Current Students
Emily Yourd , a fourth-year student, who is
working on multi-element preconcentration methods for ICP-MS
as well as new FI procedures for sample dilution and internal
standardization. She is interested in applications to forensic
science topics and is studying the determination of fingerprint
elements in bullet lead. A method for the removal of lead by
selective solid-phase extraction is under development. The
use of supported liquid membranes will also be evaluated.
David Scott , a fourth-year student, is working
on the development of HG procedures for AAS; in particular
the simultaneous determination of As and Se will be studied.
Methods based on the use of solid reagents will be evaluated.
Some of these procedure will develop further the methods developed
by Pablo Carrero. Hydrobromic acid with potassium bromate is
looking promising.
Theresa Dearborn , a fourth-year student,
is working on the integration of teaching at the K-12, undergraduate
and graduate level. She will develop some OWL material for
the teaching of statistical evaluation of data and co-ordinate
a project on the determination of As in soils near pressure-treated
decks. (joint project with Professor Vining). Theresa is
now a full-time high school chemistry teacher at Mohawk Regional
School.
Rameh Hafezi , a fourth-year student, who is working on separation
and detection of Se-containing bioploymers. The nature of the
selenium species in yeast are of interest and she will continue
to develop the HPLC-ICP-MS and HPLC-MS procedures that have
been devised by previous students. (joint project with Professor
Uden). Rameh will shortly finish her MS thesis.
Chey Kahakachchi , a second year student, will be working
jointly with Professor Uden on aspects of the determination
of Se, Hg and As in environmental samples, particularly soils.
Harriet Totoe, a first second student, will be working jointly
with Professor Uden on aspects of the determination of Se,
Hg and As in environmental samples. Her initial work will be
on the HPLC separation of organoseleno compounds extracted
from selenized yeast with element specific detection (ICP-MS).
Jum Chuachuad , a first year student, who will continue work
related to determination of elements by hydride generation
with atomic spectrometry.
Richmond Ampiah-Bonney , a first year student, who will work
on the development of low cost instrumentation for teaching
analytical chemistry in undergraduate and high school situations.
David Takuwa , a first year student, who will work jointly
with Professor Uden on speciation studies by chromatography
linked to atomic spectrometric detection.
Charli Asta-Ferrero , a first year student who is planning
to be a high-school teacher after getting an MS, will be working
jointly with Professor Uden on the development of experiments
to teach chemistry through the analysis of everyday chemicals.
Brian Weitze , an undergraduate student, is working on the
removal of lead by precipitation and filtration in a flow injection
manifold connected directly to an atomic absorption spectrometer
as the first stages in a method for the characterization of
bullet lead materials.
Three academic visitors will spend time in the
group during the summer of 2001.
Dr. Yasemine Bakircioglu is visiting from Turkey for three
months working on the determination of lead by FI-SPE-FAAS
with Pb.Spec extractant.
Dr. Ahmed Youseff from the University of Cairo
will work on aluminum speciation by FI-ETAAS with liquid-liquid
and solid phase extraction.
Dr. Susana Rio-Segada from the University fo
Vigo will work for a few months on the mercury speciation project.
Former Group Members
Dr. Steve Bysouth (Oct 89 - Oct 91), a postdoc, who was working
on aspects of flow analysis atomic spectrometry and whose research
was concerned with the possibilities of supercritical carbon
dioxide as a carrier stream in a flow-injection extraction
system with subsequent high efficiency nebulization. Steve
was also working on a computer model of flow processes in open
tubular reactors of typical flow injection dimensions. Steve
went first to Shell Development, Houston, TX and is now in
Holland.
Dr. Susan Darke , a postdoc, who was constructing
and evaluating the performance of a laser ablation system for
solid sampling, initially for flame atomic absorption spectrometry.
The system is currently configured with a Nd:YAG laser (Q-switched
and frequency doubled to 532 nm) capable of delivering 300
mJ per pulse. Sue is now with Sun Oil, Philadelphia, PA.
Dr. Mary Carroll , a postdoctoral, was working
on aspects of flow injection with particular reference to novel
spectrophotometric detector design incorporating laser diodes.
Work will be concerned with construction of a simple absorption
spectrometer, based on light emitting diodes and photodiode
detectors, for time-based measurements. Mary is now assistant
professor in the Department of Chemistry, Union College, Schenectady,
NY.
