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同位素比值最精确的测量方法是质谱分析方法。它能在极其微小的变化范围内测定同位素的含量和差异。当然,只有在客观地计算测量误差及恰当的数据处理时,才能给予同位素分析数据的正确解释。 用质谱计测定碳酸盐中碳、氧同位素的δ值,其测量值(δ测)不等于真值(δ真),常常差一个系数K,即δ真=K·δ测。决定K值的因素有:仪器的系统误差、工作状态及外界条件等因素。实验数据的精密度和准确度,还决定于制样方法本身的分馏效应及其数据的处理。前者可以采用双标准方法测
The most accurate measurement of isotope ratio is the mass spectrometry method. It determines isotopic amounts and differences over very small ranges. Of course, correct interpretation of isotopic data can only be given when objectively calculating measurement errors and appropriate data processing. The δ value of carbon and oxygen isotopes in carbonate is measured by mass spectrometry. The measured value (δ measurement) is not equal to the true value (δ true), often by a factor K, that is, δ true = K · δ. Factors that determine the value of K are: system error of the instrument, working conditions and external conditions and other factors. The precision and accuracy of the experimental data also depend on the fractionation effect of the sample preparation method and its data processing. The former can use double standard method to measure