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CHLORDANE: METHOD 5510, Issue 2, dated 15 August 1994 - Page 3 of 4 <br /> CALIBRATION AND QUALITY CONTROL: <br /> 8. Calibrate daily with at least six working standards. <br /> a. Add known amounts of calibration stock solution to toluene containing internal standard in <br /> 10-mL volumetric flasks and dilute to the mark. Use serial dilutions as needed to obtain <br /> Chlordane concentrations in the range 0.01 to 15 pg/mL. <br /> b. Analyze the samples and blanks (steps 11 through 13). <br /> c. Prepare a calibration graph (ratio of the total Chlordane peak areas to peak area of internal <br /> standard vs. pg Chlordane). <br /> 9. Determine recovery at least once for each lot of filters and Chromosorb 102 used. Prepare <br /> three samplers at each of five levels plus three media blanks. <br /> a. Place cellulose ester membrane filter and 100 mg of Chromosorb 102 in a bottle. <br /> b. Add calibration stock solution to the filter and Chromosorb 102 in the container with a <br /> microliter syringe. Prepare parallel blank samples with no added analyte. <br /> c. Cap the bottle. Allow to stand overnight. <br /> d. Desorb (steps 6 and 7) and analyze with working standards (steps 11 through 13). <br /> e. Prepare a graph of recovery vs. pg Chlordane recovered. <br /> 10. Check recovery at two levels for each sample set in duplicate. Repeat recovery graph <br /> determination if checks do not agree to within 5% of recovery graph. <br /> MEASUREMENT: <br /> 11. Set gas chromatograph according to manufacturer's recommendations and to conditions given <br /> on page 5510-1. <br /> 12. Inject 2-NL sample aliquot using solvent flush technique or with autosampler. Make duplicate <br /> injections of samples and standards. <br /> NOTE: If peak area is above the linear range of the working standards, dilute an aliquot of the <br /> solution, reanalyze and apply the appropriate dilution factor in calculations. <br /> 13. Measure peak areas. Divide the total Chlordane peak area (sum of five peaks; see Fig. 1) by <br /> the peak area of internal standard on the same chromatogram. <br /> CALCULATIONS: <br /> 14. Determine the mass, pg (corrected for recovery), of Chlordane found in the filter plus front <br /> sorbent section (W f), back sorbent section (W b), extract from cassette and screen (W �, and <br /> average media blank filter plus front sorbent section (B f) and back sorbent section (13 b). <br /> NOTE: If Wb > Wf/10, report breakthrough and possible sample loss. <br /> 15. Calculate the concentration, C, of Chlordane in the volume of air sampled, V (L): <br /> C = (Wf + Wb + W,� — Bf — Bb) Mg/M 3 <br /> V <br /> EVALUATION OF METHOD: <br /> Method S278 was validated on June 8, 1979, [1,2,6]. The substance used to dynamically generate test <br /> atmospheres at 25 °C and 760 mm Hg was Ortho-Klor-72 (40% Chlordane), Velsicol Chemical <br /> Corporation. Collection efficiencies and recoveries were close to 1.00 in the range 6 to 120 pg per <br /> sample. No significant breakthrough was observed after 240 min of sampling an atmosphere of 1.1 <br /> mg/m3 Chlordane at a flow rate of approximately 1 L/min. Samples spiked with Chlordane, extracted <br /> with toluene, and stored one week at room temperature gave recoveries of 96 to 100°/x. Overall <br /> precision (SST) was 0.07. No significant bias was found. <br /> NIOSH Manual of Analytical Methods(NMAM), Fourth Edition, 8/15/94 <br />