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 citratecapped 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 (Hg22+) and cadmium (Cd2+). 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 InfraRed (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 leaveoneout crossvalidation utilizing prediction residual error sum of square (PRESS). The linear range was in the range of 3.33 × 105 3.33 × 106 mol L1 and 2.0 × 105 1.0 × 106 mol L1, the detection limit was 1.21×107 and 0.5 ×107 mol L1 (n=5) for Hg22+and Cd2+, respectively. This method used successfully for simultaneous determination of Hg22+ and Cd2+ in West Azerbaijan regional waters namely Zarineh / Simineh rivers and Urmia Lake.