A HPTLC densitometric determination of umckalin in Pelargonium sidoides and its extracts

Umckalin content in Pelargonium sidoides and its extracts have been compared. Umckalin was separated on a thin-layer of silica gel with two-step gradient elution and determined by HPTLC-photodensitometry. The separation was carried out on a TLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The proposed method is simple and sensitive and can be used for routine assay of umckalin in phytomedicines containing Pelargonium extracts. Umckalin curve is linear (r >0.99) over a concentration range of 0.16–0.80µg/spot. Recovery from capsules and tinctures is statistically equal to 100%. The precision of the method with respect to time and concentration is acceptable, with relative standard deviation (RSD) values of 1.28 and 1.49%, respectively.