Skip to main content
ARS Home » Research » Publications at this Location » Publication #96280
Title: AIR SAMPLING OF AEROSOL AND GASEOUS PESTICIDES

Author
item AMIN, MOHAMMAD - UNIVERSITY OF TENNESSEE
item WOMAC, ALVIN - UNIVERSITY OF TENNESSEE
item BUI, QUY - UNIVERSITY OF TENNESSEE
item MUELLER, THOMAS - UNIVERSITY OF TENNESSEE
item Mulrooney, Joseph - Joe

Submitted to: ASAE Annual International Meeting
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/28/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: Drift of agricultural chemicals is a major concern to the producer and the general public. Drift reduces the effectiveness of pesticides and poses a potential hazard to the surrounding environment. Pesticide drift is a complex process often involving the movement of the chemical in either the solid, liquid, or gas phase (or combination of the three). To adequately evaluate drift potential of various pesticide application technologies, samplers are needed to quantify the various phase components of the drift. The objective of this research was to verify a rotary disk impactor (RDI) phase partitioning sampler. The RDI sampler was evaluated with aerosols and vapors under controlled conditions. The RDI technology efficiently collected aerosol drops of potassium bromide, clomazone, and malathion in drops from 2 to 20 microns. Drop separation efficiency by the RDI ranged up to 99.4%. Results indicated that RDI was also equally efficient in collecting gaseous pesticides (over 95%) as it was in collecting aerosols. The results from this study indicate that the RDI technology provides an improved sampling technique that improves our ability to quantify pesticide drift according to the amount of liquid, solid, and gas that is leaving the targeted area.

Technical Abstract: Rotating disk impactor technology was investigated for the collection of separate liquid and vapor phases of airborne pesticides and simulants. An RDI collected from 90 to 99% of potassium bromide, clomazone, and malathion aerosols when directly coupled to a nebulizer that produced drop diameters ranging from 2 to 20 microns. The RDI also collected over 95% of the mass of clomazone and malathion vapors when connected to a vapor generator. Ethylene glycol and n-decane were selected for the RDI collection well liquid based on (1) reduced volatile loss of the collection liquid for sampling periods observed up to 7 hr, (2) mean recovery efficiencies of 86 and 87% for clomazone and malathion, respectively for ethylene glycol, and (3) n-decane suitability as a pesticide carrier solvent for direct analysis by gas chromatography equipped with electron capture detector when the test pesticide can be analyzed by such a system. Conventional air sampling media, that may be used in conjunction with the RDI, were evaluated for th recovery of a selected pesticide. Clomazone was fortified on sampling media and subsequently subjected to various rates of air flow and operation time. Clomazone recovery for a 15-min., 1Lpm air flow rate from glass fiber filter, polyurethane foam, a fritted impinger, and a multi-element OSHA versatile sampler (OVS) were 66, 92, 84, and 73% respectively.