Dean B. Atkinson - Research Notes
Assistant Professor of Chemistry
-Ph.D., 1995, University of Arizona
-National Research Council Postdoctoral Fellowship, National Institute
of Standards and Technology, 1995-1997
Analytical/Physical Chemistry; Atmospheric Chemistry and Physics;
Society of Chemistry journal The Analyst has recently published my
review of environmental science applications of Cavity Ring-Down (CRD)
spectroscopy. This Tutorial Review,
intended to acquaint analytical chemists and others involved in environmental
chemistry with the power of the CRD method, is entitled “Solving
chemical problems of environmental importance using cavity ring-down
D, Analyst, 128, 117, (2003).) The cover figure shows J.J. Scherer’s
Ring-down Spectral Photography (RSP) image of a portion of the propane
spectrum. RSP, a multi-wavelength
variant of CRD is one of the emergent methods described in this paper which should
be of great use in atmospheric monitoring applications.
Abstract: Cavity ring-down (CRD) is a sensitive variant
of traditional absorption spectroscopy that has found increasing use in a
number of chemical measurement applications. This review focuses on
applications of cavity ring-down spectroscopy that will be of interest to
environmental chemists and analytical chemists working on environmental
problems. The applications are classified into direct monitoring approaches,
indirect analysis methods and ancillary studies and a differentiation is made
between field-tested instruments and proof of principle studies.
me for reprints if you are interested in this or any of our other work. DBA
I received my Ph.D. in Physical Chemistry from the University of Arizona in Tucson,
AZ in 1995.
My doctoral work, done under the direction of Dr. Mark A. Smith,
centered on the investigation of radical-molecule reaction dynamics at low
temperatures (1 -250 K.) I was awarded
an NRC postdoctoral fellowship at the National
Institute of Standards and Technology in Gaithersburg,
MD, where he worked with Dr. Jeffrey W. Hudgens from
1995-1997. In 1997, I accepted a faculty position in the chemistry department
at Portland State
My research experience and training straddles the traditional areas of fluid
mechanics, atmospheric, analytical and physical chemistry. A major
concentration has been on the development of novel measurement methodologies
for gas phase (free) radical chemical kinetics. We have measured the rate
parameters for a number of radical plus radical and radical plus stable
molecule chemical reactions under unprecedented conditions of temperature and
density. These reactions are known to be important to the chemistry extant in
the terrestrial atmosphere, as well as other planetary atmospheres and in
Current Research Statement
research focuses on the chemistry and physics of the terrestrial
troposphere. A major theme is the use of
innovative measurement methods for difficult analytical challenges. Our centerpiece project involves the use of
near-infrared continuous-wave excitation cavity ring-down (CWCRD) absorption
spectroscopic detection of radicals with pulsed laser photolysis in a kinetic
reactor system. This system allows us to
examine reaction kinetics of organic peroxy radicals which are key
intermediates in the atmospheric oxidation of volatile organic compounds
(VOCs). The novelty and power of this
kinetic method derive from the specific and sensitive determination of the
organic peroxy radicals using the CWCRD technique. This technique and recently obtained
confirmatory results are detailed in Journal
of Physical Chemistry A, 106, 8891, (2002). We are
currently investigating the temperature and pressure dependence of the rate
coefficient of the prototypical CH3O2 + CH3CH2O2
reaction. We have also begun kinetic and
spectroscopic investigations of the iso-propyl peroxy
A relatively new
project which we have initiated is the measurement of the stable products of
the reactions within the CWCRD reactor. Samples of the effluent from
the reactor are pressurized and concentrated and then analyzed by GC/MS and/or
GC/FTIR. These measurements support the
kinetics project by helping to establish the reaction mechanism which is being
observed and modeled. An example is the
CH3CH2O2 + CH3CH2O2
reaction system, where the ratio of acetaldehyde to ethanol produced in the
reaction and the secondary chemistry following the reaction is a measure of the
branching ratio into stable products vs. free radicals (which continue to react
in our system and in the atmosphere.)
combines the more traditional pulsed laser cavity ring-down approach with
standard aerosol handling techniques to produce a new type of portable
multi-wavelength transmissometer system for measurement of the optical
extinction of the atmospheric aerosol, including particle size
discrimination. Preliminary results and
a description of the apparatus are published in The Analyst, 126, 1216 (2001).
The co-author (Jared Smith) was an undergraduate
student who went on to work with Dr. Craig Taatjes at the Sandia
Combustion Research Facility and is currently in the graduate program in
Chemistry at UC Berkley. This instrument
recently participated in a laboratory-based group intercomparison experiment
called the Reno Aerosol Optics Study, which was administered by NOAA’s CMDL aerosol group and supported by NOAA-ACIP
(aerosol-climate interaction program) and DOE’s ARM
(atmospheric radiation measurement) program.
