A multisample, high‐intensity Cs sputter negative ion source for accelerator mass spectrometry applications

1992 ◽  
Vol 63 (4) ◽  
pp. 2472-2474 ◽  
Author(s):  
Si Houzhi ◽  
Zhang Weizhong ◽  
Zhu Jinhua ◽  
Du Guangtian ◽  
Zhang Tiaorong
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
High Intensity ◽  
Ion Source ◽  
Negative Ion

scholarly journals Fabrication of silicon‐based optical components for an ultraclean accelerator mass spectrometry negative ion source

1994 ◽  
Vol 65 (5) ◽  
pp. 1570-1574 ◽  
Author(s):  
J. F. Kirchhoff ◽  
D. K. Marble ◽  
D. L. Weathers ◽  
F. D. McDaniel ◽  
S. Matteson ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Ion Source ◽  
Negative Ion ◽  
Optical Components ◽  
Silicon Based

The properties of high‐intensity heavy‐negative‐ion source, NIABNIS

1990 ◽  
Vol 61 (1) ◽  
pp. 427-429 ◽  
Author(s):  
Hiroshi Tsuji ◽  
Junzo Ishikawa ◽  
Takeshi Maekawa ◽  
Toshinori Takagi
Keyword(s):  
High Intensity ◽  
Ion Source ◽  
Negative Ion

scholarly journals Simultaneous Quantification of Six Bioactive Components in Decoction of Ziziphi spinosae Semen Using Ultrahigh Performance Liquid Chromatography Coupled with Triple-Quadrupole Mass Spectrometry

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Xiao Liu ◽  
Xiaochai Zhu ◽  
Hui Zhu ◽  
Li Xie ◽  
Jia Ma ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Betulinic Acid ◽  
Ion Source ◽  
Negative Ion ◽  
Phase System ◽  
Triple Quadrupole ◽  
Bioactive Components ◽  
Simultaneous Quantification ◽  
Ultrahigh Performance Liquid Chromatography

This paper was conducted to develop a method containing ultrahigh performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry for simultaneous quantification of six bioactive components in the decoction of Ziziphi spinosae Semen. Analysis was performed on an Agilent ZORBAX Extend-C18 column (2.1 × 100 mm, 1.8 μm) and eluted with a mobile phase system consisting of acetonitrile and water under a gradient program with a flow rate of 0.3 ml/min. The injection volume was 2 μl. Multiple-reaction monitoring scanning detection was employed for quantification with an electrospray ion source in the negative ion mode. All the six compounds showed good linearities (r≥0.9996). The LODs of the six bioactive compounds were 0.039 ng/ml, 0.092 ng/ml, 3.112 ng/ml, 2.131 ng/ml, 0.099 ng/ml, and 0.071 ng/ml for spinosin, 6‴-feruloylspinosin, jujuboside A, jujuboside B, camelliaside B, and betulinic acid, respectively. The LOQs were 0.118 ng/ml, 0.276 ng/ml, 9.336 ng/ml, 6.393 ng/ml, 0.299 ng/ml, and 0.213 ng/ml for spinosin, 6‴-feruloylspinosin, jujuboside A, jujuboside B, camelliaside B, and betulinic acid, respectively. According to our knowledge, it was the first time to establish a method with high efficiency and accuracy for the quantification of six bioactive components in the decoction of Ziziphi spinosae Semen, which would provide references for quality control and evaluation of Ziziphi spinosae Semen.

A microbeam Cs ion source for accelerator mass spectrometry

1998 ◽  
Vol 69 (3) ◽  
pp. 1353-1358 ◽  
Author(s):  
S. H. Sie ◽  
T. R. Niklaus ◽  
G. F. Suter ◽  
F. Bruhn
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Ion Source

scholarly journals Radiocarbon with Gas Chromatography

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 711-716 ◽  
Author(s):  
Christopher Bronk Ramsey ◽  
R. E. M. Hedges
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Pilot Study ◽  
Accelerator Mass Spectrometry ◽  
Ion Source ◽  
Tracer Studies ◽  
Chemical Fractions ◽  
Peak Sensitivity ◽  
Accelerator System

In 14C tracer studies, and when looking for modern contamination in archaeological samples, it is often necessary to measure the 14C concentration of individual chemical fractions. Gas chromatography (GC) is one method that is frequently used for separation of chemical fractions. The gas ion source at the Oxford Radiocarbon Accelerator Unit for accelerator mass spectrometry (AMS) provides the opportunity to measure fractions from a GC instrument directly. Although the first investigations are likely to be 14C tracer studies, such a GC-AMS system could find much wider application. We present results from a pilot study of the peak sensitivity, baseline stability and crosstalk of the accelerator system used in this way. We also discuss the practical considerations in developing a GC-AMS instrument for routine use.

