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Pesticides/PCBs Method TO-10A <br /> 13.1.9 If quantification is performed using an internal standard,a relative response factor(RRF)is calculated <br /> by the equation: <br /> RRF <br /> (Ii)(CO <br /> where: <br /> I,= integrated area of the target analyte peak,counts. <br /> Is= integrated area of the internal standard peak,counts. <br /> Gs= concentration of the internal standard,ng/µL. <br /> C,= concentration of the analyte,ng/µL. <br /> 13.1.10 The concentration of the analyte(Ca)in the sample is then calculated as follows: <br /> C = (I'Xci) <br /> Ca (RRF)(Ii) <br /> where: <br /> Ca= concentration of analyte,ng/m3 <br /> I,= integrated area of the target analyte peak,counts. <br /> RRF= relative response factor(see Section 13.1.10). <br /> 14. Sampling and Retention Efficiencies <br /> 14.1 General <br /> 14.1.1 Before using Compendium Method TO-10A,the user should determine the sampling efficiency for <br /> the compound of interest. The sampling efficiencies shown in Tables 2, 3, 4, and 5 were determined for <br /> approximately 1 m3 of air at about 25'C, sampled at 3.8 L/min. The SE values in these tables may be used for <br /> similar sampling conditions; for other compounds or conditions, SE values must be determined. <br /> 14.1.2 Sampling efficiencies for the pesticides shown in Table 6 are for a flowrate of 3.8 L/min and at 25'C. <br /> For compounds not listed, longer sampling times,different flow rates,or other air temperatures,the following <br /> procedure may be used to determine sampling efficiencies. <br /> 14.2 Determining SE <br /> 14.2.1 SE is determined by a modified impinger assembly attached to the sampler pump,as illustrated in <br /> Figure 7. A clean PUF is placed in the pre-filter location and the inlet is attached to a nitrogen line. <br /> [Note: Nitrogen should be used instead of air to prevent oxidation of the compounds under test. The <br /> oxidation would not necessarily reflect what may be encountered during actual sampling and may give <br /> misleading sampling efficiencies.] <br /> Two PUF plugs(22-mm x 7.6-cm)are placed in the primary and secondary traps and are attached to the pump. <br /> January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-15 <br />