Experimental measurements of quadrupole mass analyser performance and comparison with theoretical predictions

Dawson, Peter

doi:10.1016/0020-7381(76)80130-1

Cited by 24 publications

(11 citation statements)

References 12 publications

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“…Ion transmission has been improved by the use of a larger orifice supported by a triple‐stage turbo pump 16. And, finally, the hyperbolic quadrupole rods and the accompanying radio‐frequency (RF) circuitry have been redesigned, which allows the user to obtain enhanced mass resolution with only a small loss in signal intensity 17, 18. Namely, resolution of a quadrupole mass filter is proportional to the number of RF cycles an ion experiences while traversing the quadrupole rods that, in turn, is related to the RF frequency and the length of the quadrupole rods.…”

Section: Resultsmentioning

confidence: 99%

Benzoannelatedcis,cis,cis,trans-[5.5.5.6]Fenestranes: Syntheses, Base Lability, and Flattened Molecular Structure of Strained Epimers of the all-cis Series

2001

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Tribenzofenestranes possessing the strained cis,cis,cis,trans-[5.5.5.6]-fenestrane skeleton have been synthesized from cis-2,6-diphenylspiro[cyclohexane-1,2'-indane]-1',3'-diols by two-fold cyclodehydration, in striking analogy to the strategy used previously to construct the stereoisomeric all-cis-tribenzo[5.5.5.6]fenestranes from the corresponding trans-diphenylspirodiols. In this manner, both of the parent hydrocarbons, all-cis-tribenzo[5.5.5.6]fenestrane 3 and cis,cis,cis,trans-tribenzo[5.5.5.6]fenestrane 4, have been made accessible from the spirodiketones 5 and 6, respectively. The C6-functionalized derivatives of 4-cis,cis,cis,trans-fenestranol 9 and cis,cis,cis,trans-fenestranone 12-were prepared through cis-diphenylspirotriol 8 and cis-diphenyldispiroacetaldiol 11, by using the same strategy. The cis,cis,cis,trans-[5.5.5.6]fenestrane framework readily epimerizes to the more stable all-cis isomers under basic conditions, but is stable under neutral or acidic conditions. For example, cis,cis,cis,trans-fenestranone 12 yielded all-cis fenestrane 3 under Wolff-Kishner conditions, but cis,cis,cis,trans-isomer 4 under Clemmensen conditions. Epimerization was also circumvented by radical-induced desulfurization of fenestrane dithiolane 15 with nBu3SnH/AIBN, producing 4 in excellent yields. A single-crystal X-ray structure analysis of 4 revealed that, in accordance with force field and semi-empirical MO calculations, the extra strain of the benzoannelated cis,cis,cis,trans-[5.5.5.6]fenestratriene framework [Estrain(4)-Estrain(3)=46 kJmol(-1)] is due both to the almost perfect boat conformation of the six-membered ring and to considerable bond angle widening at the central, non-bridged C4b-C15d-C11b unit (121 degrees). H/D exchange experiments with the cis,cis,cis,trans hydrocarbon 4 under basic conditions demonstrated that the strain-induced epimerization to 3 occurs through direct deprotonation of the "epimeric" benzylic bridgehead C7a-H bond, which was found to be more acidic than the two C-H bonds at the benzhydrylic bridgeheads.

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Section: Resultsmentioning

confidence: 99%

Benzoannelatedcis,cis,cis,trans-[5.5.5.6]Fenestranes: Syntheses, Base Lability, and Flattened Molecular Structure of Strained Epimers of the all-cis Series

2001

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“…The improved sensitivity may be attributed to several advancements in the TSQ Quantum Ultra instrument 16, 18. Namely, ionization efficiency has been improved by the advanced design of a new orthogonal ion source.…”

Section: Resultsmentioning

confidence: 99%

Enhanced resolution triple‐quadrupole mass spectrometry for ultra‐sensitive and quantitative analysis of the investigational anticancer agent EO9 (apaziquone) and its metabolite EO5a in human and dog plasma to support (pre)‐clinical studies of EOquin® given intravesically

Vainchtein

Rosing

Mirejovsky

et al. 2008

Rapid Comm Mass Spectrometry

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A highly sensitive and selective liquid chromatography/tandem mass spectrometric (LC/MS/MS) method was developed to quantify the experimental anticancer agent EO9 and its metabolite EO5a in biological matrices. A 200-microL aliquot of human/dog plasma was spiked with a mixture of deuterated internal standards EO9-d3 and EO5a-d4 and extracted with 1.25 mL of ethyl acetate. Dried extracts were reconstituted in 0.1 M ammonium acetate/methanol (7:3, v/v) and 20-microL volumes were injected onto the LC system. Separation was achieved on a 150 x 2.1 mm C18 column using an alkaline eluent (1 mM ammonium hydroxide/methanol (gradient system)). The detection was performed by a Finnigan TSQ Quantum Ultra equipped with an electrospray ionization source operated in positive mode and enhanced mass resolution capability. It demonstrated improved sensitivity with a factor 10-20 for EO9 and EO5a over a 3-decades dynamic range, with acceptable accuracy and precision, when compared with the previously described assay for EO9 and EO5a, developed by our group, using an API 2000. The assay quantifies a range from 0.5 to 500 ng/mL for EO9 and EO5a using 200-microL human plasma and dog samples. The described mass resolution method was successfully applied for the evaluation of the pharmacokinetic profile of EO9 and its metabolite EO5a in human and dog plasma.

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“…In this section, the peaks will tend to be triangular in shape. In fact transmission decreases approximately with the square of the resolution (24,25). The main contribution to the width of the peak is the transmission of ions with stable trajectories.…”

Section: The Real World: Performance Measurementsmentioning

confidence: 96%

“…In cases where the ion source gives ions of a well-defined energy which are emitted fairly uniformly in phase space, a typical result (24) is that shown in Fig. 3.…”

Section: The Real World: Performance Measurementsmentioning

confidence: 97%

“…Calculations have shown that it is the total time the ions spend in the fringing field which is significant rather than the final ion velocity. However, on the basis of some experimental observations, it was suggested that the retarded ion entry tends to increase the value of h, thus limiting attainable resolution (24). More measurements are required.…”

Section: Fringing Fieldsmentioning

confidence: 98%

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Quadrupole mass analyzers: Performance, design and some recent applications

Dawson

1986

Mass Spectrometry Reviews

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Experimental measurements of quadrupole mass analyser performance and comparison with theoretical predictions

Cited by 24 publications

References 12 publications

Benzoannelatedcis,cis,cis,trans-[5.5.5.6]Fenestranes: Syntheses, Base Lability, and Flattened Molecular Structure of Strained Epimers of the all-cis Series

Benzoannelatedcis,cis,cis,trans-[5.5.5.6]Fenestranes: Syntheses, Base Lability, and Flattened Molecular Structure of Strained Epimers of the all-cis Series

Enhanced resolution triple‐quadrupole mass spectrometry for ultra‐sensitive and quantitative analysis of the investigational anticancer agent EO9 (apaziquone) and its metabolite EO5a in human and dog plasma to support (pre)‐clinical studies of EOquin® given intravesically

Quadrupole mass analyzers: Performance, design and some recent applications

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