Dispersive liquid-liquid microextraction based binary extraction techniques prior to chromatographic analysis: A review

The recent developments in the analytical sample preparation signpost a trend of combining dispersive liquid-liquid microextraction (DLLME) with other extraction techniques. The objectives of these binary techniques are inclined toward achieving an improvement in separation, cleanup, detection limits, enrichment factors, and coping with complex matrices. DLLME has been combined with both conventional and micro-or miniaturized extraction techniques. It has been either followed by or following another extraction in the combination. This review aims to highlight and share the progress in this area with the analytical community. The objectives and merits of each combination are critically appraised. In the end, a brief description is provided on accomplishments, limitations, and future directions. (c) 2018 Elsevier B.V. All rights reserved.