土壤碳酸氢钠提取态无机磷酸盐中氧同位素分析
发布时间：2018-11-12 11:55
【摘要】：土壤中碳酸氢钠提取的无机磷(Olsen-P)是可被植物吸收利用的有效磷.利用磷酸盐中~(18)O和~(16)O组成(δ~(18)O-P)开展土壤磷来源示踪和磷循环转化,具有重要意义.选择0.5 mol·L~(-1)Na HCO_3(pH 8.5)溶液并加入无磷活性炭提取土壤磷,通过Mg(OH)_2-PO_4共沉淀、磷酸铈沉淀等过程分离纯化其中磷酸盐,获得磷酸银沉淀,利用元素分析仪-稳定性同位素比例质谱仪测定氧同位素组成δ~(18)O-P值.结果表明:分离纯化沉淀3个关键过程中磷酸盐的回收率均能达到93%以上,损失较少,未出现氧同位素分馏.X射线衍射仪和氧含量测定表明,实验获取的磷酸银样品纯度较高.加入无磷活性炭可有效去除有机质对δ~(18)O-P测定影响.供试黑土和潮土中碳酸氢钠提取态土壤无机磷酸盐δ~(18)O-P值分别为17.64‰±1.03‰和18.20‰±0.83‰,差异不明显.本文建立土壤碳酸氢钠提取态无机磷酸盐中氧同位素分析测定方法,为农田土壤中磷的循环转化及其溯源研究提供技术支撑.
[Abstract]:Inorganic phosphorus (Olsen-P) extracted from soil by sodium bicarbonate is an available phosphorus that can be absorbed by plants. It is of great significance to use the composition of ~ (18) O and ~ (16) O in phosphate (未 ~ (18) O-P) to trace the source of phosphorus and to recycle phosphorus in the soil. 0. 5 mol L ~ (-1) Na HCO_3 (pH 8. 5) solution was used to extract phosphorus from soil. Phosphate was separated and purified by Mg (OH) _ 2-PO_4 coprecipitation and cerium phosphate precipitation. Silver phosphate precipitation was obtained and 未 ~ (18) O-P value of oxygen isotopic composition was determined by elemental analysis-stable isotope proportional mass spectrometer. The results showed that the recovery rate of phosphate in the three key processes of separation, purification and precipitation was over 93%, and the loss was less. There was no oxygen isotope fractionation. The X-ray diffractometer and the determination of oxygen content showed that the recovery rate of phosphate was more than 93%. The purity of silver phosphate sample was high. The effect of organic matter on 未 ~ (18) O-P determination can be effectively removed by adding phosphorus free activated carbon. The 未 ~ (18) O-P values of inorganic phosphate in black soil and tidal soil were 17.64 卤1.03 鈥，
本文编号：2327041
[Abstract]:Inorganic phosphorus (Olsen-P) extracted from soil by sodium bicarbonate is an available phosphorus that can be absorbed by plants. It is of great significance to use the composition of ~ (18) O and ~ (16) O in phosphate (未 ~ (18) O-P) to trace the source of phosphorus and to recycle phosphorus in the soil. 0. 5 mol L ~ (-1) Na HCO_3 (pH 8. 5) solution was used to extract phosphorus from soil. Phosphate was separated and purified by Mg (OH) _ 2-PO_4 coprecipitation and cerium phosphate precipitation. Silver phosphate precipitation was obtained and 未 ~ (18) O-P value of oxygen isotopic composition was determined by elemental analysis-stable isotope proportional mass spectrometer. The results showed that the recovery rate of phosphate in the three key processes of separation, purification and precipitation was over 93%, and the loss was less. There was no oxygen isotope fractionation. The X-ray diffractometer and the determination of oxygen content showed that the recovery rate of phosphate was more than 93%. The purity of silver phosphate sample was high. The effect of organic matter on 未 ~ (18) O-P determination can be effectively removed by adding phosphorus free activated carbon. The 未 ~ (18) O-P values of inorganic phosphate in black soil and tidal soil were 17.64 卤1.03 鈥，
本文编号：2327041
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