- Biomedical Research (2007) Volume 18, Issue 2
Detection of quinolones on thin layer chromatographic plates using sigma- and pi-acceptors in 1,4-dioxane
The use of sigma- and pi-acceptors for the detection of some quinolones on thin layer chromatographic plates was investigated. Thin layer chromatographic plates, coated with silica gel were air dried and stored in an oven at 110oC for 30 minutes. Before use, the plates were allowed to cool to room temperature. Each of the drug samples (Reference, Cipro®, Ofloxacin) was spotted twice on a pair of coated plates. The plates were then placed vertically in a development tank containing a solvent system and allowed to stand undisturbed until the solvent front reached 15cm from the origin. The plates were then removed, air dried and sprayed with an appropriate locating reagent (iodine or chloranilic acid) and examined for colour formation/stability. In another set of experiments, the plates were counter sprayed with dimethyl formamide (DMF) and re-examined for reaction. The results showed that the chromogens formed from iodine and chloranilic acid were reddish brown and violet respectively. The reddish brown colour changed to yellow meanwhile the violet colour disappeared after six and 20 minutes, respectively. On counter spraying with DMF, the reddish brown colour changed to yellow and there was no increase in intensity in the reference drug, but there was in the test drugs. However, the intensity of the violet colour was generally increased. There were no significant differences (P>0.05 for each) in the Rf values of iodine and chloranilic acid chromogens of all the drugs. Sigma- and pi-acceptors can be applied in qualitative detection of quinolones
Author(s): E. N. Shu, K. N. Muko, S. O. Ogbodo, I. C. Maduka, M. N. Ezeunala