Calconcarboxylic acid dynamically modified nanometer-sized zirconia for on-line flow injection-inductively coupled plasma optical emission spectrometry determination of trace heavy metals in environmental water samples

Abstract

A novel adsorbent was synthesized by grafting calconcarboxylic acid (CAA) dynamically to nanometer-sized zirconia (ZrO₂) and was characterized with a transmission electron microscope, nitrogen adsorption instrument and infrared spectroscopy. By using CAA modified nanometer-sized ZrO₂ as micro-column packing material, a new method of flow injection (FI) on-line preconcentration coupled with inductively coupled plasma optical emission spectrometry (ICP-OES) was developed for simultaneous determination of trace metals (Cd, Co, Cu, Ni and Pb) in environmental water samples. The experimental parameters including pH, sample flow rate and volume, elution volume and flow rate and coexisting ions on the extraction of the target analytes were investigated, and the optimal experimental conditions were established. Under the optimized operating conditions, the limits of detection (LODs) of this method for Cd, Co, Cu, Ni and Pb were 0.16, 0.04, 0.28, 0.22, and 0.95 ng mL⁻¹, with the relative standard deviations (RSDs) of 2.2, 3.0, 4.5, 4.1 and 7.7% (n = 7, c = 10 ng mL⁻¹), respectively. An enrichment factor of 10 and sampling frequency of 12 h⁻¹ were obtained by using a loading time of 200 s and elution time of 30 s. The proposed method was validated by analysis of the target metals in Certified Reference Materials of GSBZ50009-88 environmental water and real-world natural water samples.