【摘要】：土壤中碳酸氫鈉提取的無(wú)機(jī)磷(Olsen-P)是可被植物吸收利用的有效磷.利用磷酸鹽中~(18)O和~(16)O組成(δ~(18)O-P)開(kāi)展土壤磷來(lái)源示蹤和磷循環(huán)轉(zhuǎn)化,具有重要意義.選擇0.5 mol·L~(-1)Na HCO_3(pH 8.5)溶液并加入無(wú)磷活性炭提取土壤磷,通過(guò)Mg(OH)_2-PO_4共沉淀、磷酸鈰沉淀等過(guò)程分離純化其中磷酸鹽,獲得磷酸銀沉淀,利用元素分析儀-穩(wěn)定性同位素比例質(zhì)譜儀測(cè)定氧同位素組成δ~(18)O-P值.結(jié)果表明:分離純化沉淀3個(gè)關(guān)鍵過(guò)程中磷酸鹽的回收率均能達(dá)到93%以上,損失較少,未出現(xiàn)氧同位素分餾.X射線衍射儀和氧含量測(cè)定表明,實(shí)驗(yàn)獲取的磷酸銀樣品純度較高.加入無(wú)磷活性炭可有效去除有機(jī)質(zhì)對(duì)δ~(18)O-P測(cè)定影響.供試黑土和潮土中碳酸氫鈉提取態(tài)土壤無(wú)機(jī)磷酸鹽δ~(18)O-P值分別為17.64‰±1.03‰和18.20‰±0.83‰,差異不明顯.本文建立土壤碳酸氫鈉提取態(tài)無(wú)機(jī)磷酸鹽中氧同位素分析測(cè)定方法,為農(nóng)田土壤中磷的循環(huán)轉(zhuǎn)化及其溯源研究提供技術(shù)支撐.
[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 鹵1.03 鈥，

本文編號(hào)：2327041