Professor and Chair
challenging problem facing analytical chemists is the development of
methodology and instrumentation for element selective speciation of complex
samples. The interfacing of spectroscopic and chromatographic techniques
overcomes a number of limitations exhibited in each field for element selective
speciation of compounds. Whereas conventional spectroscopic techniques can be
used to detect trace levels of any element, the ability to differentiate
between various species of an element can only be achieved through prior
separations. On the other hand, chromatographic techniques allow for the
physical separation of
compounds, yet conventional detectors have limited element selective
capabilities. A second area of in our research
program focuses on the development of instrumentation and methodology which can
improve analytical determinations for trace metals and halogenated organic
compounds typically found in the environment. We currently have contractual
arrangements for environmental
assessment of waterways and biota throughout the state of
Trace metal determinations for environmental analysis. We are currently contracted with the Virginia Department of Environmental Quality through VIMS/SMS for the determination of trace metal concentrations in river and estuary fish samples and sediments collected throughout
. We are also currently investigating mercury contaminations in wildlife in the Great Dismal Swamp for the U.S. Fish and Wildlife Service. Methodology and techniques utilized include sample digestions and preparation, strict quality assurance/control practices, pseudo clean room, contamination control, and extensive spreadsheet documentation. Instrumentation used for measurements includes graphite furnace atomic absorption spectrophotometry (GFAAS), flame atomic absorption spectrophotometry (FAAS), hydride generation/atomic absorption spectrophotometry (HGAAS), and cold vapor atomic fluorescence spectro-photometry (CVAFS) for measurements of metal concentrations. Virginia
Tasty fish morsels and dried sediments awaiting acid digestions.
GFAA methods for trace metal analysis. Graphite furnace atomic absorption spectrophotometry is an excellent instrumental technique for the determination of metals at ultra-trace levels in a variety of matrices. Past research has indicated that published methods for the determination of several environmentally significant metals do not work as one would expect. For example, methods have been developed for the successful determination of Cd and Pb in simulated matrices, but the ability to compensate for background absorptions in real matrices has been frustrating. Blood and sea water matrices have been particularly challenging. Chemical modifiers must be found which when added to the matrix eliminates or at least significantly reduces the background absorption of the sample with no interference to the desired element absorption. Methodology and techniques utilized include GFAA instrumentation, simulated sample matrices, standard and sample solution preparations, and systematic evaluation of specific chemical modifiers.
One project of interest is the determination of trace metals in copper artifacts recovered from archaeological digs in the
area. The trace metal levels in copper can provide information on the copper origins (European or Native American). Sample amounts used are incredibly small (~ 20-30 mg), thus normal dissolution techniques are inadequate for the sensitivity needed to detect some elements, particularly North American samples. We are currently examining micro-digestion techniques to dissolve very small quantities of sample into a minimum amount of solvent for GFAAS determinations. Unfortunately, matrix affects from the large amount of copper must be resolved for accurate quantitation. Preliminary results have shown that the concentrations of several elements (Pb in particular) are different by one to two orders in magnitude, thus allowing for confirmation of the copper source. This could lead to important anthropological discoveries if copper remains from Native American digs are of European origin. Jamestown
Native American beads (left) and artifacts from
digs (right). Note size relative to penny in center. Jamestown
Helium discharge detector for gas chromatography. A significant amount of our research interests is based on developing innovative analytical instrumentation which utilizes element selective, spectroscopic techniques for the detection of gas chromatographic eluents. We continue to focus on the development and utilization of high voltage, low frequency helium discharges which tend to contain significant populations of metastable atoms and/or molecules with sufficient energies to produce molecular dissociation and subsequent atomic excitation through collisional energy transfer processes. Element selective detection is best achieved in the near IR region of the spectrum, especially for the halogens, and in the low UV for S and P. These elements are of primary concern with respect to the determination of environmentally significant compounds. This mode of excitation has led to the development of a simple and reliable helium discharge detector (HDD) for element selective detection of GC eluents. The detector has been successfully used for element selective detection of halogenated organic compounds which are prevalent in the environment.
One area of interest currently being investigated is the feasibility of restricting the helium discharge to the confines of the exit of the GC capillary column used to separate the compounds. The net effect is to reduce the radiant cross section which in turn can improve spectral throughput and enhance limits of detection. We have had some limited success at this point, especially with improving limits of detection for halogenated compounds to low picogram levels. We are just beginning to apply this design for the direct determination of halogenated compounds in water at ppb levels without prior separation. We are also looking at the analytical merits of a charge coupled array detector for simultaneous elemental detection from the GC-HDD system. Methodology and techniques utilized include preparation of standard solutions on a micro-scale level, atomic spectroscopy and gas chromatographic instrumentation, data collection and chromatographic integration methods, quantitative methods from chromatographic data, and the trials and tribulations of instrumental development.
Closeup of the helium discharge. The discharge is one millimeter in diameter.
