Synthesis Of Novel Sorbents For Solid-phase Extraction And Their Adsorption Properties For Trace Class B Metal Ions In Solution Samples

As technology’s progress and economic development, water pollution due to Class B metals in industry wastewaters has become a major issue worldwide. It is vital important to determinate Class B metal ions exactly in the environmental samples. Direct determination of trace and ultra trace Class B metals at low concentrations by inductively coupled plasma optical emission spectrometry (ICP-OES) is often difficult, not only became of the insufficient sensitivity of the methods, but also because of matrix effects. Hence, preconcentration is required in order to bring the concentration of the analytes into the range of the detector, while separation is called for to eliminate potentially interfering matrix constituents. This requires SPE sorbent materials possess high selectivity and relatively large adsorption capacity, and then use the appropriate method for separation and enrichment of trace elements in the matrix. In this paper, three new adsorption materials are synthesized. The methods for synthesis of the adsorption materials and the adsorption selectivity characteristics for trace Class B metal ions have been investigated systematically. The more detailed novelty of this study can be categorized as following:1. A new solid sorbent, bentonite modified with2-((2-hydroxyethyl)amino)acetamide, was prepared and studied for sepration and preconcentration of Hg(II). A reliable method is established for determination of trace Hg(II). Experimental results revealed that the maximum adsorption capacity of this sorbent for Hg(II) was61.87mg g-1at pH1.0. The detection limit of the method was0.10ng mL-1, and the relative standard deviation was3.2%. Moreover, the methodology was validated by analyzing certified reference materials and successfully applied to the determination of trace Hg(II) in nature water samples with satisfactory results.2. Activated carbon was modiefied with L-cysteine. Then the new material was used for separation and enrichment of trace amounts of Pb(II). This method displaying high sensitivity and good selectivity was successfully used in analysis of environmental samples with good results.3. A new sorbent prepared by immobilizing creatine on activated carbon was successfully synthesized and then used for separation/preconcentration of trace Hg(II) prior to detection by inductively coupled plasma optical emission spectrometry (ICP-OES). Experimental conditions including pH, sample flow rate and volume, eluting variables and tolerance limit of interfering ions were evaluated and established. An enrichment factor of100was obtained for Hg(II). The maximum adsorption capacity was0.283mmol g-1. Under the optimal conditions, the value of the detection limit (3σ) was0.06ng mL-1, and the relative standard deviation (RSD) calculated was lower than3.0%(n=8). The methodology was validated by analyzing certified reference materials and successfully applied to the determination of trace Hg(II) in nature water samples with satisfactory results.