Fast Atom Bombardment Mass Spectra of Some N-α-(t-Butoxycarbonyl)-O-(diorganylphosphono)-L-serines and O-(Diorganylphosphono)seryl-Containing Dipeptides and Tripeptides

1994 ◽  
Vol 47 (2) ◽  
pp. 229 ◽  
Author(s):  
JW Perich ◽  
I Liepa ◽  
AL Chaffee ◽  
RB Johns
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrum ◽  
High Intensity ◽  
Mass Spectra ◽  
Fast Atom Bombardment ◽  
Molecular Ions ◽  
Operating Conditions ◽  
Negative Ion ◽  
The Matrix ◽  
Positive Ion

Positive and negative ion fast atom bombardment ( f.a.b .) mass spectrometry were found to be useful methods for the analysis and structural characterization of five Nα-(t- butoxycarbonyl )-O-( diorganylphosphono )-L- serines ( organyl = Ph, Et, Me, Bzl , But), especially in the case of the sensitive benzyl and t-butyl phosphono derivatives. Under positive ion operating conditions, high intensity pseudo-molecular ions were obtained in the f.a.b . mass spectra, and the fragmentation pathway of the phenyl, ethyl and methyl derivatives was established by parent/daughter linked scanning studies to involve (a) the two-step loss of the t- butoxycarbonyl group, (b) loss of the amino acid as the neutral fragment from the [MH]+, [MH-56]+, [MH-100]+ and [MH-146]+ ions by a four- centred β-elimination rearrangement, and (c) cleavage of the phosphono phenyl and ethyl groups from only the [(RO)2P(OH)2]+ and [NH=CHCH2PO3R2+H]+ fragments. Parent/daughter linked scanning studies of the benzyl derivative showed that the prominent fragmentation involved loss of the benzyl group as the tropylium ion and that the 'apparent' [MH-90]+ peak observed in its f.a.b. mass spectrum resulted from cleavage of the phosphono benzyl group in the matrix during the bombardment process. In the case of the t-butyl derivative, parent/daughter linked scanning studies showed that the prominent fragmentation involved successive 'in-flight' loss of the phosphono t-butyl groups as isobutene. Negative ion f.a.b. mass spectrometry of the five derivatives gave f.a.b. mass spectra which displayed distinct [M-H]- anions along with high intensity [M-H-R]- and [(RO)2PO2]- fragment anions, the f.a.b . mass spectrum of the t-butyl derivative containing an additional [M-H-But-But]- fragment anion. Parent/daughter linked scanning studies established that the majority of the observed fragment anions resulted from extensive fragmentation of the Boc -Ser(PO3R2)-OH derivatives in the matrix phase followed by sputtering of the resultant fragments into the gas phase. In addition, positive ion f.a.b . mass spectrometry was found to be useful for the analysis of a series of protected O-( diorganylphosphono ) seryl-containing dipeptides and tripeptides ( organyl = Ph, Et, Me, Bzl ). The obtained spectra showed that β-elimination fragmentation of the Ser(PO3R2) residue was more pronounced with the tripeptide series and indicated that there was increased sensitivity of the O-( diorganylphosphono ) seryl residue with replacement of the Boc group by an amino acyl residue at its N-terminus.

scholarly journals Optimizing a microwave gas ion source for continuous-flow accelerator mass spectrometry

2012 ◽  
Vol 83 (2) ◽  
pp. 02B304 ◽  
Author(s):  
K. F. von Reden ◽  
M. L. Roberts ◽  
J. R. Burton ◽  
S. R. Beaupré
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Continuous Flow ◽  
Ion Source
Sign in / Sign up

Export Citation Format

Share Document