Combining Isotope Dilution and Standard Addition-Elemental Analysis in Complex Samples.

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Materials Science

Background:

• Accurate elemental quantification in complex matrices is crucial for various scientific and industrial applications.
• Existing methods may face challenges with accuracy and robustness when analyzing challenging samples.
• The need for reliable analytical techniques for trace element determination persists.

Purpose of the Study:

• To develop and validate a new analytical method combining isotope dilution mass spectrometry (IDMS) and standard addition.
• To determine the mass fractions of silicon, sulfur, and iron in complex matrices including aqueous TMAH, biodiesel, and human serum.
• To compare the performance and robustness of the developed method against existing approaches.

Main Methods:

• Gravimetric preparation of sample-spike-reference blends for analysis.
• Inductively coupled plasma mass spectrometry (ICP-MS) for isotope ratio measurements.
• Linear regression analysis applied to the measured isotope ratios and blend masses.

Main Results:

• Successfully determined silicon in TMAH, sulfur in biodiesel, and iron in human serum using the novel IDMS method.
• Achieved a relative uncertainty of 90% for silicon blank determination in TMAH, outperforming a related method (150%).
• Demonstrated the robustness and practical applicability of the linear regression-based IDMS approach.

Conclusions:

• The developed IDMS method combined with standard addition provides a robust and accurate approach for elemental analysis.
• The method shows superior performance in terms of uncertainty and applicability for complex matrices.
• This technique offers a valuable tool for precise elemental quantification in diverse scientific fields.