Whitley Burchett

Passive Sampling Using Thin Layer Chromatography

(Presented at the CWEA Conference
April 23, 2003 - Ontario, California)

W. Michael Stallard
Peter G. Green
Edward D. Schroeder
Casey LeBlanc, Whitley Burchett & Associates

ABSTRACT

An in situ solid phase extraction method, Thin Layer Chromatography (TLC) passive sampling, was investigated as a screening method for determining the presence of organic compounds in water. Organophosphorus (OP) pesticides were selected as a model for the development of TLC passive sampling for non-point source pollutants. In laboratory and field experiments, TLC passive sampling was demonstrated to be a simple and inexpensive screening method for qualitatively determining the presence of OP pesticides. The materials for the TLC passive sampler developed in this research cost $1.60. Organic compounds were sequestered from water during exposure times of hours to weeks. In field applications, TLC passive sampling was conducted in natural and engineered systems with two extraction mediums, C2 and C18, silica gel. Diazinon and chlorpyrifos were detected by analyzing the adsorbed compounds by High Performance Liquid Chromatography with Ultraviolet detection.