Title: Brubaker lens
Long Title: IUPAC Gold Book - Brubaker lens
DOI: 10.1351/goldbook.12349
Status: current

Definition
Additional set of four short, cylindrical electrodes, mounted co-linearly with a transmission quadrupole mass spectrometer that is excited with some fraction of the AC potential but not the DC potential applied to the main quadrupole. The Brubaker lens thus acts as a high-pass filter for ion m/z, but the resulting delay in application of the DC potential component also results in a reduction in defocusing by fringe fields and thus significantly improves overall ion transmission efficiency at a given mass resolution.

Related Terms
- fringe fields: https://goldbook.iupac.org//terms/view/12420
- transmission efficiency: https://goldbook.iupac.org//terms/view/12601
- transmission quadrupole mass spectrometer: https://goldbook.iupac.org//terms/view/12602

Source
- PAC, 2013, 85, 1515. 'Definitions of terms relating to mass spectrometry (IUPAC Recommendations 2013)' on page 1526 (https://doi.org/10.1351/PAC-REC-06-04-06)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/12349/html
- json: https://goldbook.iupac.org/terms/view/12349/json
- xml: https://goldbook.iupac.org/terms/view/12349/xml

Citation: Citation: 'Brubaker lens' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.12349
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Accessed: 2026-05-08T04:48:39+00:00