RESUMEN
Rapid, simple and highly sensitive flow-injection (FI) chemiluminescence (CL) and flow-injection electrogenerated chemiluminescence (ECL) methods were developed for the determination of escitalopram oxalate (ESC), a selective serotonin reuptake inhibitor used as an antidepressant drug. The CL method was based on the CL reaction of ESC with acidic cerium(IV) and tris(2,2'-bipyridyl)ruthenium(II) (Ru(bipy)(3)(2)+). Various experimental parameters affecting CL intensity were carefully studied and optimised. The method enabled the determination of 0.001-50 µg/mL of ESC in bulk form with a correlation coefficient r = 0.9999. The limit of detection (LOD) was 0.01 ng/mL (S/N = 3). The ECL method was based on the ECL reaction of Ru(bipy)(3)(2)+ with the drug in an acidic medium, permitting the determination of ESC in the range of 0.00001-70 µg/mL with r = 0.9999 and LOD of 1 x 10(-4) ng/mL. The proposed methods were applied to the determination of ESC in commercial tablets. The results were compared statistically with those obtained from a published method using t- and F-tests.