Determination of the pesticide carbaryl and its photodegradation kinetics in natural waters by flow injection–direct chemiluminescence detection

A novel flow injection–chemiluminescence method for the quantitative assay of the pesticide carbaryl in environmental samples is presented. The determination is based on the CL-emission generated by the oxidation of the pesticide with potassium permanganate. The linear response of CL-emission versus concentration is valid in the range from 0.01 to 1.0 μg mL−1, yielding detection limits (S/N = 3) as low as 14.8 ng mL−1. The method shows high reproducibility (R.S.D. = 2.29%, n = 10) and is subject to minor interferences from various organic and inorganic species likely to be found in natural waters. The suggested method is rapid and capable to be fully automated, thus resulting to a method of satisfactory sampling throughput, with low detection limits and efficient precision for routine analysis. The use of this technique to a new application of direct chemiluminescence involving the determination of carbaryl photodegradation in natural waters was successfully accomplished.