Submitted to: Journal of Cotton Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/2/2002
Publication Date: 4/1/2002
Citation: Eiceman, G. A., Bergloff, J.F., Funk, P.A. Comparison of emission profiles for volatile organic compounds from cotton and polypropylene-based tarp. Journal of Cotton Science. 2002. v. 6. p. 40-51. Interpretive Summary: Detecting trace amounts of volatile organic compounds such as alcohols, aldehydes, esters, ethers, pheromes, and other chemical attractants for insects is necessary to understand insect response to and field dispersion of these chemicals. New technology created at NMSU was shown to rapidly and accurately separate and characterize various similar chemicals from these families at atmospheric pressure. This breakthrough makes a field portable device of unprecedented sensitivity finally possible. Pico gram detection limits in a hand held device operating in real time promises to greatly advance our understanding of plant-insect and insect-insect interactions as it becomes far easier to eavesdrop on their chemical language in their natural habitat.
Technical Abstract: A high electric field, radio-frequency ion mobility analyzer (RF-IMS) was used as a small detector in gas chromatographic separations of mixtures of volatile organic compounds including alcohols, aldehydes, esters, ethers, pheromes, and other chemical attractants for insects. The detector was equipped with a 2 mCi 63Ni ion source and the drift region for ion characterization was 34 mm wide x 20 mm long and 0.6 mm high. The rate of scanning for the compensation voltages was 60 V s-1 and permitted 4 to 6 scans to be obtained across a capillary chromatographic elution profile for each component. The RP-IMS scans were characteristic of a compound and provided a second dimension of chemical identity to chromatographic retention adding specificity in instances of co-elution. Limits of detection were 1.6 to 55 x 10-11 g with an average detection limit for all chemicals of 9.4 x 10-11 g. Response to mass was linear from 2 to 50 x 10-g with an average sensitivity of 4 pA ng-1. Separations of pheromones and chemical attractants for insects illustrated the distinct patterns obtained from gas chromatography with RF-IMS scans in real time and suggest an analytical utility of the RF-IMS as a small, advanced detector for on-site gas chromatographs.