Potential of the luminol reaction in the sensitive detection of pesticide residues by flow injection analysis.
This study presents the first analytical application of the luminol chemiluminescence (CL) reaction for the sensitive detection of carbamate residues. Some experiments have been carried out to check the influence of the presence of traces of a N-methylcarbamate (carbaryl) on the CL emission produced from the oxidation of luminol using different oxidants, showing a significant enhancing effect on the CL emission when the oxidation of luminol is produced by potassium permanganate in alkaline medium, this enhancement being proportional to the carbaryl concentration. This fact has permitted the establishment of a sensitive chemiluminescence flow-injection (CL-FIA) method for the direct determination of carbaryl. The optimization of instrumental and chemical variables influencing the CL response has been carried out by applying experimental designs. Under the optimal conditions, the CL intensity was linear for a carbaryl concentration over the range 5-100 ng/mL with a detection limit of 4.9 ng/mL. This luminol-KMnO4-based FIA-CL system in basic medium shows an easy, fast and cheap alternative detection mode for the analysis of carbaryl residues in environmental water samples.
Department of Analytical Chemistry, Faculty of Sciences, University of Granada, E-18071 Granada, Spain.
José Fernando
JF
Huertas-Pérez
Ana M
AM
García-Campaña
Antonio
A
González-Casado
Laura
L
Gámiz-Gracia
D017022:Flow Injection Analysis / Q000379:methods*; D049449:Luminescence; D008165:Luminol / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis*; D012680:Sensitivity and Specificity; D014867:Water / Q000737:chemistry
D010573:Pesticide Residues; D014867:Water; D008165:Luminol