Ph.D. Students
Thomas Gluodenis , a Ph.D. student, was devising
methods of dealing with solid samples. This involved the use
of flow injection techniques for on-line digestion prior to
atomic spectrometric analysis. Samples were processed by the
transport of slurries or suspensions through reaction zones.
Microwave assisted digestions were developed. Tom spent 9 months
working on an internship at Perkin-Elmer. His first employment
was with P-E. he has now moved to Hewlett-Packard (now Agilent).
Rodney LaRue , a Ph.D. student was currently evaluating the
use of a new magnetic susceptibility balance equipped with
a flow cell as a detector for flow injection. Future work will
involve the use of flow injection/continuous flow techniques
for on-line matrix removal prior to introduction of sample
solutions into electrothermal atomizers. A number of strategies
will be tried including liquid-solid and liquid-liquid extraction.
He is now employed by AstraZeneca USA Inc.
Chris Hanna , a Ph.D. student, was devising flow injection
procedures for the generation of volatile analyte derivatives.
The general aim of these studies is to develop on-line methods
of matrix removal and preconcentration. Work will be concerned
(a) with the improvement in methods for the hydride-forming
elements and for mercury by the use of on-line matrix removal
and/or preconcentration and (b) with the development of methods
for the generation of volatile derivatives (such as chelates,
alkyls or carbonyls) for a range of other metals. Manifolds
will borrow techniques already developed for the HPLC-GC combination.
Chris worked first for the Perkin-Elmer Corporation, but is
now employed by Transgenomic, a biotech company near Boston.
Stuart Chalk , a Ph.D student was developing flow injection
methods for the determination of ultratrace concentrations
of anions. Work was concerned with the optimization of manifold
design and the use of membrane reactors for the introduction
of reagents without dilution. Some attention was given to the
possible use of solid reagents for solution spectrometric detection.
The work resulted in the development of membrane based devices
for reagent introduction. Stuart finished in August 1994 and
went to a post-doctoral position at Duquesne University with
Professor Kingston. He is now assistant professor at the University
of North Florida.
Roger Echols , a Ph.D. student, was evaluating the use of
flow injection and continuous flow techniques to study chemical
reaction kinetics and thermodynamics. Early work involved a
study of analytical applications of oscillating reactions.
He developed methods for measuring reaction rates and formation
quotients as well as sorting out some of the sources of imprecision
in the doublet peak method. Roger finished in August 1994 and
is currently assistant professor at the University of Minnesota,
Morris.
Maiella Ramos , a Ph. D. student researched (under the joint
direction of myself and David Curran) into the analytical applications
of various types of spectroelectrochemistry. Initial work is
concerned with the construction of a flow-cell for the spectroelectrochemical
study of various drug molecules by FTIR (ATR) and amperometry.
Reaction mechanisms will be studied as well as producing a
new detector for flow analysis procedures. Maiella finished
in June 95 and following a post-doctoral position in Washington
is now a faculty member at the University of Puerto Rico.
Ebenezer Debrah , a Ph.D. student worked on the design and
performance of flow-injection manifolds for matrix removal
and preconcentration based on precipitation and chemical vapor
generation reactions. The manifolds will be directly coupled
with atomic spectrometric detectors as well as indirectly via
the recirculating loop design. Ebebnezer finished in June 1995
and had a post-doctoral position with Perkin-Elmer in Norwalk,
CT. He is currently working for Sciex in Toronto.
Juan Ivaldi , who was an employee of Perkin-Elmer during his
Ph.D. studies worked on the evaluation of the performance of
an ICP optical emission spectrometer based on the use of an
echelle spectrometer and a solid state detection device. Aspects
of sample introduction and pretreatment as well as enhancement
of signal to noise ratio and the reduction of spectral interferences
will be studied. The advantages of axial viewing were also
examined. Juan is currently working for CETAC.
Ms Honghong Ge , a Ph.D. student, who has been working with
ICP-MS with particular reference to the use of FI sample handling
procedures. One area are of immediate interest is the use of
FI procedures for on-line dilution (in particular the recirculating
loop method), a project in collaboration with Perkin-Elmer,
who provided the instrument. She is also developing methods
of speciating selenium compounds in vegetables by HPLC-MS.
