Characteristics of paper:
Problem:
Explain the characteristics of paper used in PC.
Could van Deemter equation be applied to TLC?
Same to iodine used for detection in TLC, can one use Br2 for the detection of organic compounds.
Explain how Rf value is different from retention time, tr. How do you justify the use of retention time in TLC?
Answer:
In case of PC, paper acting, as stationary phase is difficult to get in reproducible form. Further, it is difficult to get it in humid free form. Also, there is no universal detector in PC unlike in TLC where some common detectors like iodine and ninhydrin can be used. Further, PC takes longer time for analysis compared to that for TLC. Just for these purpose extremely few attempts have been made along with regard to automation in PC.
Also, in case of PC, the particle size cannot be controlled whereas it is an essential condition in the conversion to high-performance form.