See: C-Y. Peng, S. Batterman, “Performance Evaluation of a Sorbent Tube Sampling Method Using Short Path Thermal Desorption for Volatile Organic Compounds” Journal of Environmental Monitoring, in press (2000).
Our laboratory focuses on the measurement of volatile organic compounds at trace levels in environmental samples, including air, soil, water and biological samples (breath, urine and blood). We emphasize both method development and environmental applications.
Selected analytical and sampling instrumentation in the laboratory is described below. Additional instrumentation is available elsewhere in the Department of Environmental Health Sciences and the University of Michigan.
GC-MS. A Hewlett Packard 6890/5973 gas chromatograph/mass spectrometer running Chemstation, Version G1701BA/B.01 is used for positive identification and quantification of VOCs and trace compounds. This system includes an on-column injector, APC, a turbomolecular pump, ion gauge controller, NT-based work station, and the 1999 NIST mass spectral library.
GC/ECD/FID/TCD. Three Varian 3700 GCs are equipped with electron capture, flame ionization, or thermal conductivity detectors interfaced to computer-based data acquisition and control systems.
| GC/TD, EPA TO-17.
Short-path thermal desorption/preconcentration for VOCs collected using sorbent tubes (EPA Method TO-17). An automated short-path thermal desorption/cryofocusing system (Model 2000, Scientific Instrument Services) is automated and interfaced to a GC-MS.
The photo the automated thermal desorber/cryofocus unit (mounted on top of the GC with the power supply/logic unit to the
right (under the telephone).
See: C-Y. Peng, S. Batterman, “Performance Evaluation of a Sorbent Tube Sampling Method Using Short Path Thermal Desorption for Volatile Organic Compounds” Journal of Environmental Monitoring, in press (2000). |
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EPA TO-14/15. Whole air sampling VOCs collected in canisters (EPA methods TO-14, TO-15). A Tekmar 5010 cryogenic preconcentration and thermal focusing unit is interfaced to a Varian 3400 GC with an on-column injector and FID.
| Headspace. Headspace analysis for VOCs in water, blood, urine, etc. A Tekmar 7000/7050 Headspace Autosampler Carousel Combination with 50 sample capacity and autocalibration capability is interfaced to a Varian 3700 GC.
This unit is used for the analysis of volatile compounds in water, blood and other
fluids.
See, for example, S. Batterman, H. Xiao, A. Franzblau, "Bioindicators for Methanol Exposure: Effect of Chilled and Frozen Sample Storage," Applied Occupational and Environmental Hygiene, 11, 1, 25-29, 1996. |
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Continuous FID/PID. For continuous measurements, a Horiba model FIA-23A total hydrocarbon analyzer using flame ionization detection and 3 ModuRae PDM-10A portable photoionization detectors with laptop PC data systems are available.
| Fast GC. A Chromatofast Cryointegrator G (HSGC inlet and trap) allows extremely rapid determinations of VOCs using a Varian 3400 GC. Post-doctoral fellow Chung-Yu Peng operates a Varian GC equipped with a Chromatofast GC inlet (small white box to right) and a Tekmar cryofocus unit (gray box on top). |  |
FTIR. A Bomem MB-100A Fourier transform infrared spectrometer system, designed for air sampling application, utilizes Hanst 6, 20 and 250 m gas cells, a CDM detector, the Hanst spectral library data set, and SpectraCalc control and custom ordinary least squares software.
Bioaerosol and particulate sampling. Available samplers include low and medium flow samplers, Anderson 7-stage impactors, and PM2.5 impactors.
IR/UV. Beckman IR/UV spectrophotometer.
Sorbent tube sampling for VOCs. Samples are collected using personal sampling pumps (e.g. SKC model PCXR7 microprocessor controlled) and flow splitters (MSA), or AC-line powered sampling pumps. Sorbent tubes are conditioned off-line using a 24-tube conditioning oven (Model A-24, Scientific Services, Inc.). We have the ability to calibrate flow, prepare primary standards, etc.
The photo shows a personal sampling pump equipped with a flow splitter/controller and two sorbent tubes. This system can collect replicate samples up to 24 hours in duration.
| Sorbent tube sampling for VOCs. Samples are collected using personal sampling pumps (e.g. SKC model PCXR7 microprocessor controlled) and flow splitters (MSA), or AC-line powered sampling pumps. Sorbent tubes are conditioned off-line using a 24-tube conditioning oven (Model A-24, Scientific Services, Inc.). We have the ability to calibrate flow, prepare primary standards, etc. The photo shows a personal sampling pump equipped with a flow splitter/controller and two sorbent tubes. This system can collect replicate samples up to 24 hours in duration. |  |
Canister sampling. Air sampling equipment includes 30 6L Summa passivated sampling canisters, 3 subatmospheric pressure sampling systems, 3 pressurized sampling systems, and a Scientific Instruments Systems canister cleaning.
Miscellaneous. Additional facilities include flow measurement and control devices, primary flow calibration standards, three dynamic dilution test gas generators, Addco model 737 pure air source, two automatic humidifier systems, sampling pumps, Ohaus and Cahn electro-microbalances, drying ovens, humidity monitors, and wet lab facilities. A number of separate laboratories are available, equipped with chemical fume hoods, point and area ventilation systems, chemical storage units, refrigerators, and house utilities. A small machine shop is maintained in-house; complete machining and fabrication facilities are located elsewhere on campus.
The next page will direct you to recent or ongoing research in the area of indoor air quality (IAQ.