was a much better eluent than the other solvents
for all herbicides; elution varied between 25 and
60% with n-hexane and acetonitrile, respectively.
The influence of the eluent (ethyl acetate) volume
was examined by changing the loop of IV2 (Fig.
1), the optimum volume being 100 l; a second
elution using the same volume showed the absence
of carry over.