Simultaneous chemiluminescence determination of amoxicillin and clavulanic acid using least squares support vector regression

In this work, both the batch and flow injection chemiluminescence (CL) methods have been proposed for the simultaneous determination of two structurally similar beta-lactams including amoxicillin and clavulanic acid (CLAV). Chemiluminescence spectral overlap of these two structurally similar beta-lactams is the main limitation for the simultaneous analysis of the two compounds. Least squares support vector regression (LS-SVR) was applied to relate concentration of both the compounds to their CL profiles. The parameters of the model, consisting of kernel parameter, sigma(2), and the regularization parameter, gamma, were optimized by constructing different LS-SVR models and the model with the minimum root mean squared error of cross-validation (RMSECV) for the calibration set was selected as the best model and its parameters were chosen as the optimized values. The performance of LS-SVR model was compared with Partial Least Squares (PLS) and the results revealed the superiority of the LS-SVR over PLS model. Under the optimized experimental conditions for both the compounds, when LS-SVR was applied, the detection limits obtained were 0.2 and 0.60 mu mol L-1 in the batch mode and 0.3 and 0.5 mu mol L-1 in the flow injection mode for CLAV and amoxicillin, respectively. The proposed method was utilized for the simultaneous determination of the compounds in pharmaceutical formulations and spiked plasma samples. (C) 2010 Elsevier B.V. All rights reserved.