Determination of atractyloside in Callilepis laureola using solid-phase extraction and liquid chromatography-atmospheric pressure ionisation mass spectrometry

A selective analytical method based on high-performance liquid chromatography, combined with atmospheric pressure ionisation mass spectrometry, was developed for the detection of atractyloside. The analysis was performed on an Xterra Phenyl column utilising a gradient elution profile and a mobile phase consisting of 10 mM aqueous ammonium acetate buffer-methanol-acetonitrile. The calibration curve of the method (1 ng/ml-160 μg/ml) was best described by a second order polynomial function (r² = 0.998) but displayed good linearity in the range of 100 ng/ml-1 μg/ml (r² = 0.999). The limit of detection for the atractyloside standard was determined and found to be 100 pg/ml and the limit of quantification of atractyloside in tuber matrix was found to be 250 pg/ml. The relative standard deviation of the method was on average below 5% (n = 8). The method was successfully applied to the analysis of Callilepis laureola tubers and unknown powdered samples for the presence of atractyloside.