Determination of Trace Metal (Mn, Fe, Ni, Cu, Zn, Co, Cd and Pb) Concentrations in Seawater Using Single Quadrupole ICP-MS: A Comparison between Offline and Online Preconcentration Setups

The quantification of dissolved metals in seawater requires pre-treatment before the measurement can be done, posing a risk of contamination, and requiring a time-consuming procedure. Despite the development of automated preconcentration units and sophisticated instruments, the entire process often introduces inaccuracies in quantification, especially for low-metal seawaters. This study presents a robust method for measuring dissolved metals from seawater accurately and precisely using a seaFAST and quadrupole Inductively Coupled Plasma Mass Spectrometer (ICPMS), employed in both offline (2016–2018) and online (2020–2021) setups. The proposed method shows data processing, including the re-calculation of metals after eliminating the instrumental signals caused by polyatomic interferences. Here, we report the blank concentration of Fe below 0.02 nmol kg−1, somewhat lower values than that have been previously reported using high-resolution and triple-quad ICPMS. The method allows for the accurate determination of Cd and Fe concentrations in low-metal seawaters, such as GEOTRACES GSP, using a cost-effective quadrupole ICPMS (Cdconsensus: 2 ± 2 pmol kg−1, Cdmeasured: 0.99 ± 0.35 pmol kg−1; Feconsensus: 0.16 ± 0.05 nmol kg−1, Femeasured: 0.21 ± 0.03 nmol kg−1). Between two setups, online yields marginally lower blank values for metals based on short-term analysis. However, the limit of detection is comparable between the two, supporting optimal instrumental sensitivity of the ICPMS over 4+ years of analysis.

Gadolinium-based contrast agents: A clinically significant analytical interference in inductively coupled plasma mass spectrometry elemental analysis

Background Gadolinium-based contrast agents (GBCAs) have been used in magnetic resonance imaging for the past 30 years, where they have significantly improved the effectiveness of imaging studies. However, the increased usage of gadolinium in the medical community has also resulted in unexpected interferences in other laboratory assays. This has been particularly the case in clinical elemental analysis using inductively coupled plasma mass spectrometry (ICP-MS). Methods By conducting ICP-MS interference experiments, we describe how gadolinium interferes with elemental analysis by space charge effect, double charge effect and the creation of polyatomic interferences. Additionally, by reviewing more than a year of reference laboratory data from our laboratory information system, we determined the number of elemental tests cancelled due to gadolinium interference. Results Interference experiments show that gadolinium normally found in GBCAs can interfere with heavy metals, platinum and selenium analysis of biological fluids using ICP-MS. Within one year, our institution’s metals laboratory had to cancel 42 selenium serum tests and 19 heavy metal urine panels due to potential interference caused by gadolinium. Conclusions GBCAs will continue to be utilized in hospitals around the world. However, clinical laboratories should be wary of potential interferences caused by GBCAs. Relevant interferences include space charge effect, double charge interference, and the formation of polyatomic interferences caused by gadolinium. These interferences can negatively affect patient care by resulting in cancelled laboratory tests and causing patients to have blood redrawn and analysed at a later date leading to delays in their diagnosis/treatment.

Method for quantifying and removing polyatomic interferences on a suite of moderately volatile elements (Zn, Se, Rb, Ag, Cd, In, Sb, Tl, Pb, and Bi) during solution-mode ICP-MS

Moderately volatile elements (MVEs: Zn, Se, Rb, Ag, Cd, In, Sb, Tl, Pb, and Bi) have condensation temperatures between 650 and 1250 K.

Characterisation of matrix-based polyatomic interference formation in laser ablation-inductively coupled plasma-mass spectrometry using dried micro-droplet ablation and its relevance for bioimaging

Dried micro-droplets were used to characterise the formation of polyatomic interferences by LA-ICP-MS.