Chemiluminescence determination of carbofuran and promecarb by flow injection analysis using two photochemical reactions

Abstract

A flow injection-chemiluminescent method for the determination of carbofuran and promecarb is proposed. The assay was based on the on-line conversion of the pesticides into methylamine by irradiation with UV light. The methylamine generated was subsequently reacted with tris(2,2′-bipyridine)ruthenium(III), which was generated through the on-line photo-oxidation of tris(2,2′-bipyridine)ruthenium(II) with peroxydisulfate. The emitted light showed a linear relationship with the concentration of the pesticide over the ranges 0.22–11.2 μg ml⁻¹ for carbofuran and 0.41–16.6 μg ml⁻¹ for promecarb. The repeatability was 1.6% expressed as relative standard deviation (n = 10) and the reproducibility, studied on five different days, was 2%. The sample throughput was 200 injections per h. The reliability of the method for routine analysis of these pesticides in water, soil and grains is demonstrated.