A simple, sensitive, and rapid kinetic-fluorimetric method based on the oxi
dation of ethylenethionrea with cerium (IV) is proposed for the determinati
on of ethylenethiourea. The rate of formation of fluorescent cerium (III) i
s high, while the stopped flow mixing technique allows this initial rate to
be easily measured and facilitates the automation of the method. The calib
ration graph is linear over the range 0.1-2 mug mL(-1) and the precision (%
RSD) is close to 1.1%. The usefulness of the method was tested for the det
ermination of ethylenethiourea in water, milk, and fruit.