Miniaturized planar chromatography using office peripherals — Office chromatography

• Combination of miniaturized planar separation science and print & media technologies.
• Site-specific printing as lines or areas on defined sections of the layer.
• Image-giving miniaturized chromatograms.
• Appropriate analytical technique for green chemistry.
• Online planar chromatography.

Office chromatography (OC) harnesses the novel combination of miniaturized planar separation science and modern print & media technologies. Interdisciplinary knowledge is the essence: Printing of solutions on powerful miniaturized planar separation materials in combination with image capturing and evaluation tools enables an innovative analytical online system. Site-specific printing as lines or areas on defined sections of the layer comprises important steps like application of samples, feeding of the mobile phase as well as supply of the derivatization reagent. Also printing of bioassays can be combined for effect-directed detections and the homogeneous printing of the ultrathin layer itself, enabling tailor-made gradient-layer or multi-layer plates. OC exploits image-giving miniaturized chromatograms being captured and processed with a flatbed scanner or mini-camera. Thus, miniaturized separation materials are the core of OC. Monolithic, electrospun, nanostructured glancing angle deposition and carbon nanotube-templated microfabricated layers or even pillar arrays or polymer brush coated sub-μm silica particles were demonstrated, showing promising results. Layer thicknesses from 50 μm down to few micrometers were explored. A high-throughput capacity is given through the parallel development of as many as possible tiny-printed samples on the separation material. The migration time was reduced to a few minutes and the calculated analysis time per sample lasted few seconds. Considering a substantially reduced solvent consumption at short run times for parallel analysis of numerous samples at the same time, OC is an appropriate analytical technique for green chemistry. OC facilitates the whole planar separation process to be performed with no other equipment but a combined device of printer and flatbed scanner or mini-camera. At the same time, OC can be expected to become a widespread and economical technique with the user-friendliness of high-end office tools, appealing to users.