University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Mass spectrometry

Classification: Mass spectrometry -> time of flight

Citations 4

"Inductively Coupled Plasma Mass Spectrometry For Trace Analysis Using Flow Injection On-line Preconcentration And Time-of-flight Mass Analyser"
Trends Anal. Chem. 2002 Volume 21, Issue 5 Pages 332-342

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Karima Benkhedda, Heidi Goenaga Infante and Freddy C. AdamsElisaveta Ivanova

Abstract: Flow injection (M) methodologies extend the performance of atomic spectroscopic techniques particularly when on-line pre-concentration and separation procedures are involved. This article reviews some of the most relevant aspects of the coupling of FI procedures with inductively coupled plasma-mass spectrometry (ICP-MS), as an attractive approach to perform ultra-trace metal determinations in samples containing a high proportion of total dissolved solids. The capabilities of ICP-time-of-flight (TOF) MS as a fast transient detector for simultaneous determination of a large number of isotopes in a FI peak are also reviewed.
Metals, rare earth Biological Preconcentration Knotted reactor Sequential injection Speciation Review

"Pulsed Sample Introduction Interface For Combining Flow Injection Analysis With Multi-photon-ionization Time-of-flight Mass Spectrometry"
Anal. Chem. 1992 Volume 64, Issue 7 Pages 769-775

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Alan P. L. Wang and Liang Li

Abstract: Sample molecules carried by a liquid carrier (e.g., methanol at 0.5 mL min-1) were vaporized by passage through a heated capillary tube to form aerosol droplets which were entrained in the sample vaporizer of a high-temp. pulsed nozzle. The vapor was injected into the time-of-flight mass spectrometer at a repetition rate determined by the ionization source. The interface described was used to detect both volatile and non-volatile compounds, including those of environmental and biological significance. The average coefficient of variation was 4 to 8%. There were no memory effects or severe peak tailing, and cluster formation during supersonic jet expansion was not a problem. The detection limits for aniline, tryptamine and indole-3-acetic acid were 3, 4 and 140 ng, respectively. The calibration graphs were rectilinear over two-orders of magnitude of analytical range. A pulsed sample introduction (PSI) interface is developed to combine flow injection analysis with a time-of-flight mass spectrometer. In PSI, sample molecules carried by a liquid carrier such as methanol at a flow rate of 0.5 mL/min are vaporized by passing through a heated capillary tube and then through a sample vaporizer of a high-temp. pulsed nozzle. The resulting sample vapors are introduced into the mass spectrometer in a pulsed form and ionized by laser-induced multiphoton ionization. The applicability of this interface for the detection of volatile and nonvolatile compounds is studied. It is found that a variety of chemicals including molecules with environmental or biological significance can be studied by this method. Preliminary studies of the performance of this interface are reported. It is shown that reproducible results from repeated injection of the same concentration. of samples can be readily obtained. The average relative standard deviation is in the range of 4-8%. No memory effects and severe peak tailing are found with this PSI interface. The detection limits of the present technique are compound dependent. For aniline, tryptamine, and indole-3-acetic acid, the detection limits are found to be 3, 140, and 4 ng, respectively. Excellent linearity over two orders of magnitude of analytical range can be obtained for quantitation. It is also shown that cluster formation during the supersonic expansion is not a major problem in this technique.
Methanol Environmental Biological Interface Apparatus Optimization

"Development Of An Ion-trap Linear Time-of-flight Mass-spectrometer With Electrospray-ionization For Microcolumn Liquid-chromatography Detection"
J. Microcolumn Sep. 1995 Volume 7, Issue 6 Pages 603-610

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Randy W. Purves, Liang Li

Abstract: A linear time-of-flight (TOF) mass spectrometer equipped with a quadrupole ion trap for ion storage was developed for mass analysis of ions generated by electrospray ionization (ESI). With this technique, the continuous ion beam from the ESI source is collimated by a set of focusing lenses into the ion trap where the ions are accumulated for a predetermined period of time. Extraction of the ions into the flight tube of the TOF mass spectrometer is achieved by applying a short duration voltage pulse to the exit endcap of the ion trap. The extraction frequency is variable, but is typically set at 10 Hz. It was shown that with a linear TOF mass spectrometer, mass resolution in the range of 600-950 can be routinely obtained. It was also demonstrated that a complete mass spectrum of bradykinin can be obtained with a direct injection of 75 fmol, or 0.5 µL of 150 nM of sample solution. Buffer gas pressure and the energy of the ions entering the ion trap, were found to be the key parameters in obtaining this sensitivity and resolution. In addition, the ESI ion trap/TOF system was developed and applied for microcolumn liquid chromatography detection of a simple protein mixture.
Bradykinin Interface

"Plasma Time-of-flight Mass Spectrometry As A Detector For Short Transient Signals In Elemental Analysis"
Anal. Bioanal. Chem. 2005 Volume 382, Issue 4 Pages 887-890

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Nicolas H. Bings

Abstract: Trace element concentration is becoming increasingly important in many fields, including biomedical, environmental and industrial. Of course, a trace element can often exist in a variety of physico-chemical forms, which exhibit different chemical, toxicological and biological activity. These forms also dictate the bioavailability, distribution and transport of the element in a living organism or in the environment. Many analytical strategies and methods have been described for elemental speciation. The coupling of an efficient separation technique with an element-specific detector is the most common approach.
Silver-107 Barium-138 Indium-116 Magnesium-24 Zinc-68