The final part of her project concerned the use of FI introduction
fro ICP-OES. She finished in December 1996 and is currently
working in Atlanta, GA.
Mr. Pete Yehl , a Ph.D. student who wa evaluating the analytical
potential of FI sample introduction for plasma atomic fluorescence
spectrometry. The work was be concerned with the determination
of some elements of interest to the US Geological Survey, who
provided the instrument, including As, Se and Au. He developed
procedures for arsenic speciation in soils and sediments contaminated
with run-off from timber treated with chromated copper arsenate.
Pete now works for Merck Sharpe and Dohme in Rahway, NJ.
Paul Becotte-Haigh , a Ph.D. student who was working on aspects
of ICP-MS with particular reference to flow injection sample
introduction. He evaluated possible methods for the determination
of As in gold; an analysis which suffers from a number of interference
effects. He also studied the possible uses of the chemical
reactions in an internal combustion engine as a source for
atomic spectrometry. Paul now works for Ion Track Instruments.
Robert Ellis , a Ph.D. student, whose studies related to the
determination of selenium in biological matrices by the use
of flow injection hydride generation atomic absorption spectrometry.
He also investigated the generation of lead and selenium hydrides
with trapping inside a graphite furnace. He investigated the
role fo surfactants in the gneration of arsine and of the sample
volume in setting detection limits in FI-HG-AAS. The work was
extended to a study of the possibilities of FI digestion procedures
using microwaves. Robert now works for Gedex, Toronto.
Neil Fitzgerald , a Ph.D.
student, who was looking at ways in which microwave energy
can be used to enhance sample pretreatment and introduction
for plasma spectrometry. His work involved both on-line digestions
and aerosol generation and desolvation. He successfully built
a desolvation device based on a multi-strand Nafion dryer
and showed that it substantially reduced the ArO interference
on Fe in ICP-MS. He built a pressure sensor for the FI "high" pressure
microwave digestion system and redesigned the digestion
cell. He developed a theory for the microwave interaction
(or lack of it) with water droplets. Neil is currently
a faculty member at Marist College.
Zikri Arslan , a Ph.D. student who developed methods for the
determination of trace elements in marine plankton (a National
Oceanographic and Atmospheric Administration project joint
with Professor Uden). He studied multi-element determinations
in silicate matrices and seawater by ICP-MS. He showed that
it was possible to use chromosorb 102 for multi-element preconcentration
frrom sea-water and devised a slurry sampling method for the
determination of lead in plankton by graphite furnace AAS.
Zikri is doing postdoctoral work at in marine science at the
NOAA laboratory, Sandy Hook, NJ.
Cesar Vargas , a Ph.D. student, who developed new methods
of chemical vapor generation for the determination of lead,
and cadmium by atomic absorption spectrometry. His work involved
chemical vapor generation. His work was focused on the determination
of cadmium by cold vapor procedures, and on optimization of
the generation chemistry for lead, in particular the role of
the gas-liquid separator and of impurities in the key reagent,
potassium ferricyanide. He developed a method for the determination
of lead in calcium supplements. Cesar is with Procter and Gamble
in Mexico City.
Hakan Gurleyuk , (joint project with Professor Uden) a Ph.D.
student, continued the work started by Peter Yehl on the biomethylation
of arsenic in soils. He developed an HPLC methods for the separation
of four arsenic species, As(V), As(III) monomethyl and dimethyl
arsenic (V). He has also developed a flow injection slurry
transport system for extracting analytes from soils. He started
work on a sepciation procedure based on hydride generation
with trapping on a Peltier-cooled material followed by sequential
thermal release. He and Chris Palmer developed a new nebulizer
for ICP spectrometry based on three concentric silica capillaries.
Hakan is workling for Frontier Geosciences in Seattle, WA.
Chris Palmer , a Ph.D. student, is continuing some of the
work of Peter Yehl on the plasma fluorescence instrument. The
goal is to develop this as an element specific detector for
chromatographic detection, with applications to environmental
samples. He will also continue the work of Paul Becotte-Haigh
on the internal combustion engine source. He has devised methods
for the measurement of Se and S by simultaneous atomic fluorescence
and molecular emission. He is also working on FI-based procedures
for the speciation of Hg and of Al. Work on the determination
of inorganic mercury and methylmercury has been successful.
