Innovative Solutions for the Extraction of Vitamins from Pharmaceutical and Biological Samples

Background: The extraction of vitamins from complex matrices, such as pharmaceutical and biological samples, is a demanding task. Progress in material science is revolutionizing sample preparation, leading to the development of more efficient, sensitive, and selective analytical methods. In particular, the evolution of solid-phase extraction towards miniaturized techniques is closely related to the introduction of nanomaterials as new sorbents. Microextraction techniques, both solid-based and liquid-based, allow for the reduction of solvent and sample volumes, as well as the sample processing times. In many cases, these procedures are also environmentally friendly. Moreover, the substitution of traditional organic solvents with the neoteric ones is another current trend in analytical chemistry. Aims: The aim of this review is to introduce readers to the innovative solutions available for the extraction of vitamins from matrices of different complexity. Methods: Research papers in the literature of the last five years are reviewed, providing a critical description of the most original and interesting sample preparation approaches devoted to vitamin extraction. Results: Among the last five years of literature concerning the analysis of vitamins in the clinical and pharmaceutical sectors, only 40% of works applied some innovative or green approaches to sample preparation. However, a general trend is the reduction of solvent volumes and sample processing times. Conclusion: The great potential of microextraction techniques based on nanomaterials and neoteric solvents has not been fully exploited yet in the clinical and pharmaceutical fields. Considering the high cost of carbon-based nanomaterials, it can be expected that in the near future, liquid microextraction techniques based on neoteric solvents will be more effective for sample preparation. Thanks to their low cost, environmental compatibility, simplicity, speediness and high enrichment factor, these extractive techniques are particularly significant for vitamin analysis.