R&D Department, Timac Agro International, Polígono Arazuri-Orkoien, Orkoien, Navarra, Spain.
ChemSusChem. 2013 Jul;6(7):1245-51. doi: 10.1002/cssc.201300024. Epub 2013 May 13.
Fertilizers based on phosphate-metal-humate complexes are a new family of compounds that represents a more sustainable and bioavailable phosphorus source. The characterization of this type of complex by using solid (31)P NMR in several fertilizers, based on single superphosphate (SSP) and triple superphosphate (TSP) matrices, yielded surprising and unexpected trends in the intensity and fine structure of the (31)P NMR peaks. Computational chemistry methods allowed the characterization of phosphate-calcium-humate complexes in both SSP and TSP matrices, but also predicted the formation of a stable sulfate-calcium-humate complex in the SSP fertilizers, which has not been described previously. The stability of this complex has been confirmed by using ultrafiltration techniques. Preference towards the humic substance for the sulfate-metal phase in SSP allowed the explanation of the opposing trends that were observed in the experimental (31)P NMR spectra of SSP and TSP samples. Additionally, computational chemistry has provided an assignment of the (31)P NMR signals to different phosphate ligands as well as valuable information about the relative strength of the phosphate-calcium interactions within the crystals.
基于磷酸盐-金属-腐殖酸配合物的肥料是一类新型化合物，代表了一种更可持续和生物可利用的磷源。通过使用固态（31）P NMR 在几种基于过磷酸钙（SSP）和重过磷酸钙（TSP）基质的肥料中对这种配合物进行表征，在（31）P NMR 峰的强度和精细结构方面得出了令人惊讶和意外的趋势。计算化学方法不仅能够对 SSP 和 TSP 基质中的磷酸盐-钙-腐殖酸配合物进行表征，而且还预测了在 SSP 肥料中形成稳定的硫酸盐-钙-腐殖酸配合物，这是以前未曾描述过的。该配合物的稳定性已通过超滤技术得到证实。在 SSP 中，对硫酸盐-金属相的腐殖质的偏好解释了在 SSP 和 TSP 样品的实验（31）P NMR 光谱中观察到的相反趋势。此外，计算化学为不同的磷酸盐配体的（31）P NMR 信号提供了分配，并提供了有关晶体内部磷酸盐-钙相互作用相对强度的有价值信息。
