WRRC's Chemistry Lab

The WRRC Analytical Chemistry Laboratory is housed in 700 sq. ft. of space in the engineering building, Holmes Hall, room 181. WRRC works closely with the department of Civil and Environmental Engineering, and, together, they have furnished the laboratory with up-to-date, and state-of-the-art, equipment for the analysis of environmental pollutants at trace levels of parts per million (ppm), parts per billion (ppb), and even parts per trillion (ppt). This includes Volatile and Semi Volatile Organic compounds like Petroleum Hydrocarbons, Industrial Solvents, Explosives, Pharmaceuticals & Personal Care Products (PPCPs), and Endocrine Disruptors like Organochlorine Pesticides, Polychlorinated Biphenyls (PCBs), Polynuclear Aromatic Hydrocarbons (PAHs). The laboratory is available to graduate students and researchers in the Environmental Engineering program and those working with the Water Resources Research Center.

Major instruments in the lab include:

HP 5890 series II Gas Chromatograph (GC)
with Flame Ionization
(FID)and Electron Capture (ECD) detectors, Liquid InjectionAutosampler, and Tekmar 3000 Purge & TrapConcentrator. This instrument is the workhorse of the lab. Using the FID, it can analyze any compound that has a C-H bond. The FID is the generic, default detector in the GC world. It's most often used for detecting petroleum hydrocarbons like gasoline, diesel, jet fuels, etc. The ECD is a more sensitive detector for halogenated compounds. It does well with chlorinated pesticides and PCBs. Volatile halogenated compounds like freons and chlorinated industrial solvents can also be detected when using the purge and trap injector. Data from this instrument is collected on computer by ChromPerfect software which can process the data, compare it to calibration curves, and print out the results automatically. Large batches of samples can be run overnight, or over the weekend using the autosampler.
ThermoFinnigan Polaris GC/MS

This is a Gas Chromatographwith an ion trap Mass Spectrometer (MS)detector. In addition to the usual retention time data, this detector provides compound-specific information via the unique fragmentation pattern of the compound being analyzed. This pattern can be compared to a database of over 100,000 compounds for positive identification of the analyte. The Ion Trap feature of this instrument allows for multiple fragmentation(MS/MSn) of selected ions for greater certainty of compound identification and quantitation. It's external ionization capability allows selected ions to be isolated from matrix interferences before going into the trap. This instrument is setup for the analysis of Semi Volatile Organic Compounds (SVOC). It also has an autosampler and sophisticated Xcalibur software for instrument control as well as data analysis and processing.

It is said that only 20% of the compounds in the world can be analyzed by Gas Chromatography (GC). Compounds that are thermally labile (destroyed by heat) or react with the inner workings of a GC at the elevated temperatures required for this type of instrument cannot be easily analyzed by this technique. The other 80% prefer to be analyzed at room temperature by Liquid Chromatography (LC). Fortunately, we have these types of instruments too:
ThermoFinnigan Surveyor HPLC with Photo Diode Array (PDA) and Shimadzu RF-10AxL Fluorescence detectors

High Performance Liquid Chromatography (HPLC), or high pressure liquid chromatography as it used to be known, uses liquids instead of gases to carry the sample through the chromatographic process. This instrument has a Photo Diode Array detector as well as a Fluorescence detector which can see compounds that naturally fluoresce, like polynuclear aromatic hydrocarbons (PAHs), as well as estrogens and alkyl phenols.

ThermoFinnigan Surveyor/LCQ (LC/MS)

This is another HPLC instrument equipped with a Photo Diode Array (PDA) detector. A PDA is a UV/Vis detector which can also scan a range of wavelengths every fraction of a second and provide a profile of a particular unknown compound which can then be compared to a database for a more positive identification. If that's not enough, a mass spectrometer (MS) detector lies at the end of the analytical sequence to provide mass spectral data for positive identification. It has multiple fragmentation capabilities (MSn) similar to the GC/MS above.

Dionex ICS-1100s(IC)

The above items are typical high-end instruments in an environmental laboratory for the analyses of organic compounds. What about basic inorganic ion analyses? For that we have: dual Dionex ICS-1100s(IC). These instruments can analyze Anions [fluoride (F-), chloride (Cl-), nitrate (NO3-), phosphate (PO4-2), sulfate (SO4-2)] and/or Cations [sodium (Na+), potassium (K+), ammonium (NH4+), calcium (Ca-2), magnesium (Mg+2)], as well as other ions in water samples. Its autosampler will even filter your samples for you before analysis.

Shimadzu TOC-V total Organic Carbon (TOC) analyzer with a Total Nitrogen (TN) detector

This instrument will analyze liquid samples for Total Carbon (TC), Inorganic Carbon (IC), and Total Organic Carbon by difference (TC - IC = TOC). It can also analyze non-purgeable organic carbon (NPOC). It's capable of measuring Total Nitrogen (TN) concurrently with TOC analysis. It also has an autosampler and computer data acquisition and instrument control software. And we have the 5000A SSM attachment for solid sample analysis.

Gemini VI Surface Area and Pore Density Analyzer Our most recent acquisition is a Micromeritics Gemini VI Surface Area and Pore Density Analyzer. Surface area analyzers and pore size analyzers may be used to analyze a number of factors including pore distribution, pore volume, specific surface area, and total surface area. Surface area helps determine such things as how solids dissolve, burn, and react with other materials. To determine the surface area, surface area analyzers and pore size analyzers measure solid samples that have been pretreated by some combination of heat, vacuum and/or flowing gas to remove adsorbed contaminants acquired from atmospheric exposure. With this instrument we will be analyzing soils and activated carbons.

Brookhaven Instruments Zeta Potential and Particle Size analyzer

One of our newer instruments is a Brookhaven Instruments Zeta Potential and Particle Size analyzer. Zeta potential is a function of the surface charge of particles, any adsorbed layer at the interface, and the nature and composition of the surrounding medium in which the particles are suspended. It is usually of the same sign as the potential actually at the particle surface but, unlike the surface potential, the zeta potential is readily measured by experiment. Because it reflects the effective charge on the particles and is therefore related to the electrostatic repulsion between them, zeta potential is extremely relevant to the study and control of colloidal stability and flocculation processes.

In another facility on campus, graduate students also have access to an ICP/MS for heavy metals analysis if needed for their research. Sample Preparation is often a major part of the analytical process for organic compounds. For that we have Solid Phase Extraction (SPE) equipment and an N-Evap Nitrogen Evaporator for concentrating sample extracts. Our Chemistin charge of all this equipment is Joseph Lichwa. Joe is a 15-year veteran of major commercial environmental labs in Hawaii. He has done just about every kind of environmental analysis there is using EPA drinking water, wastewater, and hazardous waste methodology. He knows how to use, maintain and repair all the instruments in the lab. He trains researchers and students to use the equipment, and reviews their data to make sure they are getting meaningful results.

Some research projects currently taking place in the lab include:
  • Adsorption of pesticides on granulated activated carbon (GAC).
  • Sorption of pharmaceutical compounds in soil.
  • Leaching behavior of selected pesticides.
  • Pharmaceutical residues in wastewater influents and effluents.