Simultaneous multi-element determination in whole blood and urine via dual-mode ICP-MS

The content of elements in the body has a significant relationship with human health. However, the wide variation in the concentrations of different elements in blood or urine poses challenges for accurate detection. This study presents a dual-mode ICP-MS methodology integrating kinetic energy discrimination (KED) and dynamic reaction cell (DRC) technologies, specifically designed to address the analytical challenge of quantifying 22 physiologically critical elements (Be, V, Cr, Mn, Fe, Ca, Mg, Ba, Co, Cd, Cu, Zn, As, Se, Ti, Sr, Ni, Mo, Sn, Sb, Tl, Pb) spanning six orders of magnitude in concentration (μg/L to g/L) within complex biological matrices. Rejection parameter q (RPq) adjusts the low-mass cutoff, while rejection parameter a (RPa) controls the high-mass cutoff. Optimizing both extends the low-interference dynamic range. The method's core innovation lies in the synchronized optimization of quadrupole parameters RPa and RPq, which enables simultaneous suppression of matrix-derived polyatomic interferences while maintaining linear detector response across ultra-wide dynamic ranges. The method employs a dual-mode analysis approach: (1) In urine analysis, the KED-He mode is suitable for analyzing all elements. (2) In whole blood analysis, DRC-NH₃ mode is used for interference-prone elements (Mn, Cr, Ca), and KED-He mode is used for the remaining elements. Strategic optimization of quadrupole rejection parameters (RPa/RPq) achieved intra-day precision of 0.5-7.2 % (blood) and 1.6-5.5 % (urine), with inter-day variations ≤9.6 %, demonstrating robust performance for multi-element profiling across clinically relevant concentration ranges.