Sample preparation for environmental monitoring under the perspective of white analytical chemistry: Green, sustainable and, effective

Abstract

White analytical chemistry (WAC) emerges as an integrative concept that expands the traditional paradigm of green analytical chemistry by incorporating analytical performance (red), environmental sustainability (green), and practical/economic feasibility (blue). This review critically examines the main sample preparation techniques through the lens of WAC, highlighting their alignment with sustainability and analytical excellence in environmental applications. Conventional and emerging methodologies, including liquid-liquid extraction (LLE), solid-phase extraction (SPE), supercritical fluid extraction (SFE), and miniaturized techniques are discussed along with novel materials such as metal-organic frameworks (MOFs), carbon-based sorbents, and green solvents like ionic liquids and deep eutectics. Through this approach, the review highlights the potential of WAC to guide the development of sample preparation workflows that are not only efficient and reproducible, but also safer, cleaner, and more affordable for real-world environmental monitoring. Several application involving water, food and waste samples are reported, demonstrating how WAC-driven strategies achieve high “whiteness” scores, reinforcing their practical relevance and ecological value.