磷灰石核磁共振研究在土壤生态学中的应用
毕业论文关键词：磷灰石；磷元素地球化学循环；碳酸根替代；核磁共振技术；氢
Application of bioapatite to soil remediation and ecological effects by solid-state NMR spectra investigation
Abstract： Nuclear Magnetic Resonance has been widely applied in Ecology, Resources and Environmental Sciences studies. Phosphorus is mainly stored in apatite on Earth. Therefore, apatite is a kind of important material in studying the geochemical circulation of phosphorus. Bioapatite is one kind of apatite which exists in a variety of types. Its status that links biotic and abiotic phosphorus circulation makes it being an ideal resource in detecting the mechanism and application of bioapatite in phosphorus geochemical cycle. In addition, bioapatite is also a type of ideal resource in studying animal’s response to climate change for its high carbonate substitution in crystal lattice. In this experiment, hen’s femur at different age stages and hypermineralized rostrum with enriched carbonate incorporation, in addition to a series of synthetic calcium phosphates, are analyzed by 1H, 31P solid-state NMR spectroscopy. In addition, 1H-31P HetCor NMR spectroscopy was applied. 1H-31P HetCor spectra indicated that the enriched carbonate in the bioapatite have no regular correlation with the hydroxyl ion depletion. Therefore, there are limited effects on hydroxyls via the carbonate substitution. It is mineral crystallinity rather than CO32- substitution has direct connection to hydroxyl ion deficiency. Carbonate is assistant to reinforce H-bonding of hydroxyl ion.
Key words: Apatite, Phosphorus geochemical circulation；carbonate substitution; NMR, Hydrogen.
目 录
摘要1
关键词1
Abstract1
Key words1
引言（或绪论）1
1材料与方法3
1.1材料 3
1.2方法 3
2结果与分析4
2.1 拉曼光谱4
2.2 31P固体核磁共振图谱5
2.3 1H固体核磁共振图谱6
2.4 2D 1H-31P HetCor核磁共振图谱7
3 讨论8
3.1磷元素的存在形式-磷酸二氢根和磷酸氢根的存在8
3.2生物磷灰石中的脂质和水9
3.3碳酸根和羟基基团的相关性9
致谢10
参考文献10
图1 拉曼光谱4
图2 1H核磁共振图谱5
图3 31P核磁共振图谱 6
图4 1H-31P 2D HetCor核磁共振图谱7
图5 1H-31P 2D HetCor核磁共振1H轴投影图8
表1 1H核磁共振图谱化学位移5
表2 31P核磁共振图谱化学位移 7
磷灰石核磁共振研究在土壤生态学中的应用
引言：磷酸钙是地球上自然发生的最丰富的磷酸盐，是生产化肥和磷酸盐的重要材料之一。不同于氮、硫等元素，植物所必须的磷元素的唯一来源是植物根系对土壤中磷元素的吸收。在土壤中，羟基磷灰石中的磷约占土壤成分的90%。所以，羟基磷灰石对植物吸收土壤磷元素具有重要意义。另外，在土壤污染与水污染这一方面，利用矿物对重金属铅污染的治理在这几年来逐渐成为新兴的热点。有毒性的重金属铅元素在水源及土壤中的残留已经成为十分严峻的环境污染问题之一，严重威胁人类及其他生物的生命健康。[1-3]利用磷灰石治理铅污染有其本身巨大的优越性。磷灰石十分难溶（Ksp~10-70-10-80）。[3-5]尤其是在利用生物磷灰石治理土壤铅污染这一方面，生物磷灰石相比于氟基磷灰石的较高溶解度特性[6]使铅元素更容易固定在矿物晶格上，而铅元素一旦被固定在磷灰石矿物晶格上就很难发生解吸附作用。所以说对于Ca10(PO4)6(F,OH,Cl)2这一类型物质的研究是一项重要的涵盖范围广阔的科学研究（包括地球科学，生命科学，材料研究等等）。相比于其他手段，利用核磁共振技术研究磷灰石的磷元素测量得到的信息更加精确，不仅能够提供磷灰石中磷元素的存在形态类信息，还能够进行一定程度的量化。利用核磁共振技术研究土壤中磷元素的存在形态具有广泛的应用前景。