Dear Farha:

Sinigrin is the glucosinolate of horseradish root and black mustard seeds. It is quite polar and water soluble, so an aqueous extraction seems likely. The allyl isothiocyanate is the product of the action of thioglucosidase on the sinigrin substrate. If you want, I could post my book chapter on enzymatically produced benzyl isothiocyanate from a related plant.

TLC will work for the Sinigrin. The isothiocyanate may require gc b/c so volatile.

Best of luck