant are proposed for triclosan determination in troublesome matrices such as cosmetics and wastewaters. Microvolume UV-vis spectrophotometry was used in order to quantify the yellow azoderivative formed. This compound is polar and water-soluble and hence, it is not extractable into conventional organic solvents. Two imidazolium based ionic liquids were used as extractants. An improvement in the extraction of the derivative was achieved when SDS was mixed with the ionic liquid. The use of ultrasound energy allows a fast emulsification of the system. All the parameters related to the emulsification-microextraction were carefully optimized (i.e., ionic liquid type and volume, SDS concentration, sonication time and amplitude, salt addition, disperser solvent, cooling of ionic liquid and centrifugation time). Matrix effects were assessed and external calibration was used in all cases. Several advantages such as high sample throughput, simplicity and low reagent consumption can be emphasized. (C) 2011 Elsevier B.V. All rights reserved.