Analytical Sciences

Abstract − Analytical Sciences, 17(11), 1257 (2001).

Flow-injection Chemiluminometric Determination of Some Thioxanthene Derivatives in Pharmaceutical Formulations and Biological Fluids Using the [Ru(dipy)32+]-Ce(IV) System
Fatma A. ALY,* Salma A. AL-TAMIMI,* and Abdulrahman A. ALWARTHAN** 
*Chemistry Department, College of Science, King Saud University (Girls), P. O. Box 22452, Riyadh 11495, Saudi Arabia
**Chemistry Department, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia
A flow-injection (FI) methodology using tris(2,2'-dipyridyl)ruthenium(II), [Ru(dipy)32+], chemiluminescence (CL) was developed for the rapid and sensitive determination of three thioxanthene derivatives, namely zuclopenthixol hydrochloride, flupentixol hydrochloride and thiothixene. The method is based on the CL reaction of the studied thioxanthenes with [Ru(dipy)32+] and Ce(IV) in a sulfuric acid medium. Under the optimum conditions, calibration graphs were obtained over the concentration ranges 0.002 - 6 ug/ml for zuclopenthixol hydrochloride, 0.5 - 15 ug/ml for flupentixol hydrochloride and 0.05 - 7.5 ug/ml for thiothixene. The limits of detection (s/n = 3) were 4.2 x10-9 mol/l zuclopenthixol hydrochloride, 2 x 10-8 mol/l flupentixol hydrochloride and 4.5 x 10-8 mol/l thiothixene. The method was successfully applied to the determination of these compounds in dosage forms and biological fluids.