System Construction And Application Research Of The Preconcentration Device For Heavy Metal Ions

Heavy metal pollution directly affects human health and living environment. Usually the concentration of heavy metal ions in water is low, but the harm is huge. Therefore, it is of extraordinary significance to develop efficient analysis and detection methods of trace heavy metal ions for environmental monitoring, dealing with environmental pollution incidents and so on.In order to achieve the requirement of the detection sensitivity of analysis method, preconcentration is necessary before the detection of trace heavy metal ion in water. In the thesis, a novel preconcentration device based on field-amplified effect was designed for enriching heavy metal ions in water samples. To get better enrichment, free flow electrophoresis, capillary zone electrophoresis and field-amplified effect were utilized in the system. The transport characteristics of metal ions in the system were researched theoretically. The enrichment principles and influencing factors in the static and dynamic modes were studied to demonstrate the feasibility and superiority of the preconcentration method.A static preconcentration device based on field-amplified, using chelating resin of D401as adsorbent, was designed and constructed for enriching Pb(Ⅱ), Zn(Ⅱ) and Cu(Ⅱ) in water. Inductively coupled plasma-atomic emission spectrometry (ICP-AES) was used for detection. Various parameters, such as the concentration of background ionic solution, preconcentration time, pH values and the amounts of resin, were optimized to increase enrichment factor. Under the optimized conditions, the preconcentration factors for Cu(Ⅱ). Zn(Ⅱ). Pb(Ⅱ) were904,692and556, respectively. The recoveries were between62.6%～84.2%. The relative standard deviations of the determination were from5.2%to9.4%.Based on static preconcentration device, the dynamic preconcentration device was constructed. Several factors, such as the concentration of background ionic solution, preconcentration time, the amounts of resin, sample solution drop speed, platinum electrode type and organic additive, were studied. The research of the influences of these factors on enrichment efficiency establishes the foundation for further optimization of novel preconcentration device.