Dispersive liquid-liquid microextraction is one of the most widely used microextraction techniques currently in the Analytical Chemistry field, mainly due to its simplicity and rapidity. The operational mode of this approach has been constantly changing since its introduction, adapting to new trends and applications.Most of these changes are related to the nature of the solvent employed for the microextraction. From the classical halogenated solvents (e.g., chloroform or dichloromethane), different alternatives have been proposed in order to obtain safer and non-pollutants microextraction applications. In this sense, low density solvents, such as alkanols, switchable hydrophobicity solvents and ionic liquids were the first and most popular replacements for halogenated solvents, which provided similar or better results than these classical dispersive liquid-liquid microextraction solvents.However, despite the good performances obtained with low density solvents and

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Miniaturization of the analytical process has been a widespread trend, and the sample preparation stage is not exempted from this downscaling. Since the introduction of microextraction techniques as miniaturization of classical extraction techniques, they have become one of the strengths in this field. However, some of the original approaches to these techniques did not fully cover all the current principles of Green Analytical Chemistry. For this reason, during the last years, much emphasis has been placed on reducing/eliminating toxic reagents, reducing the amount of the extraction phase, and searching for new greener, and more selective extractant materials. On the other hand, even though high accomplishments have been achieved, the same attention has not always been paid to reducing the amount of sample, which is essential when treating low‐availability samples such as biological samples, or in developing portable devices. In this review, we intend to give the readership an overview of the advances toward further miniaturization of microextraction techniques. Finally, a brief reflection is made on the terminology used, or that should, in our opinion, be used to term these new generation of miniaturized microextraction approaches. To this regard, the term, ‘ultramicroextraction’ is proposed to refer to those approaches beyond microextraction.

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Vitamin A (retinol) and some of its derivatives are a group of fat-soluble compounds used in cosmetic products as bioactive ingredients. Therefore, it is necessary to perform the quality control of final product to ensure their efficacy and safety. A simple and rapid method to determine retinol, retinal, retinyl acetate, retinyl propionate and retinyl palmitate in cosmetics is presented here. The method is based on vortex and/or ultrasound-assisted leaching of the analytes in ethanol followed by liquid chromatography with ultraviolet detection. The analytical performance of the method was evaluated. It has shown high levels of linearity, at least up to 100 µg mL−1; high precision with RSD values below 14% and high sensitivity with low MLODs ranging between 0.3 × 10−4 and 5.9 × 10−4 % w/w, which are enough to monitor these compounds in cosmetic products. The proposed method was successfully applied to seven commercial cosmetic samples to detect and quantify the target analytes, showing the method is suitable for its employment for quality control in cosmetic industries. Cosmetic samples were spiked at two levels of concentration and recovery values around 100% were obtained, showing no significant matrix effects and, therefore, external calibration was adequate for this determination.