Page:NIOSH Manual of Analytical Methods - 5510.pdf/3

CHLORDANE: METHOD 5510, Issue 2, dated 15 August 1994 - Page 3 of 4 CALIBRATION AND QUALITY CONTROL: 8.

9.

10.

Calibrate daily with at least six working standards. a. Add known amounts of calibration stock solution to toluene containing internal standard in 10-mL volumetric flasks and dilute to the mark. Use serial dilutions as needed to obtain Chlordane concentrations in the range 0.01 to 15 µg/mL. b. Analyze the samples and blanks (steps 11 through 13). c. Prepare a calibration graph (ratio of the total Chlordane peak areas to peak area of internal standard vs. µg Chlordane). Determine recovery at least once for each lot of filters and Chromosorb 102 used. Prepare three samplers at each of five levels plus three media blanks. a. Place cellulose ester membrane filter and 100 mg of Chromosorb 102 in a bottle. b. Add calibration stock solution to the filter and Chromosorb 102 in the container with a microliter syringe. Prepare parallel blank samples with no added analyte. c. Cap the bottle. Allow to stand overnight. d. Desorb (steps 6 and 7) and analyze with working standards (steps 11 through 13). e. Prepare a graph of recovery vs. µg Chlordane recovered. Check recovery at two levels for each sample set in duplicate. Repeat recovery graph determination if checks do not agree to within 5% of recovery graph.

MEASUREMENT: 11. 12.

13. the

Set gas chromatograph according to manufacturer's recommendations and to conditions given on page 5510-1. Inject 2-µL sample aliquot using solvent flush technique or with autosampler. Make duplicate injections of samples and standards. NOTE: If peak area is above the linear range of the working standards, dilute an aliquot of the solution, reanalyze and apply the appropriate dilution factor in calculations. Measure peak areas. Divide the total Chlordane peak area (sum of five peaks; see Fig. 1) by peak area of internal standard on the same chromatogram.

CALCULATIONS: 14.

15.

Determine the mass, µg (corrected for recovery), of Chlordane found in the filter plus front sorbent section (W f), back sorbent section (W b), extract from cassette and screen (W c), and average media blank filter plus front sorbent section (B f) and back sorbent section (B b). NOTE: If W b > W f/10, report breakthrough and possible sample loss. Calculate the concentration, C, of Chlordane in the volume of air sampled, V (L):

EVALUATION OF METHOD: Method S278 was validated on June 8, 1979, [1,2,6]. The substance used to dynamically generate test atmospheres at 25 °C and 760 mm Hg was Ortho-Klor-72 (40% Chlordane), Velsicol Chemical Corporation. Collection efficiencies and recoveries were close to 1.00 in the range 6 to 120 µg per sample. No significant breakthrough was observed after 240 min of sampling an atmosphere of 1.1 mg/m 3 Chlordane at a flow rate of approximately 1 L/min. Samples spiked with Chlordane, extracted with toluene, and stored one week at room temperature gave recoveries of 96 to 100%. Overall precision ( SˆrT) was 0.07. No significant bias was found.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94