螯合肥稳定性及结构表征研究

近年来，随着农业集约化程度的不断提高，农业面源污染与农田土壤修复已成为农业研究中的重要内容，传统无机盐肥利用效率低下，“高效、环境友好型”的螯合肥研究与应用受到广泛关注。随着国际新形势下对土壤修复、农业面源污染减控等方面的重视，以及人们对高品质农产品需求的增加，螯合肥能否对此起到积极的促进作用，需要我们结合其稳定性、结构表征进行综合分析，从而为高端肥料市场的发展提供理论依据与数据支撑。螯合物稳定常数指螯合肥产品中已络合部分的稳定程度，我们可通过数学运算，如生成函数、来腾函数和福劳内乌斯函数等计算络（螯）合物的稳定常数。虽然迄今尚未建立统一的螯合肥稳定常数（或螯合强度）的测定标准方法，但国内外学者在这一领域做了大量的工作。但目前大多数测定方法尚不成熟，在稳定常数（或螯合强度）的定量参照数值的确定上也存在争议，且分析测定的螯合肥的方法以氨基酸螯合肥居多，对于非氨基酸螯合剂生成的螯合肥，需要进行综合评判以寻求测定各类配位体螯合物的标准方法。其次，结构决定性质，结构的表征有助于螯合肥的定性分析、实验现象的机理分析以及检测方法的选择。对于螯合物结构表征的方法，首先考虑的是螯合物单晶体或是纯品，但对于带有少量杂质的螯合物而言，数据可靠的结构表征手段往往无法快速构建。因此，在综合国内外相关研究的基础上，系统总结了螯合物稳定性测定与结构表征技术的研究，重点探讨各种技术手段的优缺点，提出螯合肥研究的发展方向，以期为螯合肥的科学开发与有效利用提供理论基础。

Stability and Structural Characterization of Chelated Fertilizers

In recent years, agricultural intensification and the need for reduced fertilizer application have rendered soil remediation and agricultural non-point-source pollution control globally significant. Compared to inefficiently utilized inorganic salt fertilizers, chelated fertilizers are more efficient and environmentally friendly, and have thus attracted considerable attention. In the new international context, more attention is being paid to soil remediation and reductions in agricultural non-point-source pollution, as the demand for high-quality agricultural products increases. Chelating fertilizers may play important roles in these contexts; models of stability and structure are required to provide both the theoretical basis for further development and data supporting continuing research and development. The stability constant reflects the stability of a chelated material; the stability constants of chelates can be calculated mathematically using the generating, Leden, and/or Fronaeus function (s). Although no standard method is yet available for the determination of stability constants, a great deal of relevant work has been performed worldwide. However, most methods are not yet mature, and appropriate stability constant reference values remain controversial. Since most of the fertilizers analyzed used amino acids for chelation, other ligands hardly received attention, potential applications of other ligands should be fully exploited. The molecular structure of a compound determines its properties. Structural characterization contributes to the qualitative analysis of chelated fertilizers, improves the understanding of experimental phenomena, and affects the selection of detective methods. The first consideration is whether the chelate is pure. Even if the levels of impurities are low, reliable structural data can be difficult to obtain. Therefore, we systematically summarize progress in how chelated fertilizer stability is assessed and how such fertilizers are structurally characterized. We focus on the advantages and disadvantages of various processes, outlining the need for future research. And we provide a theoretical basis for the development and effective utilization of chelated fertilizers.