BAM Federal Institute for Materials Research and Testing, Unter den Eichen 87, 12205, Berlin, Germany.
Rapid Commun Mass Spectrom. 2012 Feb 15;26(3):275-81. doi: 10.1002/rcm.5306.
Triple IDMS has been applied for the first time to the quantification of element concentrations. It has been compared with single and double IDMS obtained on the same sample set in order to evaluate the advantages and disadvantages of triple IDMS over single and double IDMS as an analytical reference procedure. The measurement results of single, double and triple IDMS are indistinguishable, considering rounding due to the individual measurement uncertainties. As expected, the relative expanded uncertainties (k = 2) achieved with double IDMS (0.08%) are dramatically smaller than those obtained with single IDMS (1.4%). Triple IDMS yields the smallest relative expanded uncertainties (k = 2, 0.077%) unfortunately at the expense of a much higher workload. Nevertheless triple IDMS has the huge advantage that the isotope ratio of the spike does not need to be determined. Elements with high memory effects, highly enriched spikes or highest metrological requirements may be typical applications for triple IDMS.
三重 IDMS 首次被应用于元素浓度的定量分析。将三重 IDMS 与同一组样品的单重和双重 IDMS 进行比较，以评估三重 IDMS 相对于单重和双重 IDMS 作为分析参考方法的优缺点。考虑到由于个别测量不确定度导致的四舍五入，三重 IDMS、单重 IDMS 和双重 IDMS 的测量结果无法区分。如预期的那样，双 IDMS（0.08%）获得的相对扩展不确定度（k=2）明显小于单 IDMS（1.4%）获得的相对扩展不确定度。三重 IDMS 产生了最小的相对扩展不确定度（k=2，0.077%），但不幸的是，这是以更高的工作量为代价的。尽管如此，三重 IDMS 具有一个巨大的优势，即不需要确定内标同位素的同位素比值。具有高记忆效应、高度富集的内标或最高计量要求的元素可能是三重 IDMS 的典型应用。
