Citation:

ULRICH, E. M., D. R. HELSEL, AND W. T. FOREMAN. MATHEMATICAL MANIPULATIONS OF ENANTIOMERIC DATA. Presented at American Chemical Society Meeting and Exposition, Washington, DC, August 28 - September 01, 2005.

Impact/Purpose:

The goal of this task is to contribute to a better understanding of human exposure to pesticides, especially for small children. We will develop, evaluate, and refine methods to characterize sources and pathways in and around the residential environment. Specific methods of interest include those using gauze wipes as sampling media (hands, floors, surfaces, etc.) for compounds such as permethrin, cyfluthrin, diazinon, chlorpyrifos, and allethrin. We will support the science behind FQPA and assist the Office of Pesticide Programs (OPP) in the development of guidelines for the assessment of residential exposure and risk to pesticides. Specific research objectives include: (i) to apply analytical methods for the field measurement efforts of the Exposure Measurement and Analysis Branch (EMAB); (ii) to evaluate developed methods in support of the National Exposure Research Laboratory's (NERL) Human Exposure Measurement Project; (iii) to develop a plan for chiral research and method development; (iv) to develop multi-residue analytical methods in support of regional projects.

Description:

The oral presentation describes the alternative method of peak fitting for the measurement of enantiomeric parameters such as enantiomeric ratio (ER) and enantiomer fraction (EF). The talk describes the disadvantage of using typical integrators, mathematical calculations such as average of a group of samples, the impact of ratio functions, and average ERs to the EF scale conversions. It also highlights the advantage of the peak fitting method which minimizes analyst bias.

Record Details: