ROOM-TEMPERATURE PHOSPHORESCENCE OPTOSENSOR FOR TETRACYCLINES

A flow-through optosensor for tetracyclines based on the tetracycline-europium chelate room temperature phosphorescence energy transfer is proposed. The sensor is developed in conjunction with a flow-injection analysis system and is based on the transient immobilization on a non-ionic resin (packed in a flow-through cell) of the tetracycline-europium chelate. The analytical performance characteristics of the proposed sensor for semiautomated analysis and control of very low levels of tetracycline were as follows: the detection limits for tetracycline, oxytetracycline and chlortetracycline were 0.25, 0.30 and 0.40 ng ml-1, respectively, with a relative standard deviation of 1% for determination of 0.24 mug ml-1 of each antibiotic (n = 10). Most of the common metal ions in biological samples did not interfere, except Fe(III) which caused serious interference and should be masked with 1,10-phenanthroline. The recommended method has been successfully tested for determination of tetracyclines in clinical samples (urine and pharmaceutical preparations).