Simple densitometric method for estimation of cyanogenic glycosides and cyanohydrins under field conditions

In this new design of the picrate test (Guignard Method) for small scale cyanide determination under field conditions, hydrolysis of the cyanogenic compounds is catalysed by ‘β-glucuronidase’, a commercial enzyme preparation from Helix pomatia. The method described facilitates the quantification of small amounts of cyanogenic compounds in plant material, with a detection limit about 60 ng of released HCN (equivalent to 1μg of amygdalin). False positive tests produced by hydrolysis products of glucosinolates could be excluded by inhibition of the myrosinae enzyme system present in plants that contain glucosinolates. The total weight of equipment needed for a total of 1000 determinations (in groups of eight) does not exceed 500 g, thus making the method convenient for field work.