Comprehensive Study Shows Versatility of N2O Gas for ICP-MS Measurements
A new study conducted by Shaun T. Lancaster from Montanuniversität Leoben in Austria and the University of Calgary in Canada demonstrates the high versatility of nitrous oxide (N2O) as a reaction cell gas for routine inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) measurements. The study, published in the Journal of Analytical Atomic Spectrometry, characterizes gas cell reactions for 73 elements using N2O, with a comparison to the most widely used mass-shift method using oxygen (O2) as a reaction gas (1). Out of the 73 elements, 59 showed improved sensitivity when performing mass-shift with N2O compared to O2, with 8 elements showing no reaction with either gas. Additionally, N2O demonstrated a collisional focusing effect for 36 elements when measuring on-mass. This effect was not observed using O2.
Nitrous oxide cylinder vector icon isolated on white background. | Image Credit: © Adam - stock.adobe.com
N2O is a highly reactive gas that is useful for ICP-MS/MS analysis. It is typically used as a reaction cell gas to reduce spectral interferences. N2O can be used to mass-shift target analytes to a higher mass-to-charge (m/z) ratio with increased sensitivity, which improves the detection limits of trace elements. Additionally, N2O can be used to monitor asymmetric charge transfer reactions, which highlights the potential of some elements to become metastable ions that could be used as an alternative mass-shift option. The use of N2O in ICP-MS/MS analysis has gained more traction in recent years because of its versatility and the growing number of publications that have used it. Overall, N2O is a valuable tool for routine ICP-MS/MS measurements.
The study highlights the usefulness of N2O as a highly reactive gas, typically used for mass-shifting only target analytes to a higher mass-to-charge ratio with increased sensitivity. The traditional use of N2O was limited to selected applications because of the creation of new interferences that also interfere with the detected masses of interest. However, with the advent of ICP-MS/MS, the use of N2O has gained more traction, with a growing number of publications in recent years.
Moreover, monitoring asymmetric charge transfer reactions with N2O highlighted 14 elements, primarily non-metals and semi-metals, that enter the gas cell as metastable ions and could be used as an alternative mass-shift option. Overall, the results from this comprehensive study suggest that N2O is a highly versatile reaction cell gas for routine ICP-MS/MS measurements and can significantly improve sensitivity and accuracy of spectral interferences in a wide range of applications.
Reference
(1) Lancaster, S. T.; Prohaska, T.; Irrgeher, J. Characterisation of gas cell reactions for 70+ elements using N2O for ICP tandem mass spectrometry measurements. J. Anal. At. Spectrom. 2023, ASAP. DOI: 10.1039/D3JA00025G
Inside the Laboratory – The Petrochronology Group at University of California, Santa Barbara
January 29th 2024In this edition of “Inside the Laboratory,” John Cottle, PhD, a professor of geology at the University of California, Santa Barbara, and a member of Spectroscopy’s Editorial Advisory Board, discusses his group’s most recent work using “laser ablation split steam” analysis to measure elemental concentrations and isotopic ratios in rocks and minerals.
