Quadrupole mass analyzers: Performance, design and some recent applications

Dawson, Peter

doi:10.1002/mas.1280050102

Cited by 83 publications

(51 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Generally, the PW model is considered to be valid for q<0. 4. The extended applicable range of q by using the PW model has also been found in the study of potential well depth [66].…”

Section: Resultsmentioning

confidence: 65%

A Theoretical Method for Characterizing Nonlinear Effects in Paul Traps with Added Octopole Field

Xiong

Zhou

Zhang

et al. 2015

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Abstract. In comparison with numerical methods, theoretical characterizations of ion motion in the nonlinear Paul traps always suffer from low accuracy and little applicability. To overcome the difficulties, the theoretical harmonic balance (HB) method was developed, and was validated by the numerical fourth-order Runge-Kutta (4th RK) method. Using the HB method, analytical ion trajectory and ion motion frequency in the superimposed octopole field, ε, were obtained by solving the nonlinear Mathieu equation (NME). The obtained accuracy of the HB method was comparable with that of the 4th RK method at the Mathieu parameter, q=0.6, and the applicable q values could be extended to the entire first stability region with satisfactory accuracy. Two sorts of nonlinear effects of ion motion were studied, including ion frequency shift, Δβ, and ion amplitude variation, Δ(C 2n /C 0 ) (n≠0). New phenomena regarding Δβ were observed, although extensive studies have been performed based on the pseudo-potential well (PW) model. For instance, the |Δβ| at ε=0.1 and ε=-0.1 were found to be different, but they were the same in the PW model. This is the first time the nonlinear effects regarding Δ(C 2n /C 0 ) (n≠0) are studied, and the associated study has been a challenge for both theoretical and numerical methods. The nonlinear effects of Δ(C 2n /C 0 ) (n≠0) and Δβ were found to share some similarities at q<0.6: both of them were proportional to ε, and the square of the initial ion displacement, z(0) 2 .

show abstract

“…Generally, the PW model is considered to be valid for q<0. 4. The extended applicable range of q by using the PW model has also been found in the study of potential well depth [66].…”

Section: Resultsmentioning

confidence: 65%

A Theoretical Method for Characterizing Nonlinear Effects in Paul Traps with Added Octopole Field

Xiong

Zhou

Zhang

et al. 2015

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

show abstract

“…To operate the trap, an electric voltage, Φ 0 = U − Vcos(Ωt), is applied between the ring and the endcap electrodes [2,3]. Herein, U is the direct-current (DC) voltage, V is the radio-frequency (rf) voltage with angular frequency Ω, and t is time.…”

Section: Theorymentioning

confidence: 99%

“…The ideal Paul trap should produce a linear quadrupole electric field. However, the electric field in the real trap always contains nonlinear higher-order field components, such as hexapole and octopole [2,3]. Using the octopole field as an example, its typical weight regarding the field strength is ca.…”

Section: Introductionmentioning

confidence: 99%

“…They not only change the frequencies and amplitudes of the natural harmonics but also produce nonlinear harmonics (marked in red) superimposed into the natural harmonics of ion motion [17,18]. Generally, among the harmonics, the ion fundamental secular oscillation has the largest amplitude and is therefore the most important [2,3]. By neglecting all the other smallamplitude harmonics, including higher-frequency and nonlinear ones, theoretical methods, such as the most often employed pseudo-potential well (PW) model [19,20], can focus on the nonlinear effects of ion secular motion [10,[21][22][23][24][25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nonlinear Ion Harmonics in the Paul Trap with Added Octopole Field: Theoretical Characterization and New Insight into Nonlinear Resonance Effect

Xiong

Zhou

Zhang

et al. 2015

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Abstract. The nonlinear harmonics within the ion motion are the fingerprint of the nonlinear fields. They are exclusively introduced by these nonlinear fields and are responsible to some specific nonlinear effects such as nonlinear resonance effect. In this article, the ion motion in the quadrupole field with a weak superimposed octopole component, described by the nonlinear Mathieu equation (NME), was studied by using the analytical harmonic balance (HB) method. Good accuracy of the HB method, which was comparable with that of the numerical fourth-order Runge-Kutta (4th RK), was achieved in the entire first stability region, except for the points at the stability boundary (i.e., β = 1) and at the nonlinear resonance condition (i.e., β = 0.5). Using the HB method, the nonlinear 3β harmonic series introduced by the octopole component and the resultant nonlinear resonance effect were characterized. At nonlinear resonance, obvious resonant peaks were observed in the nonlinear 3β series of ion motion, but were not found in the natural harmonics. In addition, both resonant excitation and absorption peaks could be observed, simultaneously. These are two unique features of the nonlinear resonance, distinguishing it from the normal resonance. Finally, an approximation equation was given to describe the corresponding working parameter, q nr , at nonlinear resonance. This equation can help avoid the sensitivity degradation due to the operation of ion traps at the nonlinear resonance condition.

show abstract

“…Its operation is well-understood [2][3][4]. The device consists of a set of four parallel electrodes, arranged to create a hyperbolic electrostatic field as shown in Figure 1a.…”

Section: Introductionmentioning

confidence: 99%

Microfabricated Quadrupole Mass Spectrometer With a Brubaker Prefilter

Wright¹,

O'Prey²,

Syms

et al. 2010

J. Microelectromech. Syst.

View full text Add to dashboard Cite

Microfabricated quadrupole mass spectrometers with Brubaker pre-filters are demonstrated for the first time. Complete filters are assembled from two dies, each carrying two pairs of rods providing the pre-filter and main filter sections. The rods are held in precision silicon mounts that are fabricated using wafer scale deep reactive ion etching and anodic bonding to glass substrates. Improvements to ion transmission are obtained by tuning the bias potential applied to the pre-filter. The effect is explained in terms of a simple analytic theory for ion motion in the pre-filter. Mass filtering with a range of m/z = 0-1200 and a resolution of m/Δm ≈ 150 at 10% of peak height is demonstrated using 2-4 mm long pre-filter electrodes, 30 mm long main electrodes (both of 650 µm diameter) and a RF drive at ≈ 6.5 MHz.

show abstract

Quadrupole mass analyzers: Performance, design and some recent applications

Cited by 83 publications

References 58 publications

A Theoretical Method for Characterizing Nonlinear Effects in Paul Traps with Added Octopole Field

A Theoretical Method for Characterizing Nonlinear Effects in Paul Traps with Added Octopole Field

Nonlinear Ion Harmonics in the Paul Trap with Added Octopole Field: Theoretical Characterization and New Insight into Nonlinear Resonance Effect

Microfabricated Quadrupole Mass Spectrometer With a Brubaker Prefilter

Contact Info

Product

Resources

About