Many current and planned research projects rely on permeation of target analytes through polymer membranes. This process has been evaluated as a method for collecting environmental samples from air and water. Passive samplers for formaldehyde and ethylene oxide in air and a range of priority pollutants in water have been developed. At present, various classes of pesticides are being studying using this sampling approach. Beyond providing time weighted average samples; the approach also reduces or eliminates the need for toxic solvents. Protective barriers, such as gloves, represent another type of membrane where chemicals can be expected to permeate. Permeation characteristics of glove materials are being determined.
Development of improved glove materials is planned. These studies involve the development of models based on simple solubility tests. The goal is to create a simple approach for prediction of glove performance. Permeation also is being evaluated as a low cost GC/MS or LC/MS interface for select systems.
The method of Principal Component Analysis is being applied to a number of data sets. Research in this area falls into two general areas. There are several projects where the method is used to either identify or characterize complex chromatographic results obtained from samples such as whiskey, coffee, wine or other beverages. With these projects, the goals are to develop artificial intelligence systems that automatically identify contaminants, classify samples, or gain understanding about how the beverage was produced. The process also is being applied to three-dimensional data sets such as 2-D NMR and GC/MS. Using PCA it is possible to remove noise and artifacts from the data, dramatically improving signal to noise and data quality.
By using a mass spectrometer as a gas chromatographic detector, it is possible to employ stable isotopes of hydrogen, carbon, nitrogen and oxygen as tracers for evaluating a range of biological systems. Unlike studies involving radioactive labels, this approach not only provides information about the incorporation of a label - it yields specific location. Methods are currently being developed that determine enrichment levels and positional information for the majority of the amino acids and are being applied to bacterial and mammalian systems.
Figure 1. Quantification of priority pollutant metals as dibenzyldithiocarbamate complexes.
- E. Bodle and J. Hardy. Multivariate Pattern Recognition of Petroleum-Based Accelerants by SPME GC-FID, Anal. Chem. Acta, 589, 247-254, 2006.
- "Noise Reduction of GC/MS Data Using Principal Component Analysis," Lee, T.A.; Headley, L.M.; and Hardy, J.K., Anal. Chem., 1991, 63, 337.
- "Method for the Evaluation of the Permeation Characteristics of Protective Glove Materials by Organic Solids," Fricker, C., and Hardy, J.K., Am. Ind. Hyg. Assoc. J., 1992, 53, 745.
- "Adulterant in Whiskey: Detection and Identification by Principal Component Analysis," Headley, L., and Hardy, J.K., J. Food Sci., 1992, 57(4), 980.
- "Compositional Changes in Brewed Coffee as a Function of Brewing Time," Lee, T.A., and Hardy, J.K., J. Food Sci., 1992, 57(6), 1417.
- "The Effect of an Alternate Environment as a Collection Medium on the Permeation Characteristics of Solid Organics Through Protective Glove Materials," Am. Ind. Hyg. Assoc. J., 1994, 55(8), 738.
- "Use of 13C Nuclear Magnetic Resonance Spectroscopy and Principal Component Analysis for Automated Analysis of Styrene/Butandiene Copolymers," Walsh, N.G.; Hardy, J.K.; and Rinaldi, P.L., App. Spec. 1997, 51(6), 889.
- "Permeation Sampling of Halogenated Ether Priority Pollutants," Frantz, D., and Hardy, J.K., J. Environ. Science Health, 1998, A33 (3) 353-368.
- "Characterization and Classification of Ohio Wines Using Multivariate Data Analysis," Li, P., and Hardy, J.K., J. Wine Res. 10(3) 197-206 (1999).
- "Determination of Organophosphorous Pesticides in Water Using Permeation Sampling," Sun, Z., and Hardy, J.K., Adv. Environ. Res., 3(4) 49905-7 (2000).