Preliminary validation of a sequential fractionation method to study phosphorus chemistry in a calcareous soil
Preliminary validation of a sequential fractionation method to study phosphorus chemistry in a calcareous soil
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DOI：
10.1016/j.chemosphere.2016.03.014
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发表时间：
2016-06-01
期刊：
影响因子：
8.8
通讯作者：
Voroney, R. Paul
中科院分区：
文献类型：
--
作者：
Audette, Yuki;O'Halloran, Ivan P.;Voroney, R. Paul
Jiang和Gu（1989）提出的连续分级方法根据植物有效性的不同区分了三种类型的磷酸钙（Ca-P）。用NaHCO 3、NH 4Ac和H2SO 4三种提取剂分别提取土壤中的Ca-2-P、C-8-P和Ca-10-P。这种连续的分馏方法进行了测试和修改，用于分析石灰性土壤的磷化学。溶解度试验和主要钙磷矿物稳定性模型图表明，NaHCO 3能萃取透钙磷石（Ca-2-P型），NH 4Ac能萃取透钙磷石、β-三钙磷（C-8-P型）和羟基磷灰石（Ca-10-P型）。因此，用NH 4Ac提取的目标P形式应包括Ca-8-和Ca-10-P类型。在石灰性土壤中，各提取剂连续分级法提取的P之和与高氯酸消解法测定的全P一致。通过连续分级方法测量的有机P的比例与溶液P-31 NMR光谱的结果一致。这项研究表明，修改后的连续分馏方法及其目标P形式将是有用的定量和表征无机和有机磷在石灰性土壤中，即使它应该与其他技术，如溶液P-31 NMR光谱结合使用。(C)2016爱思唯尔有限公司版权所有
A sequential fractionation method proposed by Jiang and Gu (1989) distinguished three types of calcium phosphates (Ca-P) according to their different plant availabilities. Three extractants, NaHCO3, NH4Ac, and H2SO4 were used to extract Ca-2-P, C-8-P, and Ca-10-P types, respectively, from soil. This sequential fractionation method was tested and modified for analyzing the P chemistry of a calcareous soil. The solubility test and the model diagrams of the stability of the major Ca-P minerals showed that NaHCO3 was able to extract brushite (Ca-2-P type), and NH4Ac extracted brushite and beta-tricalcium P (C-8-P type) as well as hydroxyapatite (Ca-10-P type). Therefore the P forms targeted by extraction with NH4Ac should include both Ca-8-and Ca-10-P types. The sum of the P extracted by all extractants in the sequential fractionation method in the calcareous soil was in agreement with the total P measured by the perchloric acid digestion method. A proportion of organic P measured by the sequential fractionation method was in agreement with the result from solution P-31 NMR spectroscopy. This study showed that the modified sequential fractionation method and its target P forms would be useful for quantifying and characterizing inorganic and organic P in a calcareous soil, even though it should be used in combination with other techniques, such as solution P-31 NMR spectroscopy. (C) 2016 Elsevier Ltd. All rights reserved.