The goal of this study was to evaluate the uncertainty of elemental analytical methods that use laser ablation in liquid (LAL) as a pretreatment. After LAL sampling of silicon carbide (SiC), trace impurities were quantified using inductively coupled plasma-sector field mass spectrometry (ICP-SFMS) with external calibration (EC). The expanded uncertainty (k = 2) of the concentrations was less than 10 %. To obtain more precise values, the Ti, the element homogeneously distributed on the sample surface of SiC, was quantified using ICP-SFMS with isotope dilution mass spectrometry (IDMS). The expanded uncertainty (k = 2) was reduced to 3.4 %. The smaller uncertainty associated with IDMS reflected the fact that measuring the isotope ratio of the same element with IDMS and high-speed isotope measurements at 10-ms intervals reduced the variability of signal intensities, the primary source of uncertainty, more effectively than EC. Moreover, the combination with ID improved the sample amount-dependent unrepeatability in pretreatment.
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