Recent efforts to increase greenness in chromatography

Conventional high-performance liquid chromatography (HPLC) and gas chromatography (GC) are the most widely used analytical tools in the analytical chemistry field. However, these successful techniques present a number of unfriendly environmental issues. Thus, conventional HPLC needs large amounts of organic solvents and generates high amounts of wastes, conventional GC mostly uses non-renewable and expensive gases such as He (particularly when combined with mass spectrometry), and conventional HPLC and GC are both time- and high energy-demanding. This review describes recent modifications (2018–2020) introduced in HPLC and GC techniques to improve their greenness, covering topics such as mobile phases and mobile phase additives, novel stationary phases, and mostly the miniaturization of the equipment with the purpose of simplification and costs reduction.