The determination of vitamin K-3 using the coupling between a photochemical
reaction and a chemiluminescent reaction in a flow system is described. Th
e method is based on the photooxidation of ethanol sensitized by vitamin K-
3 to yield hydrogen peroxide, which is monitored through the chemiluminesce
nt reaction with luminol catalysed by hematin. The new approach allows the
determination of vitamin K-3 in a wide concentration range (1 x 10(-7)-5 x
10(-4) mol l(-1)) with a throughput of 30 samples h(-1). The applicability
of the method was demonstrated by the determination of vitamin K-3 in pharm
aceutical preparations.