The column was washed three times with 1 mL pyridine acetate
(20 mM) and twice with 1 mL water. The glucosinolates were
converted into their desulpho analogues by overnight treatment
with 100 μL of 0.1% (1.4 units) aryl sulphatase (Sigma), and the
desulphoglucosinolates were eluted with 2×0.5 mL water