The oxygen isotope ratio in phosphate (δ¹⁸O_P) is an effective tool for tracing the sources of phosphorus (P) and their biogeochemical cycles. The HCl-extractable inorganic phosphate (HCl-P_TI) is the primary component of P and plays a key role in the dynamic transformation of P in sediment and soil. However, it has always been difficult to purity sample for analyzing the δ¹⁸O_P composition of HCl-P_TI due to the significantly interference of large amounts of Fe^2+/3+, Ca²⁺, Cl⁻ and other impurities in the HCl-P_TI extracts. In this study, we developed a simple and promising purification method for δ¹⁸O_P analysis of HCl-P_TI in sediments and soils based on the superior selective enrichment and elution abilities of phosphate (PO₄) and efficient synchronous removal of impurities by Zr-Oxide gel in highly acidic HCl-P_TI extract. The enrichment rate and elution rate of PO₄ in the HCl-P_TI extract by the Zr-Oxide gel could achieve 100% respectively, and the synchronous removal rates of most anions, dissolved organic carbon (DOC), metals, and trace elements could be above 96% respectively, reducing the tedious operation of conventional methods and the difficulties in removal of impurities, such as Cl⁻ in HCl-P_TI extract. It's indicated that the purity of the Ag₃PO₄ solid for δ¹⁸O_P composition analysis of HCl-P_TI could reach 99.9%. The above results show that the new method is very simple, efficient and reliable for the δ¹⁸O_P analysis of HCl-P_TI in sediments and soils. This study provides new methodological support for identifying the sources of P and tracing their biogeochemical cycles in sediment or soil environment.

在磷酸盐中的氧同位素比率（δ ¹⁸ ö _P）是用于跟踪磷（P）和它们的生物地球化学循环的源极的有效工具。HCl可萃取的无机磷酸盐（HCl-P _TI）是P的主要成分，在沉积物和土壤中P的动态转化中起关键作用。然而，它一直是困难的纯度样品用于分析δ ¹⁸ ö _P的HCl-P的组合物_TI由于大量Fe的显著干扰^{2 + / 3 +}，钙²⁺，氯^-和其它杂质在盐酸-_钛提取物。在这项研究中，我们开发了用于δ简单和有前途的纯化方法¹⁸ ö _P的HCl-P的分析_TI沉积物并且基于优越选择性富集土壤和洗脱能力磷酸盐（PO的₄由Zr）的和高效的同步去除杂质-高酸性HCl-P _TI提取物中的-Oxide凝胶。HCl-P _TI中PO ₄的富集率和洗脱率Zr-Oxide凝胶提取液可分别达到100％，大多数阴离子，溶解有机碳（DOC），金属和微量元素的同步去除率分别可达到96％以上，从而减少了传统方法的繁琐操作和在除去杂质，如Cl困难^-在HCl-P _TI提取物。它表明，Ag的纯度₃ PO ₄固体为δ ¹⁸ ö _P的HCl-P的组成分析_TI可达到99.9％。上述结果表明，该新方法是非常简单，有效和可靠的δ ¹⁸ ö _P的HCl-P的分析_TI在沉积物和土壤中。这项研究为确定磷的来源并追踪其在沉积物或土壤环境中的生物地球化学循环提供了新的方法学支持。