Validation of a reversed phase high performance thin layer chromatographic-densitometric method for secoisolariciresinol diglucoside determination in flaxseed

The validation of a HPTLC-densitometric method for the determination of secoisolariciresinol diglucoside (SDG) in flaxseed was performed improving the reproducibility of a previously reported HPTLC densitometric procedure by the use of fully wettable reversed phase plates (silica gel 60 RP18W F254S, 10 cm × 10 cm) with MeOH:HCOOH 0.1% (40:60, v/v) mobile phase. The analysis required only the alkaline hydrolysis in aqueous medium of undefatted samples and densitometry at 282 nm of HPTLC runs. The method was validated following the protocol proposed by the Société Francaise des Sciences et Techniques Pharmaceutiques (SFSTP) giving rise to a dependable and high throughput procedure well suited to routine application. SDG was quantified in the range of 321–1071 ng with RSD of repeatability and intermediate precision not exceeding 3.61% and accuracy inside the acceptance limits. Flaxseed of five cultivars of different origin was elected as test-bed.