Chris is now wrking for the New York State Health Lab in Albany,
NY. MS Students.
Elizabeth Grzeszczyk , an MS student, was working on a problem
of industrial relevance concerning the quantification of calcium
species in charcoal using flow injection procedures. A combined
visible absorption/atomic absorption procedure was devised
to determine carbonate and oxide. Beth submitted her thesis
in 1992 and is currently employed at Boehringer Ingleheim,
Milford, CT.
Anil Deisingh , an M.S. student, who worked with the development
of FI sample pretreatments involving heterogeneous reactions,
mainly solid/liquid, for flame atomic absorption spectrometry.
He will also develop a method for the determination of calcium
species in charcoal. Anil finished in August 1995 and returned
to a teaching position in the West Indies. He is now pursuing
Ph.D. studies at Toronto.
Shyamala Ivatury , an MS student, is evaluating the need for
developments in the undergraduate curriculum with particular
reference to the role of the instrumental analysis course and
associated laboratory class. The work will include the development
of low cost flow injection spectrometers. Sam finished in September
1996 and is working for Boehringer Ingleheim.
Supaporn Kradtap , an MS student, who wishes to develop methods
for the determination of elements of environmental interest
by FIAS procedures these will include chemical vapor generation
of cadmium and lead species after preconcentration by solid
phase extraction. Supaporn finished in May 1996 and moved to
graduate studies at the university of Cincinnati.
June Kwak , completed the requirements for a non-thesis MS
degree in June of 97.
Nils Sundin , a Ph.D. student, was working on the improvement
of analytical methodology for the determination of elements
via chemical vapor generation using flow injection atomic absorption
spectrometry. Work concentrated on the determination of selenium
in urine and high salt matrices. Nils returned to Canada in
early 1997 and has not (yet) completed his Ph.D.
Undergraduate Students
Mike Solomon and Paul
Haigh , conducted senior
year research projects in the group during the Fall semester
1991. Their work was concerned with aspects of the double
peak FI method and of vapor generation for atomic spectrometry,
respectively. Paul returned to UMass for Ph.D. studies
in my group. Nancy Bradley and Jeremy
Knapczyk, conducted research projects in their senior year
in the spring of 93. Their work was concerned with the
use of flow injection techniques to develop the analytical
applications of magnetic susceptibility and ICP-MS. The
magnetic susceptibility work was continued by Kyle
Normandin in the spring of 97. In spring 1999, David
Magnusson performed
some studies of the transport of slurries in a flow injection
system. He used silica particles and compared the dispersion
pattern with that of a dye in solution.
Academic Visitors at UMass
1990: Ebenezer Debrah
(University of Technology, Loughborough, UK) 8 months,
Ahmad Al-Alousy (University of Leicester, UK) 3 months, Oswald
Platteau (Intevep Corporation, Caracas, Venezuela) 2 weeks.
1991: Stephen Offley (University of Technology, Loughborough,
UK) 3 months. Oswald Platteau (Intevep Corporation, Caracas,
Venezuela) 2 weeks.
1987/8: Dr. Nusret Ertas, a visitor from Turkey, worked
on the determination of lead by trapping the hydride on
a slotted quartz tube in a fuel-lean flame followed by
reatomization in a pulsed fuel-rich flame. He also helped
with the determination of Pb in urine by FI-HG-AAS.
1988: Dr. Latif Elci, a visitor from Turkey, worked on
the determination of lead by trapping the DDC derivative
on chromosorb and release with suitable solvents for determination
by FAAS or HGAAS.
1995-8: Pablo Carrero (University of Los Andes, Merida,
Venezuela) worked on a new method for generating the hydrides
of selenium and arsenic by co-immobilization of the anionic
precursors together with borohydride on an anion exchange
resin.
1999: Steffen Nielsen (Technical University of Denmark)
worked on the use of solid phase extraction with the introduction
of organic solvents into the plasma source mass spectrometer
for multi-element determinations.
Former UK Research Group
Between 1978 and 1990, fourteen students successfully
completed Ph.D. studies and two students completed M.Phil.
research studies under my supervision. In addition, some 15
undergraduate and 46 M.Sc. projects were carried out under
my direction.