The results of the intercomparison will be presented in an upcoming
A fourth project
seeks to extend the selectivity of membrane inlet mass spectrometry (MIMS) in
measuring hydrocarbon concentrations in air samples. Because polluted air typically contains a
complex mixture of hydrocarbons, and MIMS does not produce separation, the
research focuses on ways of reducing the complexity of the mass spectrometric
results. An approach based on an ozone
reaction pretreatment step is described in Environmental
Science & Tech., 36, 4152, (2002).
Briefly, the ozone is used to convert alkenes into oxygenated species
which are invisible to MIMS, while alkanes are unaffected and continue to be
measured. Our current investigations are
with various types of reagent ions which may be used (in Chemical Ionization
mode) to simplify the mass spectra of permeated compounds.
A final project
(conducted and funded jointly with Dr. O’Brien) uses mass spectrometry to
follow reactions of atmospheric importance with essentially hands-off and
complete detection of reactants and products.
Hydrocarbons are oxidized by OH radicals and/or ozone and the complete
reacting mixture is continuously drawn into an ion trap mass spectrometer where
both products and reactants are analyzed.
The complex chemistry involved in these reactions can be probed quickly
and completely and rate parameters and/or details of the mechanism can be
D. B. Atkinson, “Tutorial Review: Solving chemical problems
of environmental importance using cavity ring-down spectroscopy”, Analyst, 128, 117, (2003).
F. Wedian and D. B. Atkinson,
“Ozone Modulation of Volatile Hydrocarbons Using Membrane Introduction Mass
Spectrometry”, Environmental Science
& Tech., 36, 4152, (2002).
D. B. Atkinson and J. L. Spillman, “Alkyl Peroxy Radical
Kinetics Measured Using CW-Cavity Ring-down Spectroscopy”, J. Phys. Chem. A, 106, 8891, (2002).
M. A. Ostrovsky, Y. V. Sergeev, D. B. Atkinson, L. V. Soustov,
J. F. Hejtmancik, “Comparison of Ultraviolet Induced Photo-kinetics for
Lens-derived and Recombinant b-crystallins”, Molecular Vision, 8, 72, (2002).
J. D. Smith and D. B. Atkinson, “A Portable Pulsed Cavity
Ring-Down Transmissometer for Measurement of the Optical Extinction of the
Atmospheric Aerosol”, Analyst, 126, 1216, (2001).
D. B. Atkinson and J. W. Hudgens, "Chlorination
Chemistry 2. Rate Coefficients, Reaction
Mechanism, and Spectrum of the Chlorine
Adduct of Allene", J. Phys. Chem. A., 104,
D. B. Atkinson and J. W. Hudgens, "Chlorination
Chemistry. 1. Rate Coefficients, Reaction Mechanisms, and Spectra of the
Chlorine and Bromine Adducts of Propargyl
Halides", J. Phys. Chem. A., 103,
D. B. Atkinson, J. W. Hudgens, and A. J.
Orr‑Ewing, "Kinetic Studies of the Reactions of IO Radicals
Determined by Cavity Ring‑Down Spectroscopy", J. Phys. Chem. A., 103,
D. B. Atkinson and J. W. Hudgens, "Rate Coefficients
for the Propargyl Radical Self‑Reaction and
Oxygen Addition Reaction Measured Using Ultraviolet Cavity Ring‑down
Spectroscopy.", J. Phys. Chem. A., 103,
A. Fahr, P. Hassanzadeh, and D. B.
Atkinson, “Ultraviolet Absorption Spectrum and Cross-sections of Vinyl (C2H3)
Radical in the 225-238 nm Region.”, Chem.
Phys., 236, 43 (1998).
D. B. Atkinson and J. W. Hudgens, "Chemical Kinetic
Studies Using Ultraviolet Cavity Ring‑Down Spectroscopic Detection: Self‑Reaction
of Ethyl and Ethylperoxy Radicals and the Reaction, O2
+ C2H5 ® C2H5O2.", J. Phys.
Chem. A., 101, 3901 (1997).
D. B. Atkinson, K. K. Irikura, and
J. W. Hudgens, "Electronic Structure of the BF2 Radical
Determined by ab initio
Calculations and Resonance Enhanced Multiphoton
Ionization Spectroscopy.", J. Phys.
Chem. A., 101, 2045 (1997).
D. B. Atkinson, V. I. Jaramillo, and M. A. Smith, "The
Low Temperature Kinetic Behavior of the Bimolecular Reaction OH + HBr (76 ‑ 242 K).", J. Phys. Chem. A., 101, 3356 (1997).
D. B. Atkinson and M. A. Smith, "Design and Characterization
of Pulsed Uniform Supersonic Expansions for Chemical Applications.", Rev. Sci. Inst., 66,
D. B. Atkinson and M. A. Smith, "Radical‑Molecule
Kinetics in Pulsed Uniform Supersonic Flows: Termolecular
Association of OH + NO Between 90 and 220K.", J. Phys. Chem., 98, 5797 (1994).