New methodologies for methylmercury determinations. Mercury is an increasing health concern, especially from the consumption of contaminated fish. Methylmercury occurs in nature via biomethylation of inorganic mercury pollutants, in particular mercury arising from atmospheric deposition into aquatic systems. Organic mercury is more lipid soluble and has a much longer half-life, therefore increasing toxicity. Methylmercury usually represents up to 85% of the total mercury in fish, although current FDA and EPA requires only total Hg determinations. Current digestion techniques include acid digestion, alkaline digestion, distillation and supercritical fluid extractions; however these techniques are lengthy, have no temperature control and sometimes yield low recovery. Current detection methods include cold-vapor atomic absorption spectrometry, cold-vapor atomic fluorescence spectroscopy and GC-AFS. CV-AAS and AFS is very effective for total mercury recovery; but they are not highly adaptable to mercury speciation. Other methods require highly specialized and in most cases inaccessible detectors for most conventional labs. We are currently developing new microwave techniques to improve fish tissue digestion as well as further the development of an extraction and detection method using GC-MS, a widely used instrument in chemical analysis. The primary focus is on utilizing ion selective detection in MS using tetraphenylborates as derivatizing agents for the methyl mercury. A new class of fluorinated tetraaryl or alkyl derivatives are also being synthesized to allow for detection via conventional GC-ECD (electron capture detection), such as the tetrakispentafluorophenylborate shown to the left to yield a methylpentafluorophenylmercury derivative for GC-ECD detection.
Recent Grant Support, Publications, and Presentations
· Virginia Department of Environmental Quality, “Trace Element Analysis of Fish and Sediment Samples”, Awarded for $70,890, sub-contract through VIMS, March, 2002.
· Virginia Department of Environmental Quality, “Trace Element Analysis of Fish and Sediment Samples”, Awarded for $60,750, sub-contract through VIMS, March, 2003.
· Virginia Department of Environmental Quality, “Trace Element Analysis of Fish and Sediment Samples”, Awarded for $61,240, sub-contract through VIMS, April, 2004.
· Virginia Department of Environmental Quality, “Trace Element Analysis of Fish and Sediment Samples”, Awarded for $83,475; sub-contract through VIMS, April, 2005.
Fish and Wildlife Services, “Mercury Analysis for Fish and Sediments Collected from the Great U.S. Dismal SwampNational Wildlife Refuge”, Awarded for $40,000, October, 2005.
· Virginia Department of Environmental Quality, “Trace Element Analysis of Fish and Sediment Samples”, Awarded for $82,365; sub-contract through VIMS, May, 2006.
Publications and Reports
· G.W.Rice “Trace Metals Determinations for Fish and Sediment Samples Submitted by the Virginia Department of Environmental Quality” Final Report prepared for the Virginia Department of Environmental Quality, May, 2002.
· G.W.Rice “Trace Metals Determinations for Fish and Sediment Samples Submitted by the Virginia Department of Environmental Quality” Final Report prepared for the Virginia Department of Environmental Quality, May, 2003.
· G.W.Rice “Trace Metals Determinations for Fish and Sediment Samples Submitted by the Virginia Department of Environmental Quality” submitted to the Virginia Department of Environmental Quality, May, 2004.
· G.W.Rice “Trace Metals Determinations for Fish and Sediment Samples Submitted by the Virginia Department of Environmental Quality” submitted to the Virginia Department of Environmental Quality, May, 2005.
· G.W.Rice “Trace Metals Determinations for Fish and Sediment Samples Submitted by the Virginia Department of Environmental Quality” submitted to the Virginia Department of Environmental Quality, June, 2006.
· G.W.Rice “Evaluation of Mercury Contaminants in Aquatic Species from the Great Dismal Swamp National Wildlife Refuge”, submitted to the U.S. Fish & Wildlife Service, August, 2006.
· Gary W. Rice; Katie E. Hodgdon*; Janine S. Ladislaw*; Amy E. Sprinkle* “Evaluation of a Low Cost Array System for an Element Selective Helium Discharge Detector for GC” presented at the 2001 Pittsburgh Conference and Exposition, New Orleans, LA, March 4-8, 2001.
· Gary W. Rice; Kristin Weidner* “Quantitation of Brominated Diphenyl Ethers in the Presence of PCBs Using Element Selective Detection” presented at the 2001 Pittsburgh Conference, New Orleans, LA, March 4-8, 2001.
· Tom Chen*, Kara Paulus*, Gary Rice “Relatively Rapid Detection of Polybrominated Diphenyl Ethers Using Element Selective Detection” Paper #1636, presented at the 2002 Pittsburgh Conference, New Orleans, LA, March 17-22, 2002.
· Chris Tamm*, Seth Vermaten*, Gary Rice “Interferences Associated with Microscale Trace Metal Determinations of Copper Artifacts” Paper #1666, presented at the 2002 Pittsburgh Conference, New Orleans, LA, March 17-22, 2002.
