New sorbents for sample pretreatment: Development and applications

Abstract

Sample preparation prior to instrumental analysis is a key step to achieve high quality qualitative/quantitative analytes determinations present in complex samples. Development of pretreatment methods, with the aim of preconcentrate analyte(s) of interest or isolating them from their matrices which may contain possible interferents, has been a continuous task over the years. Multiple goals are pursued to obtain improved pretreatment methods, such as low sample consumption, specificity or selectivity, high throughput, simplicity, robustness, as well as reducing economic costs. In recent years, sample pretreatment has also focused on reducing environmental pollution and enabling miniaturization and automation. Therefore, classic methods of liquid-liquid extraction and liquid-solid extraction are being replaced at a significant rate by miniaturized techniques such as single-drop microextraction, dispersive liquid-liquid microextraction, solid-phase microextraction, dispersive solid phase microextraction, microextraction with packed sorbents, among others, using a wide variety of sorbents, including monolithic polymers, metal-organic frameworks, carbon-based and magnetic nanomaterials. This review summarizes the most relevant progress achieved in the last five years on advanced sorbent materials for sample preparation. In addition, most employed miniaturized solid phase extraction techniques and their applications to extraction of organic compounds in complex matrices were considered. Advantages and disadvantages, analytical performance, as well as their underlying principles and environmental benefits are discussed. Several applications of these modern materials in sample preparation methods are shown and future trends in the development of new sorbents used are proposed.