Determination of the lignan secoisolariciresinol diglucoside from flaxseed (Linum usitatissimum L.) by HPLC

A high performance liquid chromatographic (HPLC) technique coupled with photodiode array (PDA) detection was developed for determining secoisolariciresinol diglucoside (SDG) in extracts of flaxseed from different locations in Gansu province, China. The optimized method was achieved for the separation and detection of selected constituents using acetonitrile-1% aqueous acetic acid (15:85, v/v) as the mobile phase at a flow rate of 1.0 mL/min, and 280 nm as the detection wavelength. SDG showed good linearity in a relatively wide concentration range (r = 0.9999). Intra- and inter-assay accuracy and precision were all lower than 5.0%. Sample extracting and hydrolyzing procedures were intensively explored, treating of extraction methodology, solvent, time, and hydrolysis temperature, and alkali concentration. The recovery of the method was 95.3% with a relative standard deviation (RSD) of 0.67%. Different samples of flaxseed varied considerably in the content of SDG.