Chemiluminescence determination of N-tetrahydrobenzothiazolyl imine Schiffbase

Five newly synthesized N-tetrahydrobenzothiazolyl imines show weak chemilum inescence (CL) when oxidized by Ce(N) in sulfuric acid, which is significan tly enhanced when quinine is present as sensitizer. The possible mechanism is proposed based on CL spectrum, fluorescent spectrum and absorbent spectr um of Schiff base. The relationship between the CL intensity and the concen tration of Schiff base is linear in the range of 2. 0X10(-7)-8.0X10(-5) mol /L, and the detection limit is 8.0X10(-8) mol/L. The relative standard devi ation(RSD) for 7 independent determinations of 2. 0X10(-6) mol/L Schiff bas e is 2. 4%. Common excipient starch was used in pharmaceutical preparation and most of metal ions do not interfere with the determination of Schiff ba se, except Mn( II), Fe(III), Fe(II), Bi(III), Ti(I). The method has been su ccessfully used in analysis of synthesized samples.