· Gary W. Rice, Tom Chen "Direct Injection of Water for GC Analysis of Trihaloforms Using an Economical Atomic Emission Detection System", Paper #30, presented at the 225th National ACS Conference,
, New Orleans, LA March 23-27, 2003.
· G. W. Rice, “Undergraduate Research in Chemical Analysis from A to Z”, Department of Chemistry,
; invited alumni keynote speaker for the 30th Annual Spring Undergraduate Research Symposium, James Madison University April, 8, 2005.
· Crystal Irwin*, Sara Costa*, Justin Williams*, Devon Shick*, and Gary Rice “Development of New Derivatizing Reagents for the Determination of Methylmercury in Fish” presented at the 2006 Pittsburgh Conference and Exposition, Orlando, FL March 12-17, 2006.
* Undergraduate student coauthors.
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Research Lab and Group
The "LAB". Welcome to the Rice lab, our home away from home. Tastefully decorated and equipped to handle the ups and downs of scientific curiosity. Our lab is equipped with state of the art instrumentation, including two PCs (one equipped with a stereo/subwoofer speaker system for audio/video research), a couch (for when deep pondering or a nap is required), a dart board (to research statistical variations in student agility), a variety of soul searching posters, sayings, etc. (for motivation), the usual scientific stuff (top loading and analytical balances, atomic fluorescence system for mercury determinations, the GC/helium discharge detection system), refrigerator and freezer (not for food!), and ample student desk space for everything to get lost.
The “couch” Eloquent tapestries The GC-HDD system Statistical research area Pack rat student desk
The "GROUPS" There are typically 3-4 students that work with me full-time over a ten week period in the summer (the pays not great, but the rewards are numerous, including several group lunches and outings). There are anywhere from 4-7 students that work "periodically" with me during the academic year through either Chem 191 (Freshmen Honors Research), Chem 291 (Chemical Research), Chem 409 (Senior Research), Chem 495-96 (Senior Honors Research), or Chem 695 (Master’s Research).
Senior bliss (Matt, Tom, and Andy); May, 2003 The whole enchilada. From left to right: Kathryn,
the Big Kahuna, Chris, Matt, Tom, Tony, and Andy
The girls of Summer, 2003 and Fall, Spring 2004. From left to right: The “Green Leafe” Group. From left to right: Eric, Liam, Kristen, Kathryn, the Big Kahuna, ,Katie, and Crystal. Tony, the Big Kahuna, Sara, Katie, Michelle, and Crystal. (Note “designer” lab coats) (
just finished her M.S. in February, 2006) Crystal
I have always taken the philosophy that no matter how bad of a day I may be having, never take it into the classroom. The only way to truly get students interested in what you are talking about is to show a genuine enthusiasm and excitement for science. I was flattered to be selected as one of the first three recipients of the University Professorships for Excellence in Teaching in 1996, and I continue to hold to those values and expectations.
My teaching interests are focused primarily in the analytical and general chemistry areas of our curriculum. I have taught the following courses and labs over my tenure at William and Mary:
Chemistry 103 General Chemistry I Chemistry 335 Principles of Inorganic Chemistry
Chemistry 308 General Chemistry II Chemistry 354 General Chemistry II Lab
Chemistry 309 Instrumental Analysis Chemistry 356 Quantitative and Inorganic Methods Lab
Chemistry 309L Instrumental Analysis Lab Chemistry 404 Advanced Analytical Chemistry
Chemistry 320 Introduction to Research
My current teaching duties include Chem 309 (a course intended primarily for junior level chemistry majors, Chem 309L (the instrumental analysis lab, that includes everything from determining the amount of trihaloforms produced from the chlorination of water to the higher alcohol impurities in whiskey), Chem 320 (intended to introduce students to literature searching techniques and writing a scientific paper), Chem 356 (a second semester general lab specifically designed for chemistry majors to enhance their preparation for the upper level laboratory experience), and Chem 404 (an advanced level analytical elective that expands on instrumental analysis topics as well as new areas such as surface analysis and lab-on-a-chip designs)
Welcome to the home/zoo, which illustrates that there is life beyond the laboratory! Below you will find some shots of home/zoo life in our 120 year old farmhouse, located over the river and through the woods in
(where we have lived since moving to Gloucester County because we couldn't find downtown Virginia ). In addition to the usual two legged creatures that occupy our home, you'll find a variety of four legged creatures who had no place to go but our humble abode. This includes (as of August, 2006) 18 dogs and16 cats, and an eel confined to an aqueous tank. Williamsburg
The humble abode (circa.1884) after a rare snow. The humble owner (circa.1954) The humble owner's "lap dog".
How many cats can sleep on one Dogs relaxing in the living room (plus one The not so humble
bench without falling off? dog/cat). They put us outside for the day. (and late) Munch