Whatman 541 filter paper devices

Homogenizer with high-speed rotary blades Vacuum filtration device Whatman no. I filter paper Separatory funnel... 

In paper chromatography we use filter paper, marketed for this purpose. It comes usually in the form of a 2-5 cm-wide tape, from which a strip of the necessary length can easily be cut. The more modern technique of thin layer chromatography (TLC), makes use of thin sheets of aluminium oxide, silica-gel, cellulose or some other material, supported by a metal sheet or a polymer. Chromatographic thin layers can be prepared in the laboratory from commercially available adsorbents. A thick suspension of these is made with water (usually a 2 1 w/w mixture of water adsorbent is made up) and this is then spread on a metal plate with a suitable spreader device. Techniques vary from device to device, and the instructions of the manufacturer should be followed whenever thin layer plates are to be prepared. Ready-made thin layer sheets are also available commercially. These contain the active material spread on a plastic support. Thin-layer chromatographic materials, especially ready-made plates, are much more expensive than chromatographic paper, but normally offer faster and sharper separations than the paper. The procedures described in Section VI.20 can be carried out both on a slow chromatographic paper (e.g. Whatman No. 1) or on a cellulose thin layer (e.g. Whatman cellulose). 

There are a variety of paper materials available to the user, although the choice is based mainly on the fabrication steps required in developing a device and also on the specific application area. In the development of sensors and microfiuidic technologies, filter paper has seen widespread use in recent years for producing paper-based sensors due to its wicking ability (Li et al. 2010 Martinez et al. 2010). In particular, the Whatman cellulose range is popular with the important parameters of porosity, particle retention, and flow rate differentiating the filter paper types. 

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