Gas‐Phase Ion‐Molecule Interactions in a Collision Reaction Cell with ICP‐MS/MS: Investigations with CO₂ as the Reaction Gas

Abstract

Carbon dioxide (CO2) was used as a reaction gas to investigate the gas‐phase ion‐molecule interactions using the Agilent 8900 ICP‐MS/MS. A solution containing forty‐five elements representative of the periodic table was used to supply the ions to react with CO2 in the collision/reaction cell (CRC). The only significant product ions formed were monoxides. The general reactivity was shown to be consistent with density functional theory (DFT)‐predicted reaction enthalpies, such that all predicted exothermic reactions produced product ions at levels of at least 1% of the unreacted ion. Most endothermic reactions observed had sufficient kinetic energy in excess of the reaction enthalpies. Our results suggest that reaction enthalpy is a reasonable predictor of reactivity with CO2 on the timescales of the interactions in non‐thermal ICP‐MS/MS systems. The ease and rapidity of data collection with the ICP‐MS/MS and DFT calculations using the NWChem suite has value given the scarcity of thermochemical data of CO2 reactions in the literature. These studies are especially useful for the identification of targeted reaction chemistries to be leveraged for analytical method development, such as for the inline separation of isobaric interferences from analytes of interest.

Characterisation of gas cell reactions for 70+ elements using N2O for ICP tandem mass spectrometry measurements

“…Conversely, mass-shiing the interference allows the target analyte to be analysed at the same m/z as it enters the cellknown as an "onmass" determination. Other gases used for atom transfer reactions include nitrous oxide (N 2 O), [5][6][7][8] carbon dioxide, 9 sulphur hexauoride, 10 and methyl uoride. 11,12 Asymmetric charge transfer reactions remove interferences by transferring the charge of an interference to the reaction gas (e.g.…”

“…Conversely, mass-shifting the interference allows the target analyte to be analysed at the same m / z as it enters the cell – known as an “on-mass” determination. Other gases used for atom transfer reactions include nitrous oxide (N 2 O), 5–8 carbon dioxide, 9 sulphur hexafluoride, 10 and methyl fluoride. 11,12…”

90Sr bioassay in small-volume urine by ICP-MS/MS with CO2 as the reaction gas

“…Compared to O 2 , the experimental and theoretical investigations on the interactions between CO 2 and atomic metal cations have been few. 26,27 As shown in Fig. 2C, after the reaction between Sr and CO 2 , the four most abundant ions produced were Sr + > SrO + > SrOH + > SrO + (CO 2 ).…”

“…These facts indicated that the reaction of Sr and CO 2 is not energetically favorable, while the reaction of Zr and CO 2 is energetically favorable. 26,27 Furthermore, the additional clusterization with CO 2 to Zr atoms, compared with the sole-oxygen transfer between Zr and O 2 , may have some inuence on the mitigation of the 90 Zr isobaric interference during the measurement of 90 Sr by ICP-MS.…”

Assessing Gas-Phase Ion Reactivity of 50 Elements with NO and the Direct Application for 239Pu in Complex Matrices Using ICP-MS/MS

“…Reactivity scans were conducted mostly as described in previous investigations 5,6,11 V. Two flow rates are used to help determine the effect of increased pressure on product distribution. For this investigation, Q2 was set to the expected products (M + , MN + , MO + , MNO + , MO 2 +…”