Inductively Coupled Plasma Mass Spectrometry Performance for the Measurement of Key Serum Minerals: A Comparative...

Inductively coupled plasma mass spectrometry (ICP-MS) is widely used for the accurate measurement of minerals. However, its application to serum essential mineral measurement has not been fully evaluated. The present study aimed to assess the performance of ICP-MS for serum minerals by comparing its measurements to those obtained using standard quantification methods.

Cross-sectional data were collected from 282 participants from a single facility in Japan. Serum concentrations of eight key minerals, namely sodium, potassium, calcium, phosphorus, magnesium, iron, zinc, and copper, measured via ICP-MS and standard methods were compared using Passing-Bablok regression and Bland-Altman plots.

All minerals, except phosphorus, exhibited good agreement with standard methods, with more stable regression coefficients observed for minerals with greater interindividual variability. After systematically filtering outliers, the mean relative errors were approximately -3% for sodium, potassium, calcium, and magnesium; +5% for iron; 0% for zinc; and -19% for copper. The outliers for iron were primarily due to mild hemolysis, whereas those for zinc were largely attributed to nonhemolysis factors. For phosphorus, the serum total phosphorus concentration measured using ICP-MS was approximately 3.5 times higher than the serum inorganic phosphorus concentration measured using standard methods, with a weak correlation observed between the two methods.

This study provides a practical foundation for future research. Understanding ICP-MS characteristics will facilitate the development of new approaches in clinical diagnostics.