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METHOD TO-10A <br /> Determination Of Pesticides And Polychlorinated Biphenyls In Ambient <br /> Air Using Low Volume Polyurethane Foam(PUF) Sampling Followed By <br /> Gas Chromatographic/Multi-Detector(GC/MD)Detection <br /> 1. Scope <br /> 1.1 This document describes a method for sampling and analysis of a variety of common pesticides and for <br /> polychlorinated biphenyls(PCBs)in ambient air. The procedure is based on the adsorption of chemicals from <br /> ambient air on polyurethane foam(PUF) or a combination of PUF and granular sorbent using a low volume <br /> sampler. <br /> 1.2 The low volume PUF sampling procedure is applicable to multicomponent atmospheres containing common <br /> pesticide concentrations from 0.001 to 50,ug/m3 over 4-to 24-hour sampling periods. The limits of detection <br /> will depend on the nature of the analyte and the length of the sampling period. <br /> 1.3 Specific compounds for which the method has been employed are listed in Table 1. The analytical <br /> methodology described in Compendium Method TO-l0A is currently employed by laboratories throughout the <br /> U.S. The sampling methodology has been formulated to meet the needs of common pesticide and PCB sampling <br /> in ambient air. <br /> 1.4 Compendium Method TO-10 was originally published in 1989. The method was further modified for indoor <br /> air application in 1990. In an effort to keep the method consistent with current technology, Compendium <br /> Method TO-10 has incorporated ASTM Method D4861-94 (1) and is published here as Compendium <br /> Method TO-10A. <br /> 2. Summary of Method <br /> 2.1 A low-volume(1 to 5 L/minute)sample is used to collect vapors on a sorbent cartridge containing PUF or <br /> PUF in combination with another solid sorbent. Airborne particles may also be collected, but the sampling <br /> efficiency is not known(2). <br /> 2.2 Pesticides and other chemicals are extracted from the sorbent cartridge with 5 percent diethyl ether in hexane <br /> and determined by gas chromatography coupled with an electron capture detector(ECD),nitrogen-phosphorus <br /> detector(NPD), flame photometric detector(FPD),Hall electrolytic conductivity detector(HECD), or a mass <br /> spectrometer(MS). For common pesticides,high performance liquid chromatography(HPLC)coupled with an <br /> ultraviolet(UV)detector or electrochemical detector may be preferable. This method describes the use of an <br /> electron capture detector. <br /> 2.3 Interferences resulting from analytes having similar retention times during GC analysis are resolved by <br /> improving the resolution or separation,such as by changing the chromatographic column or operating parameters, <br /> or by fractionating the sample by column chromatography. <br /> January 1999 Compendium of Methodsjor Toxic Organic Air Pollutants Page 10A-1 <br />