Simultaneous Voltammetric Determination of Lead and Tin by Adsorptive Differential Pulse Stripping Method and Orthogonal Signal Correction‐Partial Least Squares in Water Samples

Abstract

An adsorptive differential pulse stripping method for the simultaneous determination of lead and tin is proposed. The procedure involves an adsorptive accumulation of lead and tin on a hanging mercury drop electrode (HMDE), followed by oxidation of adsorbed lead and tin by voltammetric scan using differential pulse modulation. The optimum experimental conditions are: 0.2 mol L−1 HNO3, accumulation potential of −900 mV versus Ag/AgCl, accumulation time of 200 s, scan rate of 20 mV s−1 and pulse height of 80 mV. Lead and tin peak currents were observed in the same potential region at about −400 mV. The simultaneous determination of lead and tin by using voltammetry is a difficult problem in analytical chemistry, due to voltammogram interferences. The resolution of a mixture of lead and tin by the application of orthogonal signal correction‐partial least squares (OSC‐PLS) was performed. The linear dynamic ranges were 0.003‐0.35 and 0.008‐0.50 μg mL−1 and detection limits were land 3 ng mL−1 for lead and tin, respectively. The RMSEP for lead and tin with OSC and without OSC were 2.8737, 6.0557 and 8.0941, 9.5151, respectively. The capability of the method for the analysis of real samples was evaluated by the determination of lead and tin in water samples with satisfactory results.

Simultaneous determination of lead and tin at the bismuth film electrode by square wave stripping voltammetry and chemometric methods

“…Paola 37 showed that multivariate linear regression coupled with successive projections algorithm (SPA-MLR) was an effective tool to provide qualitative interpretations as well as quantitative predictions for the voltammetric determination of heavy metals under complex conditions. Ali Niazi et al 38,39 compared partial least squares (PLS), orthogonal signal correction-partial least squares (OSC-PLS) and least-squares support vector machines (LS-SVM) to obtain the signals of lead and tin resolved at the HDME and thus determined them simultaneously. There are, however, few papers concerning the research on the resolution problem of these metals at the BiFE combined with chemometric methods.…”