Handling spectral interferences and matrix effects in DRC-ICPMS to assess the elemental profile in human serum samples after dissolution with formic acid

Abstract

Inductively coupled plasma mass spectrometry instrumentation along with the dynamic reaction cell (DRC) technology has been increasingly used in the last decade for multielemental analysis of biological samples. This work reports the development of a method to assess concentrations of Li, Be, B, Sc, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Cd, Sr, Mo, Pd, Ag, Sb, Te, Cs, Ba, Os, Tl, Pb, and Bi in human serum samples treated with formic acid. This is a single-step procedure that minimizes sample handling and avoids contamination risks and analyte losses. Towards this aim, several experimental conditions such as sample pretreatment with formic acid and instrumental operating parameters were optimized. Interferences due to polyatomic ions were eliminated using DRC with oxygen as reaction gas through the formation of MO⁺ ions. Our method involved low dilution factors, and appropriate limits of detection in the low μg L⁻¹ range for all elements. The accuracy was evaluated through the analysis of a standard reference material (Inorganic Constituents in Animal Serum, NIST 1598a) and spiked samples, with satisfactory recoveries.