Application of multivariate curve resolution alternating least squares to biomedical analysis using electrochemical techniques at a nanostructure-based modified sensor

Application of multivariate curve resolution alternating least squares (MCR-ALS), for the resolution and quantification of two sulfonamide drugs containing sulfamethizole (SMT) and sulfapyridine (SPY) with a very high degree of overlapping voltammograms, is described. A simple and sensitive carbon nanocomposite electrode has been developed for the electrochemical trace determination of SMT and SPY in Britton-Robinson (B-R) buffer solution. This sensor was designed by incorporation of multi-walled carbon nanotubes (MWCNTs) into the carbon paste electrode (CPE). Response surface methodology (RSM) using central composite rotatable design (CCRD) model was used to optimize effective parameters on differential pulse voltammetry (DPV) response of the two analytes. A 4-factor-5-level CCRD of RSM was applied to model linear, interaction and quadratic effects of chemical and instrumental variables. After potential shift correction, MCR-ALS has been applied to data collected from DPV analysis of the oxidation process of SMT and SPY in different pulse heights. Quantitative voltammetric analyses of SMT and SPY were performed in the concentration range of 0.1-180.0 and 0.5-165.0 μM, and it was found that the detection limits were 50.0 and 60.0 nM, respectively. The method was applied for simultaneous determination of SMT and SPY in spiked human serum and urine samples.