Brauckmann Christine, Pramann Axel, Rienitz Olaf, Schulze Alexander, Phukphatthanachai Pranee, Vogl Jochen
Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany.
Bundesanstalt für Materialforschung und-prüfung (BAM), Richard-Willstätter-Str.11, 12489 Berlin, Germany.
Molecules. 2021 Apr 30;26(9):2649. doi: 10.3390/molecules26092649.
A new method combining isotope dilution mass spectrometry (IDMS) and standard addition has been developed to determine the mass fractions of different elements in complex matrices: (a) silicon in aqueous tetramethylammonium hydroxide (TMAH), (b) sulfur in biodiesel fuel, and (c) iron bound to transferrin in human serum. All measurements were carried out using inductively coupled plasma mass spectrometry (ICP-MS). The method requires the gravimetric preparation of several blends (b)-each consisting of roughly the same masses () of the sample solution (x) and of a spike solution (y) plus different masses () of a reference solution (z). Only these masses and the isotope ratios () in the blends and reference and spike solutions have to be measured. The derivation of the underlying equations based on linear regression is presented and compared to a related concept reported by Pagliano and Meija. The uncertainties achievable, e.g., in the case of the Si blank in extremely pure TMAH of ((Si)) = 90% (linear regression method, this work) and ((Si)) = 150% (the method reported by Pagliano and Meija) seem to suggest better applicability of the new method in practical use due to the higher robustness of regression analysis.
一种结合同位素稀释质谱法（IDMS）和标准加入法的新方法已被开发出来，用于测定复杂基质中不同元素的质量分数：（a）氢氧化四甲铵（TMAH）水溶液中的硅，（b）生物柴油燃料中的硫，以及（c）人血清中与转铁蛋白结合的铁。所有测量均使用电感耦合等离子体质谱法（ICP-MS）进行。该方法需要通过重量法制备几种混合溶液（b）——每种混合溶液大致由相同质量（）的样品溶液（x）和加标溶液（y）以及不同质量（）的参考溶液（z）组成。只需测量这些混合溶液以及参考溶液和加标溶液中的这些质量和同位素比（）。本文给出了基于线性回归的基础方程的推导，并与Pagliano和Meija报道的相关概念进行了比较。例如，在极纯TMAH中硅空白的情况下，通过本工作的线性回归法可实现的不确定度为（（Si）） = 90%，而Pagliano和Meija报道的方法为（（Si）） = 150%，由于回归分析具有更高的稳健性，这似乎表明新方法在实际应用中具有更好的适用性。
