Chemiluminescent Determination of the Pesticide Bromoxynil by On-line Photodegradation in a Flow-Injection System

• Published in: Analytical Sciences 2006, Vol.22(1), pp.29-34
• Main Authors: PAWLICOVÁ, Z., ALBERT-GARCÍA, J. R., SAHUQUILLO, I., MATEO, J. V. GARCÍA, ICARDO, M. CATALÁ, CALATAYUD, J. MARTÍNEZ
• Format: Article
• Language: English
• Subjects: Flow Injection Analysis - instrumentation; Flow Injection Analysis - methods; Hydrogen-Ion Concentration; Luminescent Measurements - instrumentation; Luminescent Measurements - methods; Molecular Structure; Nitriles - analysis; Photochemistry; Sensitivity and Specificity
• ISSN: 0910-6340; 1348-2246
• DOI: 10.2116/analsci.22.29

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.