Extractive silylation method for high throughput GC analysis of flaxseed cyanogenic glycosides

The reported methods for the estimation of CG are indirect, long and tedious uses solvent extraction which results in lower recoveries due to several co-eluted components. The present study aims to develop and validate a high throughput method for the analysis of cyanogenic glycosides (CG) in flaxseed using extractive silylation. The experimental procedure comprised of preparation of trimethylsilyl (TMS) derivatives of CG, their quantitation through gas chromatography with flame ionization detector (GC-FID) and further characterization by LC-MS/MS. Different validation parameters determined in the experiment include the relative standard deviation both inter-day and intraday less than 5%, recovery in the range of 79.9-112.7%, limit of detection 4.72-6.43 µg/mL and limit of quantitation 14.31-19.50 µg/mL. Combinations of silylation reagent were screened in a central composite experimental design in order to examine their effect on the extraction recovery. Finally, the developed method was applied successfully to quantify CG in various flaxseed cultivars. Advantages of the extractive silylation are simple preparation, short reaction times and the combination of extraction and silylation in one step which indicate that the method has the potential to sensitively and accurately determine CG where large numbers of samples are being routinely analysed.