Abstract
A method has been developed and validated for the personal monitoring of COUNTER®, O,O-diethyl-S-[(tert-butylthio)methyl]phos-phorodithioate, terbufos, in air. COUNTER insecticide vapor is collected on standard NIOSH-type charcoal tubes at 150 mL/min for an 8-hour sampling period. When COUNTER insecticide exists as a dust as well as a vapor, a sampling train consisting of a mixed cellulose ester filter followed by a standard charcoal tube is used. The collected material in each case is desorbed with toluene and analyzed by gas chromatography using a nitrogen-phosphorus detector. Average collection efficiencies of 91.9% were obtained for the charcoal tube, and filter-tube sampling train systems. The sample generation system, collection medium, and analytical methodology are discussed.