Photodegradation and flow-injection determination of dithiocarbamate fungicides in natural water with chemiluminescence detection.

A simple and rapid flow-injection method is reported for the determination of dithiocarbamate fungicides (maneb, nabam and thiram) based on chemiluminescence detection. The method involves the photodegradation of dithiocarbamate fungicides via UV light in an alkaline medium. Photoproducts are then reacted with luminol in the absence of an oxidant. Linear calibration graphs were obtained in the range 0.01 - 4.0 mg L(-1) for maneb and nabam and 0.05 - 1.0 mg L(-1) for thiram with relative standard deviations (n = 4) in the range 1.0 - 2.6%. The detection limits (S/N = 3) of maneb, nabam and thiram were 10, 8.0 and 5.0 ng mL(-1), respectively, with a sample throughput of 100 h(-1). The method was successfully applied to determine these dithiocarbamate fungicides in spiked natural water samples.