Photo-induced chemiluminescence determination of the pesticide Buminafos by a Multicommutation flow-analysis assembly

The preliminary experiments in this paper deal with the photo-induced chemiluminescent behaviour of Buminafos family, after the experimental screening tests and several of them resulted positive the, herbicide Buminafos was selected to develop a new analytical method. The determination of Buminafos was performed with the aid of a Multicommutation (a solenoid valve set) assembly. The method involves the on-line photo-degradation of the analyte (stopped flow, 5 s) with the selected Suitable medium (0.05% hydrogen peroxide) and its subsequent chemiluminescent oxidation by the potassium permanganate. Sample Solution alternated segments with the photo-degradation medium: and, after the irradiation, aliquots of the resulting mixture were alternated with the oxidant system. Both streams merged 2 cm before the flow-cell of the luminometer. The chemical optimization study was performed separately for photo-degradation and for oxidation by including different media and oxidants; it also included the study on the influence of sensitizers and tensoactive agents. Linear interval was from 0.01 to 1.0 mg l(-1) with a limit of detection of 0.005 mg l (1). Sample throughput and the reproducibility were 48 h(-1) and 3%, respectively. After testing the analytical figures of merit foreign compounds were Studied as possible interferents of the method. The proposed method was applied to the determination of the pesticide in spiked water and soil samples. (C) 2008 Elsevier B.V. All rights reserved.