Analytical Sciences


Abstract − Analytical Sciences, 22(1), 29 (2006).

Chemiluminescent Determination of the Pesticide Bromoxynil by On-line Photodegradation in a Flow-Injection System
Z. PAWLICOVÁ,* J. R. ALBERT-GARCÍA,* I. SAHUQUILLO,** J. V. GARCÍA MATEO,** M. CATALÁ ICARDO,*** and J. MARTÍNEZ CALATAYUD*
*Department of Analytical Chemistry, University of Valencia, Valencia, Spain
**Department of Chemistry, Biochemistry and Molecular Biology, University Cardenal Herrera-CEU, Moncada, Valencia, Spain
***Department of Chemistry, Polytechnic University of Valencia, Valencia, Spain
A new, robust and simple method is proposed for the chemiluminescent determination of the pesticide Bromoxynil. The empirical procedure is performed with the aid of a flow-injection manifold provided with an on-line photo-reactor to obtain chemiluminescent photofragments. After a period of 12 s of irradiation with an 8 W low-pressure mercury lamp, a chemiluminescent oxidation was performed with the system potassium permanganate in a polyphosphoric acid medium. The photolysis required a basic medium (KOH 0.014 mol l-1) with ethanol (1%) as a sensitizer. The method allowed the determination of 134 samples h-1 of Bromoxynil in a wide interval of concentrations, over the range 5 × 10-3 - 1 mg l-1; the detection limit was 5 × 10-3 mg l-1. The RSD (n = 24) at 0.25 mg l-1 of the pesticide level was 2.3%. The method was applied to a water sample and to a formulation.