FLOW-THROUGH PHOTOMETRIC SENSOR FOR DETERMINATION OF SULFONAMIDES

A sensor based on integration of spectrophotometric detection and rete ntion of the product of the Bratton-Marshall reaction for the determin ation of sulfanilamide, sulfamethazine, sulphaquinoxaline and sulfathi azole is reported. The methods developed using this sensor in a flow i njection manifold feature linear ranges for these analytes between 10 and 1200 ng ml(-1) with relative standard deviations smaller than 2.6% in all instances and they were applied to the determination of sulfon amides in spiked milk and water samples with excellent results. The tw o main advantages of these sensor-based methods over other automated a nd non-automated counterparts are enhanced sensitivity as a result of in situ concentration and avoidance of using a de-bubbler to eliminate the nitrogen produced in the flowing system.