FLOW-INJECTION CHEMILUMINESCENCE DETERMINATION OF THE HYDRAZONES OF AROMATIC KETONES

A flow-injection system for investigating the chemiluminescence of aromatic ketone hydrazones is developed, based on KMnO4 oxidation with formic acid as a carrier. Rhodamine B has proved to be an efficient sensitizer. The hydrazones studied are benzophenone hydrazone, benzil dihydrazone, acetophenone hydrazone and benzoin hydrazone. The relative standard deviation for ten replicate injections of 1 x 10(-5) M benzophenone hydrazone and the detection limit (3 sigma) are 2% and 3 x 10(-6) M (30 pmol, 10-mu l injection), respectively. The interference effect of some metal ions is also investigated. Cu(II), Cd(II), Zn(II), Ca(II), Co(II) and Ni(II) have no effect whilst Mn(II), Mo(VI) and Ce(IV) suppress the signal.