Determination of Trace Amounts of Gold in Environmental Samples by Adsorptive Stripping Voltammetry of Its Complex with Rhodamine Using Osc-Pls

The multivariate calibration method was applied for the determination of trace amounts of gold based on a hanging mercury drop electrode (hmde) in the presence of rhodanine, followed by reduction of adsorbed gold by voltammetric scan using differential pulse modulation the optimum experimental conditions are: rhodanine concentration of 0.20 µg ml^-1, ph 5.0, accumulation potential of -600 mv versus ag/agcl, accumulation time of 100 sec, scan rate of 30 mv s^-1 and pulse height of 100 mv. the calibration matrix for partial least squares (pls) regression was designed with 9 samples. orthogonal signal correction (osc) is a preprocessing technique used for removing the information unrelated to the target variables based on constrained principal component analysis. osc is a suitable preprocessing method for pls calibration without loss of prediction capacity using electrochemical method. the rmsep for gold determination with pls and osc-pls were 8.51 and 1.94, respectively. this procedure allows the determination of gold in synthetic and real samples with good reliability of the determination.