Explore the feasibility of electrospray ionization high-resolution mass spectrometry in elemental analysis

As a representative soft ionization technique, electrospray ionization (ESI) is commonly applied for the analysis of organic and biological compounds and is less used in inorganic applications. This study introduces the performance of ESI high-resolution mass spectrometry (HRMS) in the detection of elements. The HRMS instrument was equipped with a sub-atmospheric pressure (SAP) ESI source to reduce sample consumption and simplify the sampling operations. In addition, in-source collision-induced dissociation (IS-CID) was introduced into the analysis to generate simple metallic ion species such as atomic ions and charged oxides and reduce organic peak interferences. Various solutions containing metal salts and organometallic compounds were analyzed, demonstrating a picogram-level absolute detection limit and accurate multi-element identification capability of the instrument. Furthermore, SAP-ESI-HRMS exhibits diverse analytical performances, enabling both elemental and organic analyses by simply regulating the IS-CID energy in the measurement.