Determination of enalapril maleate andatenolol in their pharmaceutical productsand in biological fluids by flow-injectionchemiluminescence.

Abstract

A chemiluminescent method using flow injection (Fl) was investigated for rapid and sensitive determination ofenalapril maleate and atenolol, which are used in the treatment of hypertension. The method is based on the sensitizing effectof these drugs on the Ce(lV)-sulfite reaction.Thedifferent experimental parameters affecting the chemiluminescence (CL) intensitywere carefully studied and incorporated into the procedure. The method permitted the determination of 0.01-3.0 µg Ll-1 ofenalapril maleate in bulk form with correlation coefficient r= 0.99993, lower limit of detection (LOD) 0.0025µg mL-1 (S/N = 2) and lower limit of quantitation (LOQ) of 0.01µg mL-1. The linearity range of atenolol in bulk form was 0.01-2.0 µg mL-1 (r=0.99989) with LOD of 0.0003 µg mL-1 (S/N = 2) and LOQ of 0.01µg mL-1 .ln biological fluids the linearity range of enatapril maleatewas 0.1-2.0 µg mL-1in both urine and serum, and for atenolol the linearity range was 0.1-1.0 µg mL-1in both urine andserum.The method was also applied to the determination of the drugs in their pharmaceutical preparations.