Study On Preparation Of Ion Imprinting Polymer Electrochemical Sensor And Its Application Of Heavy Metal Ions Detection Analysis

With the rapid development of economy and the blossom of industrial processing,battery manufacturing,mining and other industries,heavy metal ions from by-products in the production,polluted water and soil are increased,influencing biological metabolism and depositing in living body.It is harmful for the growth of animals and plants seriously.Lead ions as a common heavy metal ions,accumulate in the body impact blood circulatory system injuring various tissues and organs lesions.Especially It is damaged seriously to children and pregnant women even causing central nervous system disorders.Therefore,it is significant to detect the lead ions.In this thesis,the Pb²⁺is the template ions,the preparations are as follows:?1?The preparation of Pb²⁺ ions mesoporous silica electrochemical sensor has solved the IIPs prepared by precipitation polymerization in the second chapter,solving the problems of embedding cavities.At the same time,specific surface area increases,It is advantageous to the adsorption of ion imprinted polymer for the template.?2?Using the surface imprinting technology and sol-gel technology,prepared the polymerization of lead ions based on chitosan as functional monomer,assembling the Pb²⁺imprinted polymer electrochemical sensor.Not only solved the problem of embedding too deep,but also the template ion elute easily.Three ways to construct the Pb²⁺ion imprinted electrochemical sensors and the conditions of optimization selection are as follows:?1?The synthesis and preparation of unleached IIPs was by precipitation polymerization,which were made of lead ions as the template,methacrylic acid as the function monomer.The unleached IIPs were washed by plenty ethanol,HCl solution and thiourea solution to form the leached IIPs.The polymers were characterized.The prepared IIPs,paraffin oil and graphite powder were used to constitute the IIP-CPE,which the the optimal composition is 20%/30%/50%.Through the optimization of the detective conditions of lead ions imprinted polymers electrochemical sensor,at extraction potential is-1.0V,pH=5,in 0.1 mol L-1acetic acid-sodium acetate bufferincluding 5.0 x 10-7mol L-1lead ions to extract lead ions in HCl solution,the extraction time is 80 s and the pre-potential time is 40 s.It has a good response of peak current.The linear of the introduce sensor was from7.5×10-7to 1.0×10-9mol L-1and the limit of detection?LOD?was 1.3×10-11 mol L-1?S/N=3?.The sensor was successfully applied to the trace determination of lead ions in various real samples.?2?The synthesis and preparation of Pb²⁺ion imprinted mesoporous silica was by surface imprinting technology,which were made of lead ions as the template,3-??-aminoethylamino?-propyl-trimethoxysilane?AAPTS?as the function monomer.The unleached Pb²⁺ion imprinted mesoporous silica were refluxing in an ethanol/HCl?8:2,v/v?solution and washed by double deionized water to form the leached Pb²⁺ion imprinted mesoporous silica?Pb-IMS?.The polymers were characterized.The prepared Pb-IMS,paraffin oil and graphite powder were used to constitute the IIP-CPE,which the the optimal composition is 20%/20%/60%.Through the optimization of the detective conditions of lead ions imprinted polymers electrochemical sensor,at extraction potential is-1.2V,pH=5,in 0.1 mol L-1acetic acid-sodium acetate buffer including 5.0 x 10-7mol L-1lead ions to extract lead ions in HCl solution,the extraction time is 240 s and the pre-potential time is 40 s.It has a good response of peak current.The linear of the introduce sensor was from 1.0×10-6to1.0×10-9mol L-1and the limit of detection?LOD?was 2.03×10-11 mol L-1?S/N=3?.The sensor was successfully applied to the trace determination of lead ions in various real samples.?3?The synthesis and preparation of unleached IIPs was by surface imprinting technology and sol-gel technology,which were made of lead ions as the template,chitosan as the function monomer.The unleached IIPs were washed by plenty HCl solution,NaOH solution to adjust to neutral and using double deionized water to form the leached IIPs.The polymers were characterized.The prepared IIPs,paraffin oil and graphite powder were used to constitute the IIP-CPE,which the the optimal composition is 35%/20%/45%.Through the optimization of the detective conditionsof lead ions imprinted polymers electrochemical sensor,at extraction potential is-0.8V,pH=5,in 0.1 mol L-1acetic acid-sodium acetate buffer including 5.0 x 10-7mol L-1lead ions to extract lead ions in HCl solution,the extraction time is 240 s and the pre-potential time is 50 s.It has a good response of peak current.The linear of the introduce sensor was from 1.0×10-6to 1×10-9mol L-1and the limit of detection?LOD?was 2.93×10-10 mol L-1?S/N=3?.The sensor was successfully applied to the trace determination of lead ions in various real samples.