Neglected Applications of Monolithic Structures: The Beginnings of Planar Chromatography with Mass Spectrometric Detection

Thin layer chromatography (TLC) has been first reported by N. A. Izmailov and M. S. Schreiber in the late 1930s. The liquid mobile phase usually moves pores of a supported rigid plate placed vertically simple container, e.g., beaker. flow is driven capillary forces only no sophisticated instrumentation required. individual components mixture are separated based on differences their affinity for solid stationary phases. typical format represents thin coated glass, aluminium, or plastic plate. porous sorbents can be silicon dioxide (silica), aluminium oxide (alumina), cellulose, held together, with gypsum. main advantages TLC ease carrying out separations, which also take place parallel lines same plate, equipment, single use, static detection, possibility archiving separation result dried layer. However, 100–250 μm thick layers not well suited combination mass spectrometry (MS). This led to commercialization ultrathin 10 monolithic silica layers. Unfortunately, production was soon discontinued. Alternative solutions that problem originated from academic environment. In one approach, were formed nanofibers prepared electrospinning. Alternatively, polymers produced polymerization situ variety separations both small large molecules demonstrated. use MS detection then enabled determination molecular compounds spots. Although preparation originally appeared straightforward, some unexpected problems had solved. review details issues related history presents approaches leading behaving suitable desired separations.