selective and sensitive simultaneous determination of mercury and cadmium based on the aggregation of phca modified-aunps in west azerbaijan regional waters

The present study aims to present a new convenient sensor for heavy metals, based on aggregation of citrate-capped- n, n' biphenyl hydrazine 1, 2 dicarbothioamide (phca) - modified- (aunps). this paper reports a procedure for sensitive and selective spectrophotometric methods for simultaneous determination of mercury (hg2^2+) and cadmium (cd^2+). for this aim multivariate data including kinetic spectra of aunps were collected during aggregation process. the characterization of aunps was performed by transmission electron microscopy (tem) and infra-red (ir) spectroscopy. partial least square (pls) regression as an efficient multivariate calibration method was employed to make a connection between the surface plasmon resonance (spr) spectra of the generated aunps. the number of pls latent variables was optimized by leave-one-out cross-validation utilizing prediction residual error sum of square (press). the linear range was in the range of 3.33 × 10^-5 - 3.33 × 10^-6 mol l^-1 and 2.0 × 10^-5 - 1.0 × 10^-6 mol l^-1, the detection limit was 1.21×10^-7 and 0.5 ×10^-7 mol l^-1 (n=5) for hg2^2+and cd^2+, respectively. this method used successfully for simultaneous determination of hg2^2+ and cd^2+ in west azerbaijan regional waters namely zarineh / simineh rivers and urmia lake.