Education
B.S., Washington and Lee University
Ph.D., Penn State University
Professor of Analytical Chemistry
Location
323 St. Albert Hall
Phone: (718) 990-5221
Fax: (718) 990-1876
jespersn@stjohns.edu
Hours
Monday - Thursday 8:30 a.m. - 4:30 p.m.
Friday 8:30 a.m. - 3:00 p.m.
Research Projects
There are three areas of chemical analysis that I am working
on. These are Solid Phase Micro Extraction, Metabolomics and
Sol-Gel Sensors.
SOLID PHASE MICRO EXTRACTION
(SPME)
The technique involves a delicate micro-fiber encased in a syringe
needle. The fiber is protected by the syringe needle at all
times except when it is exposed to a sample and when it is exposed
to the high temperature of a chromatograph injection
port.
The micro-fiber can be immersed in liquids to adsorb dissolved
substances. The micro-fiber can also be exposed to the vapor
phase above a liquid to sample volatile components of a
sample. Samples may also be heated or stirred as
necessary.
For this project a list of possible ideas is available.
However, I am particularly interested in finding students who have
a significantly different type of sample to analyze. Students
are urged to investigate their thoughts by searching Scifinder
Scholar for "SPME and ..." entering their proposed analyte in place
of the ellipsis. The more specific the analyte and the more
unique it is will result in fewer references returned.
METABOLOMICS (with Dr. Raymond Ochs)
The essence of this project is that until the recent
expansion of, analytical techniques, particularly GC-MS and LC-MS,
metabolic studies were done one compound at a time. This was
slow an d tedious and also made relationships between different
substances sometimes difficult to ascertain. Modern
instrumentation should allow us to analyze many different species
quickly and easily in each sample. This will provide a clear
metabolic picture more quickly. This project will be combined
with Dr. Raymond Ochs "pathways" database as well as with novel
data mining techniques just announced by IBM.
SOL-GEL SENSORS (with Dr. Enju
Wang)
Sol-gels are precursors of glass structures made from the
hydrolysis of silane compounds. Two common compounds that
hydrolyze to give silicon dioxide are tetramethoxy silane (TMOS)
and tetraethoxy silane (TEOS). Along with certain additives
and dyes, sensors can be produced.