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Kinetic and spectroscopic methods were used in combination in this work to develop a new analytical tool for use in chemiluminescence detection processes. Specifically, time-resolved chemiluminescence was used jointly with a stopped-flow assembly in order to monitor the chemiluminescence produced in the oxidation of bis(2,4-dinitrophenyl)oxalate (DNPO) by hydrogen peroxide in the presence of a polycyclic aromatic hydrocarbon. Recording of successive two-dimensional spectra during the emission process and treating the acquired spectral data with dedicated software allows the obtainment of three-dimensional chemiluminescence spectra, a result of the joint use of two analytical techniques. Thus, using a flow cell specifically designed for direct coupling to the charge-coupled device (CCD) detector increases the emission intensity without the need for fibre optics. Also, using dedicated software to process the acquired two-dimensional spectra affords a comprehensive kinetic and spectroscopic characterization of the chemiluminescence signal via the three-dimensional spectrum previously obtained. The analytical potential of this new tool was assessed by application to the chemiluminescent reaction between a peroxyoxalate and an oxidant (hydrogen peroxide); the reaction is induced by benzo(a)pyrene, which was used to determine this polycyclic aromatic hydrocarbon in an organic solvent. A linear calibration graph was obtained between 0.5 and 20 mg L(-1). The limit of detection found to be 3.97 μg L(-1) and a relative standard error of 0.64% and a relative standard deviation of 1.87% were obtained. The results reached testify to the usefulness of the proposed analytical tool for simple determinations and its potential for the resolution of complex mixtures or determinations in complex matrices., (Copyright © 2011 Elsevier B.V. All rights reserved.)

A novel alternative for the simultaneous determination of compounds with similar structure is described, using the whole chemiluminescence-time profiles, acquired by the stopped-flow technique, in combination with mathematical treatments of multivariate calibration. The proposed method is based on the chemiluminescent oxidation of morphine and naloxone by their reaction with potassium permanganate in an acidic medium, using formaldehyde as co-factor. The whole chemiluminescence-time profiles, acquired using the stopped-flow technique in a continuous-flow system, allowed the use of the time-resolved chemiluminescence (CL) data in combination with multivariate calibration techniques, as partial least squares (PLS), for the quantitative determination of both opiate narcotics in binary mixtures. In order to achieve overcoat the additivity of the CL profiles and beside to obtain CL profiles for each drug the most separated as possible in the time, the optimum chemical conditions for the CL emission were investigated. The effect of common emission enhancers on the CL emission obtained in the oxidation reaction of these compounds in different acidic media was studied. The parameters selected were sulphuric acid 1.0 mol L(-1), permanganate 0.2 mmol L(-1) and formaldehyde 0.8 mol L(-1). A calibration set of standard samples was designed by combination of a factorial design, with three levels for each factor and a central composite design. Finally, with the aim of validating the chemometric proposed method, a prediction set of binary samples was prepared. Using the multivariate calibration method proposed, the analytes were determined in synthetic samples, obtaining recoveries of 97-109%.