Optimization approach of pretreatment methods for phosphate oxygen isotopic analysis in freshwater

被引：1

作者：

Xue K. ^{[1
,2
]}

Zhang R. ^{[1
]}

An N. ^{[1
]}

Chen J. ^{[1
]}

Zou Y. ^{[1
]}

Liu Y. ^{[1
,2
]}

Zhang Z. ^{[1
,2
]}

机构：

[1] Institute of Geochemistry, Chinese Academy of Sciences, Guiyang

[2] University of Chinese Academy of Sciences, Beijing

来源：

Hupo Kexue/Journal of Lake Sciences | 2021年 / 33卷 / 01期

关键词：

Freshwater environment; Improvement; Phosphate oxygen isotope; Phosphorus; Pretreatment method;

D O I：

10.18307/2021.0127

中图分类号：

学科分类号：

摘要：

Phosphorus (P) is one of the key nutrients in surface water, and plays a vital role in the material cycle and energy flow in aquatic ecosystems. Hence, it is of great significance to explore the source, transformation, and fate in water body for understanding its evolution process and scientific protection of water environment. Recently, phosphate oxygen isotope technology (δ18OP) has been gradually applied in tracing the P source and studying the biogeochemical cycle in freshwater environment, which most used the sample pretreatment of seawater methods. By contrast, the concentrations of PO43- in freshwater samples are usually low, whereas the contents of organic matter and interference ions are high. The pretreatment complexity restricted the extensive application of δ18OP analysis in freshwater ecosystems. This study examined the applicability of the existing pretreatment methods of seawater sample in surface freshwater environment, and further carried out three optimization improvements: ①We replaced MgCl2 solution with Mg(NO3)2 solution in the MAGIC precipitation step to avoid the interference of Cl- and the impurities of AgCl. ②The solution pH value of Ag3PO4 precipitation was adjusted to 8.0 to ensure the rapid and complete precipitation. ③Possible photolysis effects of AgNO3 and Ag3PO4 were inhibited by using light avoidance. This modification improved the purity of Ag3PO4, and attained more accurate δ18OP results. The present method gives a valuable reference to further study of the biogeochemical cycle and eco-effects of P in freshwater environment using δ18OP analysis. © 2021 by Journal of Lake Sciences.

引用

页码：319 / 326

页数：7

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