ICP-MS Reactive Species Adducts for Isobaric Interference
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Solution Overview
Problem
Current mass spectrometry techniques face challenges in achieving high precision and accuracy due to elemental and molecular interferences, particularly isobaric species, which limit the mass resolving power and sensitivity, especially in cases where high mass resolution is required to separate interfering ions with similar masses.
Innovation Solution
The method involves inducing mass shift reactions within the ICP source to generate mass-shifted ionic molecular species, forming molecular adduct ions with reactive species, which are then filtered and fragmented in a collision cell to eliminate interferences, allowing for interference-free mass analysis of the sample species.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high mass resolution is used to separate interfering ions, then measurement precision is improved, but sensitivity is reduced due to narrow entrance slits
Solution Approach 1:
A collision cell is introduced as an intermediary component between the ion source and mass analyzer. This cell allows ions to undergo collision-induced dissociation or reaction with neutral gas molecules, transforming interfering molecular ions into fragment ions or different mass species that can then be selectively detected, thereby resolving the contradiction between precision and sensitivity
Solution Approach 2:
The patent changes the mass-to-charge ratio parameter of interfering ions through chemical reactions in the collision cell. By reacting interfering molecular ions with neutral gas molecules to produce product ions with different masses, the original mass interference is eliminated while preserving signal intensity, thus improving precision without sacrificing sensitivity
2Measurement precision
If extended chemical sample preparation is applied to remove interferences, then measurement accuracy is improved, but device complexity and time consumption increase
Solution Approach 1:
The patent replaces mechanical/chemical sample preparation steps with a physical-chemical process occurring in the collision cell. Instead of using chemical separation techniques during sample preparation, the interference removal is achieved through gas-phase ion-molecule reactions, thereby simplifying the overall analytical workflow while maintaining high measurement accuracy
Solution Approach 2:
The collision cell performs preliminary interference removal by causing molecular ions to react with neutral gas molecules before they reach the mass analyzer. This preliminary action converts interfering species into detectable product ions, eliminating the need for extensive post-sample-preparation interference management
3Measurement precision
If narrow entrance slits are used to achieve high mass resolution, then measurement precision is improved, but ion transmission is reduced
Solution Approach 1:
The collision cell serves as an intermediary that chemically transforms interfering ions before mass analysis. By converting molecular interferents into fragment ions or product ions with distinct masses through collision-induced reactions, the system achieves effective interference separation without requiring narrow slits, thus maintaining both precision and transmission
Solution Approach 2:
The patent changes the mass parameter of interfering ions through chemical reactions in the collision cell. Interfering molecular ions are converted into product ions with different mass-to-charge ratios, allowing the mass analyzer to distinguish them without requiring high mass resolution, thereby maintaining ion transmission while achieving precise measurements
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the sensitivity and specificity of mass spectrometry by eliminating isobaric interferences, enabling precise analysis of sample species even when high mass resolution is not feasible, thereby improving the accuracy of isotope ratio measurements and reducing the need for extensive sample preparation.
Implementation Method 1
the sample to be analyzed is ionized with an inductively coupled plasma
Implementation Method 2
the sample to be analyzed is ionized with an inductively coupled plasma
Implementation Method 3
at least one molecular adduct ion of the at least one reactive species and the at least one sample species is formed
Implementation Method 4
separated and quantified in a mass analyzer
Data Source
AI summary
Disclosed is a method of inductively coupled plasma mass spectrometry (ICP-MS), comprising steps of introducing at least one sample comprising at least one sample species, and at least one reactive species, into an inductively coupled plasma source, such that at least one molecular adduct ion of the at least one reactive species and the at least one sample species is formed; transferring the at least one molecular adduct ion into a collision cell that is arranged between the inductively coupled plasma source and at least one mass analyzer, transferring the at least one molecular adduct ion, or a product thereof, into the at least one mass analyzer, and analyzing the mass of the at least one molecular adduct ion, or the product thereof, in the at least one mass analyzer. Also disclosed is a mass spectrometer that is adapted to perform the method.