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不同学者用磷酸平衡法分析古哺乳动物牙齿化石碳酸羟基磷灰石中结构碳酸盐的碳、氧稳定同位素组成时,预处理方法和实验条件也不尽相同。实测结果表明,预处理条件与磷酸法制备CO2的反应温度和反应时间均可能对分析结果产生影响,需在综合运用机械和化学手段除净外表附着碳酸盐的前提下,将样品充分研磨,并彻底分解其中的有机组分和非结构碳酸盐,再制备CO2。70℃的恒温水浴可以使化学反应和同位素分馏均在短时间内结束,且较为完全、彻底,测得的同位素数据重现性好;而25℃时反应进行较缓,氧同位素测试结果有时可能不理想。
Different scholars use phosphoric acid balance method to analyze the carbon and oxygen stable isotopic composition of structural carbonate in ancient mammalian fossil carbonated hydroxyapatite, the pretreatment methods and experimental conditions are not the same. The experimental results show that the pretreatment conditions and phosphoric acid preparation of CO2 reaction temperature and reaction time may have an impact on the analysis results, the need to use mechanical and chemical means in addition to the net appearance attached to the premise of the carbonate, the sample is fully ground, And thoroughly decompose the organic components and unstructured carbonates, and then prepare a constant temperature water bath at 70 ℃ .The chemical reaction and isotopic fractionation can be completed in a short time, and more complete and complete, the measured isotope data weight Reality is good; while the reaction is slow at 25 ° C, oxygen isotope test results may not be ideal at times.