Office chromatography (OC) aims to boost the performance of ultrathin-layer chromatography (UTLC). What obstacles were you
aiming to overcome with this technique?
Firstly, miniaturized plate formats are very difficult to handle and manage with the thin-layer chromatography (TLC) and high-performance
thin-layer chromatography (HPTLC) equipment currently available. This lack in instrumentation combined with the reduced surface
activity of monolithic UTLC layers has hampered its progress for almost a decade. It is also not easy to find out how to use
UTLC plates correctly. For example, when analysts transfer a particular HPTLC method to UTLC they get different chromatographic
results. But for a successful transfer, the elution strength of the mobile phase has to be reduced significantly and nanolitre
volumes of a more concentrated solution need to be applied to generate real sharp start zones, which is crucial.
Planar chromatography is the only chromatographic method that can synergetically benefit from print and media technologies
because of its open planar format of the stationary phase. Office chromatography (OC), which aims to combine print and media
technologies with chromatography, will lead to the development of instrumentation that will visibly improve the results that
can be achieved on such small plates. The print of sharp start zones offers a good start for OC. Secondly, for UTLC plates
particularly, the continuous print of the mobile phase is possible because the highly reduced layer thickness scales the relevant
supply volume down; separations can be performed in 1 min2,3 with mobile phase consumption only in the microlitre range. Different types of UTLC plates have been reported to accelerate
the chromatographic separation.4–8 Finally, this minor mobile phase volume can be evaporated by infrared (IR) bulb scans of a flatbed scanner positioned beneath
the plate. Electronic documentation of the dry plate by different light bulbs, which also fit in the flatbed scanner, allows
a high-resolution image of the small-scale plate dimension. All in all, OC will offer the first real chance for a one-click
planar chromatographic system because all steps (application, development and evaluation) are integrated in one system. Of
course, such a system will lower the degree of flexibility, but an online system would be convenient to many analysts because
it increases the free time available for the analyst compared with TLC or HPTLC. OC is online and the whole proces can be
started with one click.
PLANAR CHROMATOGRAPHY DEFINITIONS