Synthesis Of Novel Adsorption Materials And Their Adsorption Properties For Trace Elements In Solution Samples

With the rapid development of economy, the pollution caused by heavy metalsbecomes more severe, which is also a dominant factor for jeopardizing the publichealth and preventing social economical development of our country. The accuratedetermination of trace element in geological, biological and environmental samples isan important and challenging task in analytical chemistry; especially heavy metals areoften routinely monitored in environmental water. Although many instrument analysismethods have been developed recently and reached trace level or super trace levelsensitivity, the direct analysis is still difficult because of the high complexity ofsamples and severe interference caused by matrix effects. For this reason, thepreliminary separation and preconcentration of trace elements from matrix using highselectivity and adsorption capacity with suitable method is often required.In this research paper, several new adsorption materials are synthesized in orderto pre-concentration and separation of trace components. Their adsorption andselectivity characteristics for trace components have been investigated systematically.The more detailed novelty of this research can be categorized as following:1. Nanometer SiO₂ and silica gel was modified with acetylsalicylic acid (aspirin),curcnmin and ofloxacin under the silane coupling agent (APS) and used forpreconcentration and separation of trace amounts of Cr(â…¢), Cu(â…¡), Fe(â…¢), Pb(â…¡),Ni(â…¡) and Zn(â…¡) from solution samples prior to their determination by inductivelycoupled plasma optical emission spectrometry (ICP-AES). The separation/preconcentration conditions of analytes, which include the effects of the pH, thesample flow rate and volume, the elution condition, detection limits and precision andthe interfering ions on the recovery of the analytes were investigated in detail. Theaccuracy of the proposed each method was checked by analyzing standard referencematerial with satisfactory results.2. The new adsorbent was prepared using glutamic acid (GA) impregnatedactivated carbon (AC) followed by activating agent of NaOH. The modified activatedcarbon with glutamic acid (AC-GA) was used as an adsorbent for the solid-phaseextraction (SPE) of trace amounts of Pb(â…¡) and Hg(â…¡) from solution samples prior totheir determination by inductively coupled plasma optical emission spectrometry (ICP-AES). The separation/pre-concentration conditions of analytes were investigatedin detail. This sorbent was used in analysis of water samples and the results aresatisfactory.3. The imprinted and non-imprinted polymers for Pb(â…¡) were obtained by a surfaceimprinting technique for selective solid-phase extraction (SPE) of Pb(â…¡) and prior toits determination by ICP-AES. The separation/pre-concentration conditions ofanalytes were investigated in detail with reliable and satisfactory results. The substrateselectivity of imprinted polymer and non-imprinted polymer was investigated. Theresults showed that the imprinted polymer exhibited much higher affinity for Pb(â…¡).4. Multi-wall carbon nanotubes were modified with diethylenetriamine(DETA)under the condensation agent of N,N'-dicyclohexylcarbodiimide and used forpreconcentration and separation of trace amounts of Cr(â…¢), Fe(â…¢), Pb(â…¡) and Mn(â…¡)from solution samples prior to their determination by inductively coupled plasmaoptical emission spectrometry (ICP-AES). The separation/preconcentration conditionsof analytes were investigated in detail. This sorbent was used in analysis of watersamples and the results are satisfactory.