Determination of propoxur in environmental samples by automated solid-phase extraction followed by flow-injection analysis with tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection.
A sensitive method for the analysis of propoxur in environmental samples has been developed. It involves an automated solid-phase extraction (SPE) procedure using a Gilson Aspec XLi and flow-injection analysis (FI) with chemiluminescence (CL) detection. The FI-CL system relies on the photolysis of propoxur by irradiation using a low-pressure mercury lamp (main spectral line 254 nm). The resultant methylamine is subsequently detected by CL using tris(2,2'-bipyridyl)ruthenium(III), which is on-line generated by photo-oxidation of the ruthenium(II) complex in the presence of peroxydisulfate. The linear concentration range of application was 0.05-5 microg mL(-1) of propoxur, with a detection limit of 5 ng mL(-1). The repeatability was 0.82% expressed as relative standard deviation (n=10) and the reproducibility, studied on 5 consecutive days, was 2.1%. The sample throughput was 160 injection per hour. Propoxur residues below ng mL(-1) levels could be determined in environmental water samples when an SPE preconcentration device was coupled on-line with the FI system. This SPE-FI-CL arrangement provides a detection limit as low as 5 ng L(-1) using only 500 mL of sample. In the analysis of fruits and vegetables, the detection limit was about 10 microg kg(-1).
Pérez-Ruiz
Tomás
T
Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia, Spain. tpr@um.es <tpr@um.es>
Martínez-Lozano
Carmen
C
García
María Dolores
MD
D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives / Q000737:chemistry; D001937:Brassica / Q000737:chemistry; D056831:Coordination Complexes; D018553:Cucumis sativus / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis*; D017022:Flow Injection Analysis; D005456:Fluorescent Dyes / Q000737:chemistry; D007306:Insecticides / Q000032:analysis*; D008163:Luminescent Measurements; D027845:Malus / Q000737:chemistry; D001074:Propoxur / Q000032:analysis*; D031989:Pyrus / Q000737:chemistry; D052616:Solid Phase Extraction; D017975:Ruthenium Compounds
D015082:2,2'-Dipyridyl; D056831:Coordination Complexes; D004785:Environmental Pollutants; D005456:Fluorescent Dyes; D007306:Insecticides; D001074:Propoxur; C547232:tris(2,2-bipyridine)-ruthenium(II); D017975:Ruthenium Compounds