Rieckmann Maria Monrad, Blake Ruth Elaine, Chang Sae Jung, Laursen Kristian Holst
Department of Plant and Environmental Sciences (PLEN), Faculty of Science, Plant and Soil Science Section, Plant Nutrients and Food Quality Research Group, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Copenhagen, Denmark.
Yale University, New Haven, CT, USA.
MethodsX. 2024 Jan 4;12:102541. doi: 10.1016/j.mex.2023.102541. eCollection 2024 Jun.
Compound-specific stable isotope ratio analysis of oxygen isotopes in inorganic phosphate can be used to study biological phosphorus cycling and the transformation processes controlling the fate of phosphorus. However, methods for extraction of inorganic phosphate from plant tissue for oxygen isotope ratio analysis are not consistent. Further, the purification into solid silver phosphate can be challenging and laborious. In this work, a detailed and optimized method to provide a more consistent, easily implementable and reproducible extraction using trichloroacetic acid and subsequent purification of inorganic phosphate from plant material for oxygen isotope ratio analysis is presented. Key focus points were: uniform extraction of inorganic phosphate from barley leaves, removal of dissolved organic material, flexibility in regards to the amount of inorganic phosphate extracted for the purification into silver phosphate, reduced use of chemicals and, removal of co-precipitated oxygen-bearing compounds before analysis. Most notable optimizations to the method and associated effects were:•Drying of plant material before inorganic phosphate extraction increases the method applicability to a broader range of plant sample types.•Removal of dissolved organic matter improves inorganic phosphate purification.•Sample volume adjustment according to inorganic phosphate content is vital for effective and quantitative precipitations.
无机磷酸盐中氧同位素的化合物特异性稳定同位素比率分析可用于研究生物磷循环以及控制磷归宿的转化过程。然而，从植物组织中提取无机磷酸盐用于氧同位素比率分析的方法并不一致。此外，将其纯化为固体磷酸银可能具有挑战性且费力。在这项工作中，我们提出了一种详细且优化的方法，该方法使用三氯乙酸提供更一致、易于实施且可重复的提取方法，并随后从植物材料中纯化无机磷酸盐用于氧同位素比率分析。关键要点包括：从大麦叶片中均匀提取无机磷酸盐、去除溶解的有机物质、在将无机磷酸盐纯化到磷酸银过程中提取量的灵活性、减少化学试剂的使用以及在分析前去除共沉淀的含氧化合物。该方法最显著的优化及相关效果如下：
在无机磷酸盐提取前对植物材料进行干燥处理，可扩大该方法对更广泛植物样品类型的适用性。
去除溶解的有机物质可改善无机磷酸盐的纯化效果。
根据无机磷酸盐含量调整样品体积对于有效且定量的沉淀至关重要。
