Chemiluminometric determination of carvedilol in a multi-pumping flow system

In this work a simple, fast, sensitive and selective flow-based procedure for the chemiluminometric determination of carvedilol, a recent non-cardioselective beta-blocker with noteworthy antioxidant activity, is proposed. The developed methodology takes advantage of the antioxidant capacity of carvedilol to inhibit the chemiluminescence response resulting from the oxidation of luminol by hypochlorite, by acting as a hypochlorite scavenger. The analytical process was implemented in a multi-pumping flow system that employs multiple solenoid actuated micro-pumps as the only active components. These acted as solution insertion, propelling and commuting units assuring an easily controlled, low cost, compact and reliable analytical system. A linear working range for carvedilol concentrations ranging from 1.2x10(-7) to 3.0x10(-6)moll(-1) (r>0.999, n=6), was obtained, with a detection limit of 8.7x10(-9)moll(-1). The system handles about 65 samples per hour yielding precise results (R.S.D.<1.3%, n=10). Recoveries within 95 and 104% were obtained.