Chemiluminescence determination of tetracyclines using Fenton system in the presence europium(III) ions

A new simple chemiluminescent method for the determination of chlortetracycline (Chlor-TC), oxytetracycline (Oxy-TC) and doxycycline (Doxy-TC) is described. This method is based on the europium(III) emission as a result of the energy transfer process from the excited product of the tetracyclines oxidation to the uncomplexed Eu(III). Under the optimum conditions, calibration graphs were obtained for 4 × 10−7 to 2 × 10−5 mol L−1 of Chlor-TC; 2 × 10−7 to 2 × 10−5 mol L−1 of Oxy-TC and 1 × 10−7 to 3 × 10−5 mol L−1 of Doxy-TC. The method was successfully applied to the determination of these drugs in pharmaceutical and veterinary formulation and honey.